AmphibiaWeb News of the Week Archive


(Translations may not be accurate.)

Amphibian News Archive

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Every week AmphibiaWeb offers the News of the Week to highlight breakthrough, significant, or impactful amphibian research and/or conservation actions. Below we archive the News of the Week by Year

News Archive by Year

Visit our News of the Week as they appeared below.


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Litoria rheocola
Litoria rheocola by Jodi J. L. Rowley
December 25, 2023: The first global update on amphibians in almost two decades has just been published by Luedkte et al. (2023), incorporating expertise from over 1,000 experts across the world. The study has revealed that 40.7% of all amphibian species are threatened with extinction, up from 39.4% in 2004. To put that into perspective, the current percent of threatened mammals, reptiles and birds is 26.5%, 21.4% and 12.9%. Unfortunately, the number of Extinct amphibian species has also risen to 37 species, up from 33 in 2004. Globally, the biggest threat to amphibians continues to be habitat loss and degradation, but climate change effects are now thought to be impacting a quarter of all threatened amphibian species. Thankfully, it's not all bad news; 120 amphibian species have improved their conservation status since 1980, largely due to conservation actions such as habitat protection and management. (Jodi Rowley)
Atelopus sp
Atelopus sp. by Amadeus Plewnia
December 18, 2023: Biodiversity loss is extreme in amphibians. More than three decades ago, researchers, conservationists, and other stakeholders have realized the crisis these animals are in. Due to an enormous effort, these dedicated biologists massively augmented our knowledge about declines and extinctions. While there have been many stories of success, it is difficult to determine where we stand in overcoming the amphibian extinction crisis. Neotropical harlequin toads, genus Atelopus, are the poster-child of the amphibian crisis. Many of them declined since the 1980s with several considered possibly extinct. Recently, more than 30 species have been rediscovered, raising hope for a reversing trend in the amphibian extinction crisis. Lötters and 99 colleagues (2023) use past and present population status data for 131 Atelopus species, as a 'worst-case' model to examine whether the amphibian extinction crisis is still in an emergency state. Results suggests that in all Atelopus species the conservation status has not improved. Threats remain unchanged and include habitat change and chytrid fungus spread. In addition, harlequin toads are expected to suffer from future climate change. With Atelopus serving as a 'worst-case' model, it is clear that the amphibian extinction crisis is still underway. More mitigation strategies need implementation, especially habitat protection and disease management, combined with captive conservation breeding. (Stefan Lötters, Amadeus Plewnia)
Salamandra salamandra
Salamandra salamandra by Dr. Joachim Nerz
December 11, 2023: First described in 2013, the salamander-killing chytrid fungus Batrachochytrium salamandrivorans (Bsal) has been causing steep population declines in European fire salamanders (Salamandra salamandra). Although not yet detected outside of Eurasia, there are strong concerns that Bsal might spark a new amphibian pandemic, with potential major losses of global salamander diversity that parallel the devastating impacts of its sister species B. dendrobatidis (Bd). In a recent article, Erens et al. (2023) performed a first integrative assessment of the longer-term effects of Bsal on wild European salamander populations. The results show that fire salamander populations have been able to survive for up to 10 years after the pathogen caused near-extinctions in The Netherlands and Belgium. However, affected populations survive in very low numbers, which leaves them vulnerable to further environmental threats and stochastic factors. Also, an originally small-sized population went completely extinct, highlighting the ability of Bsal to cause local extinction under adverse conditions. Bsal was furthermore seen to have variable impacts on a demographic, ecological and genetic level, which raises many new questions to be addressed in future research. In addition, the detectability of the pathogen remained low after initial population crashes, which may complicate disease surveillance efforts. (Jesse Ehrens)
Eurycea junaluska
Eurycea junaluska by Todd Pierson
December 4, 2023: The advent of genome-scale data has brought a new appreciation for the importance of hybridization and introgression in the evolutionary history of many organisms, including amphibians. These reticulate evolutionary histories can be challenging to reconstruct and may lead to discordance among inferences made from molecular and morphological datasets. Pierson et al. (2023) gathered genome-wide single nucleotide polymorphism (SNP) data from the Two-lined salamander (Eurycea bislineata) species complex—a group of widespread and abundant lungless salamanders. This study used a variety of phylogenomic methods to demonstrate that hybridization and introgression are responsible for the conflicting results of previous studies and may have resulted from a complicated history of river drainage reorganization in the region. The results highlight the inadequacy of the current taxonomy for fully describing species boundaries in the E. bislineata species complex and provide a more robust phylogenetic framework for future systematic studies. (Todd Pierson)
Geotrypetes seraphini
Geotrypetes seraphini by Brian Freiermuth
November 27, 2023: Amphibians are famous (or perhaps infamous) for their outsized genomes. Indeed, some salamanders have genomes up to 120 billion base pairs (120 GB) and, for comparison, the human genome is only 3 GB. Because large genomes are challenging to sequence, scientists have been slow to generate high-resolution genomes for amphibians. Recently Ovchinnikov et al. (2023) provided the second and third published high-resolution genomes for caecilians, specifically for Geotrypetes seraphini and Microcaecilia unicolor. By comparing the newly sequenced genomes with the first published caecilian genome (Rhinatrema bivittatum) and other vertebrate species, they made a number of interesting discoveries and observations. For example, the large genomes of caecilians are, not surprisingly, chock full of repeat sequences, which is typical of other taxa with extra-large genomes. However, whereas supersized salamander genomes are dominated by long terminal repeat (LTR) elements, those of caecilians are dominated by long interspersed elements (LINES), indicating that while both caecilians and salamanders have large genomes because of transposal elements (TEs) “gone wild”, this is not the result of failure to control a specific type of TE. Another finding is that the caecilian genomes have a large number of novel gene families (at least 1150) enriched for functions in olfaction and chemical signaling likely tied to their unique chemosensory tentacles as primary olfactory organs. Finally, the authors could find no evidence in caecilians of a developmental gene enhancer called ZRS that regulates the famous limb morphogenesis gene “Sonic Hedgehog”. Notably, snakes have been shown to have a mutant form of ZRS that, when inserted into mice, results in a limbless serpentized phenotype. The complete absence of the ZRS enhancer in caecilians implicates this gene in the convergent evolution of limblessness in caecilians and snakes. (JAM)
Conraua goliath
Conraua goliath by Marvin Schäfer
November 20, 2023: The largest known frog —even bigger than the extinct frog Beelzebufo from Madagascar— is the Goliath Frog, Conraua goliath, found only in Cameroon and mainland Equatorial Guinea. Though it has long been known that local people hunt this species, there has been little quantitative study of local knowledge and use of Goliath Frogs. Tasse Taboue and colleagues (2023) provide data from interviews of over 200 people from 11 ethnic groups as well as observations of frog hunters to document practices and inform conservation management. They document that in some communities hunting Goliath Frogs is a traditional and celebrated rite of men who hunt frogs for local consumption. Hunters prefer to hunt the largest individuals (typically females), and usually do so with fishing nets or spears. Most frogs are eaten locally, but some are sold to others in the community or to travelers, including for export to other countries. Though Goliath Frogs are formally protected by the Cameroonian government, their collection, hunting, and export remain common, and the relevant government ministry appears to not be tracking exportation. (DBlackburn)
Rana temporaria
Rana temporaria by Carolin Dittrich
November 13, 2023: The European Common frog (Rana temporaria) is an explosive breeding species, meaning that hundreds of individuals gather in early spring for a short period of time to breed. Females in these dense breeding aggregations are susceptible to losing their lives during the scramble by males to gain access to the rarer females. A study by Dittrich and Rödel (2023) shows that females are not as passive as previously thought. They display mate avoidance behaviours that include rotating (attempting to roll out the male's grip), calling (imitating the male's release call), and tonic immobility (formerly called death feigning). Tonic immobility is rarely observed in the context of mating, but is better known in predator-prey interactions, indicating high levels of stress in females during the mating season. Smaller and therefore younger females were more likely to exhibit all of these behaviours. This suggests that experience and learning may play a role in this system of sexual conflict. (Carolin Dittrich)
Myobatrachus gouldii
Myobatrachus gouldii by Ryan J. Ellis
November 6, 2023: Australia is generally considered hot, dry, and flat, making it an apparently inhospitable place for frogs. Despite this, more than 250 species call the continent home, ranging from enormous green tree frogs, to tiny brown burrowing frogs. But where did Australia’s frogs come from and when did they get there? A study by Brennan et al. (2023) provides insight into the origins of Australia’s frogs, giving age estimates to the three major frog groups found on the continent (Myobatrachoids, Pelodryadidae treefrogs, Asterophryinae microhylids) and establishing their closest relatives. This new Australian frog tree-of-life highlights the amazing adaptive potential of frogs. This includes fully aquatic and burrowing "treefrogs", and the wonderful and bizarre turtle frog Myobatrachus gouldii. In retracing the history of Australia's frogs, they find that the oldest groups such as myobatrachids, limnodynastids, and pelodryadids likely originated from Gondwana before the separation of the Australian continent. In comparison, the youngest group (microhylids) likely immigrated to Australia from New Guinea just over 10 million years ago. Finally, they provide evidence from biogeographic modelling that Australia's tree frogs arrived via dispersal from South America through Antarctica, challenging previous hypotheses regarding long distance overwater dispersal. (Written by Ian Brennan)
Ascaphus montanus
Ascaphus montanus by Amanda Cicchino
October 30, 2023: Measurements of organismal maximum heat tolerance, such as critical thermal maximum (CTmax), are often used to partly assess a species’ vulnerability to warming temperatures. However, the usefulness of CTmax for vulnerability assessments has been questioned, with two major concerns. First, these assessments assume that experimental measurements of CTmax are transferable to a natural setting. The second major concern is the perception there is insufficient variation in CTmax among populations and species for CTmax to evolve in response to increasing temperatures. Recently, Cicchino and colleagues (2023) addressed these concerns by testing the assumption that CTmax estimates are related to heat stress tolerance (mortality) in natural conditions among populations of the Rocky Mountain Tailed Frog (Ascaphus montanus). They found that CTmax was strongly related to mortality from thermal stress in temperatures mimicking natural conditions among populations, demonstrating the relevance of experimental estimates of CTmax. They also showed that relatively small differences in CTmax can have large impacts on mortality from thermal stress. This result emphasizes the potential for observed existing variation in CTmax to play a role in mediating the consequences of warming temperatures. Overall, their results provide compelling evidence that experimental measurements of CTmax can be used in assessments of vulnerability to warming temperatures. (Amanda Cicchino)
AGC logo
Amphibian Genomics Consortium
October 23, 2023: Introducing the Amphibian Genomics Consortium– genomics for amphibian research and conservation. The Amphibian Genomics Consortium (AGC) was launched this February (2023) to advance research on amphibian ecology, evolution, and conservation by facilitating the genomic study of amphibians. Amphibians, with their challenging super-sized genomes, have been the subject of relatively few genomic sequencing efforts compared to other vertebrates, and the AGC aims to remedy this by promoting collaborative, interdisciplinary research that brings together amphibian researchers from around the world. Notably, the AGC includes researchers at all career stages and with diverse expertise. The AGC aims to complement and build upon the efforts of existing genomics consortia by supporting amphibian-focused sequencing projects and other types of genome-driven research and applications. The consortium will generate genomics resources, provide computational tools, technical guidelines, and support students and early-career researchers. Presently, the AGC has over 200 members from 36 countries, a monthly virtual seminar series, and an active communication channel. If you would like to join the AGC, complete the questionnaire on their website (membership is free). We are proud to include the AGC as one of our partners.
japanesefrogs art quintinlau
Art by Quintin Lau
October 16, 2023: East Asian frogs seemingly withstand the deadly chytrid fungus, Batrachochytrium dendrobatidis (Bd), and host immune genes such as MHC (major histocompatibility complex) may play a role. Lau et al. (2023) established transcriptomic data from a range of Japanese frogs and characterized MHC genes to explore this relationship. They discovered a shared MHC class II 'supertype' (grouping functional properties) that may be important for disease resistance. This supertype is shared among all investigated Japanese and Korean species, which diverged millions of years ago. Preliminary MHC binding prediction analyses also suggested that this supertype has relatively high overall peptide binding ability (both Bd and non-Bd peptides). Their research contributes to uncovering how frogs combat Bd. (Quintin Lau)
Rhacophorus reinwardtii
Rhacophorus reinwardtii by John Wiens
October 9, 2023: Large-scale phylogenies have become indispensable for many ecological, evolutionary, and conservation studies in amphibians. However, in frogs, the widely used supermatrix trees are based on relatively few genes and are quite different from recent phylogenomic trees (those based on many genes), both in relationships among families and in ages of major clades. A new study (Portik et al. 2023) has generated the largest frog phylogeny to date. This phylogeny includes 5,242 anuran species, a 71% increase in sampling relative to the previously largest supermatrix study. The new supermatrix phylogeny also incorporates hundreds of genes from phylogenomic studies, and more than twice as many fossil calibration points (for divergence dating) as the largest supermatrix study. This new phylogeny more closely resembles recent phylogenomic trees in terms of relationships among families and divergence dates. For example, the ages estimated in the new tree for some of the largest frog clades (Neobatrachia, Hyloidea, and Ranoidea) are within 20 million years of those from these phylogenomic studies, but are 56–91 million years younger than those from the previous largest supermatrix study. This new phylogeny should offer an improved estimate for use in future comparative and systematic studies. The new tree and a set of 100 bootstrapped time-calibrated trees are available here. The authors are grateful to all the researchers who published the sequence data that underlie their study. (John Wiens)
Women in Herpetology book cover
Women in Herpetology: 50 Stories from Around the World
October 2, 2023: Available now! Women in Herpetology: 50 Stories from Around the World unveils the inspiring journeys of 50 women from 50 countries and regions who have dedicated their lives to the study of amphibians and reptiles. This groundbreaking book showcases the determination, passion, and love for these creatures that drive these women while aiming to inspire future generations of women in herpetology. The book is led by The Global Women in Herpetology project, founded by Dr. Sinlan Poo from Taiwan, Dr. Itzue Caviedes-Solis from Mexico, and Dr. Umilaela Arifin from Indonesia. All profits from Women in Herpetology will be used to establish a scholarship for students in underrepresented regions to attend international herpetological conferences to present their research. "We aim to give our first scholarships to students to attend the World Congress of Herpetology in 2024", says Dr. Arifin. "We strongly believe that every voice counts and every story matters. The road has been bumpy and our careers and lives have moments of pain and challenges. But in the midst of it all, we have also found joy," says Dr. Caviedes-Solis. Dr. Poo adds, "We came together thanks to our love for amphibians and reptiles. We hope that people can flip through the pages and immerse themselves in the rich and diverse landscapes the authors are describing and the remarkable illustrations these artists have created." Purchase the book here.

Women in Herpetology is a compilation of captivating stories from herpetologists working in diverse fields such as conservation, biodiversity, ecotoxicology, and education. It highlights their unique challenges, including limited resources and mentorship opportunities, as well as the joys and rewards they have found through their work. The book also features stunning illustrations by seventeen talented artists from around the world.

Siphonops annulatus
Siphonops annulatus by Carlos Jared
September 25, 2023: Do caecilians face selective pressure from elapid snake predators? A study by Mancuso et al (2023) searched for clues in neurotoxin fighting systems in 37 caecilian species, representing all currently known families of caecilians in the Americas, Africa, and Asia, and the Seychelles. Three types of caecilian resistance neurotoxins were identified. The study demonstrated that resistance to alpha-neurotoxins convergently evolved at least fifteen times across the caecilian tree (three times in Africa, seven times in the Americas, and five times in Asia). In addition, several species were shown to possess multiple resistance modifications acting synergistically, thus they concluded that caecilians must have undergone at least 20 separate events involving the origin of toxin resistance. In contrast, resistance in non-caecilian amphibians was found to have arisen only five separate times. Together, the mutations underlying resistance in caecilians constitute a robust signature of positive selection, which strongly correlates with elapid presence through both space (sympatry with caecilian-eating elapids) and time (Cenozoic radiation of elapids). This study demonstrates the extent of convergent evolution that can be expected when a single widespread predatory adaptation triggers parallel evolutionary arms races at a global scale. (VV)
Heleophryne purcelli tadpole
Heleophryne purcelli by Jack Phillips
September 18, 2023: Tadpoles, the aquatic larvae of frogs, seem very simple when viewed from above, with large heads and wriggling tails. When viewed from below and up-close on the other hand, it is obvious just how bizarre and alien tadpoles really are. Their small size has limited our understanding of tadpoles as there are practical difficulties to understanding how they interact with their environment and ecosystem. Annibale et al. (2023) argue that, with recent advancements in, and increased access to, slow-motion macro videography, it is now possible to start understanding the alien lives of tadpoles. One way to do this is called “autecology”, the study of individuals via close observation with a goal of understanding an organism wholistically in the contexts of their biotic and abiotic environments. The authors suggest beginning with certain groups of tadpoles, including suctorial, stream-specialists (e.g., see photo of Heleophryne purcelli). Doing so, they argue, will allow us to ask and answer new questions surrounding tadpole evolution and community ecology. The authors also suggest that these methods are not exclusive to tadpoles, but could be more broadly applied across many small, fast-moving animals. (Jackson R. Phillips)
Rana boylii
Rana boylii by Stephen Nyman
September 11, 2023: The U.S. Fish and Wildlife Service (USFWS) announced that it will provide US Federal Endangered Species Act (ESA) protections to many Foothill Yellow-legged frog populations including ESA endangered status for distinct population segments (DPS) in the South Sierra Nevada mountains, and the South Coast of California. The USFWS also granted threatened status for the populations in the North Feather River and Central California Coast. The ESA is a federal law enacted in the United States in 1973 to protect and recover species at risk of extinction and to promote the conservation of ecosystems and habitats necessary for the survival of those species. The Foothill Yellow-legged frog, named for its yellow belly and undersides of its rear legs, ranges from Oregon state to southern California, and is considered an ecological “sentinel” species serving as an important indicator for the ecological health of communities. While wide-ranging, the amphibian faces multiple threats, including altered waterflows from dams and diversions; competition with and predation by non-native species such as American bullfrogs (Rana catesbeiana) and crayfish (Pacifastacus leniusculus); disease (e.g., chytridiomycosis); precipitation and temperature changes related to climate change; high-severity wildfires; water-related recreation; and habitat conversion and degradation. This is a positive step to address the critical declines of a wide-ranging frog. (VV)
Dendrobates auratus
Dendrobates auratus by Thomas Ostrowski
September 4, 2023: Many poison dart frog species (Dendrobatidae) conduct toe-tapping behavior, the quick up-and-down movement of the hind legs´ middle toes. Observational reports suggest interactions with prey animals and/or conspecifics triggering this behavior. Schulte and König (2023) systematically tested the influence of big and small prey animals (crickets and fruit flies), as well as conspecific playback calls on toe-tapping behavior in the green-and-black poison frog (Dendrobates auratus). The experiments revealed that playback calls had no influence on the toe-tapping frequencies. Though, both prey species triggered toe-tapping in the frogs, no matter if the prey animals were small or big. Furthermore, the toe-tapping behavior was positively correlated to feeding events. Juvenile frogs, however, were excluded from the analyses. Even though they also showed toe-tapping behaviors, they tapped much less frequently than adult frogs. (Lisa Schulte)
Hyla orientalis
Hyla orientalis by Omid Mozaffari
August 28, 2023: The Chernobyl nuclear power plant catastrophe occurred over 30 years ago and researchers are now gaining a better understanding of the long-term effects of nuclear exposure to wildlife. Recently, Car et al. (2023) surveyed populations of Hyla orientalis both within and outside of the Chernobyl Exclusion Zone to assess the population structure, genetic diversity, and individual gene expression. They found that frogs inside the exclusion zone had decreased body conditions, and smaller population sizes despite ongoing migration from low to high contaminated sites. Furthermore, populations within the exclusion zone had a unique transcriptome signature and more termination mutations in their energy metabolism pathways than those outside of the exclusion zone. While these results are correlative, they suggest either a relationship with radiation exposure and highlight the need for more research into the causal relationship of radiation exposure and long-term deleterious effects in wildlife. (AChang)
Pelobates cultripes tadpole
Pelobates cultripes by Christoph Liedtke
August 21, 2023: Many animals have the ability to change their appearance to better match their backgrounds and become cryptic. Some, like the octopus, can do this very quickly by expanding or contracting different colored pigments in their skin. Others, like the snowshoe hare, change their coloration from one season to the next, by increasing or decreasing the amounts of pigments in their skin or fur. This second type of color changes tends to be a little slower, but probably is more common in the animal kingdom, including in amphibians. Liedtke et al (2023) explore the extent to which Western Spadefoot Toad tadpoles (Pelobates cultripes) can change their color in response to different backgrounds. They find that in a matter of days, these tadpoles can become completely dark or light, tracking the brightness of their environment. The tadpoles can adjust their pigmentation depending on just how bright their background is, and even reverse this color change completely. For a tadpole that lives in temporally changing ponds across the Iberian Peninsula, this is a useful trick to hide from visual predators. Color change in these tadpoles is achieved through changes in the production of eumelanin, a dark pigment commonly found in vertebrate skin. Interestingly, changes in pigmentation also are associated with changes in body shape and may have physiological consequences on the organism’s oxidative stress levels. The hormones and mechanisms that are involved in this environmentally induced color change may, therefore, be intertwined with other physiological processes, an exciting prospect for future studies. (Christoph Liedtke)
Boana faber
Boana faber by Mario Sacramento
August 14, 2023: Amphibians are found across a wide range of elevations, from sea level to above 5,000 meters, exposing them to a wide range of climates. The climate variability hypothesis predicts that organisms exposed to more temperate variation will be able to function across a wider range of temperatures. Bovo et al. (2023) tested the thermal tolerances of five species of frogs that are distributed across mountains in Brazil's Atlantic Rainforest in a variety of microhabitats, including Boana faber, Dendropsophus minutus, Leptodactylus latrans, Physalaemus cuvieri, and Rhinella icterica. They found differences among species in temperature tolerance, but did not always find that broader temperature variation at increasing elevations correlated with broader temperature tolerance. In addition, they did not find a consistent difference in water loss or water uptake across altitude or climates. Overall, they did not find strong support for the climate variability hypothesis or for elevation shaping these physiological traits. (MWomack)
Bufo bufo
Bufo bufo by Frank Teigler
August 7, 2023: No one likes mosquitos, or the diseases they transmit, but there is a positive link between their abundance and human-caused landscape alterations. Conversely, while amphibian density has been shown to have a negative relationship on mosquitos density, amphibians also are negatively impacted by human modifications to their habitat. Perrin et al. (2023) examined the interaction of these relationships with a survey of 77 anthropized ponds in western Switzerland. While their methods were indirect, their structural equation models and path analyses point to ponds with amphibians having reduced abundance and diversity of mosquitoes, likely through limiting competition and predation by amphibians. Their analysis also found that ponds were more likely to have amphibians if they were deeper and older, as mosquitos often colonize new ponds immediately while it takes a few years for their predators to do so. The authors argue that removing wetlands to reduce mosquito populations is counterproductive as it impacts mosquito predators more than mosquitos, and they encourage the development of more measures to protect amphibians. (AChang)
Herpele squalostoma
Herpele squalostoma by Marcel Kouete
July 31, 2023: Previous studies on frogs and salamanders suggest a limited correlation between parental care and the transmission of microbiome from parent directly to the offspring, or vertical microbiome transmission. However, caecilians— among the most poorly known of terrestrial vertebrates and the most elusive amphibians— have not been investigated in this context. The oviparous, direct-developing caecilians present a unique opportunity for studying parent-offspring interactions because they exhibit elaborate forms of parental care. Juveniles both feed on the skin of the mother and, at least in some species, imbibe a fluid from her cloaca, both quite likely leading to vertical bacterial transmission. Kouete et al. (2023) studied the microbiomes of Herpele squalostoma, an oviparous, direct developing caecilian from Central Africa that engages in parental care through skin-feeding. Using 16S rRNA metabarcoding. they found that juveniles shared an important proportion of their skin and gut microbiome with the skin and gut of mothers, including high similarities with the mothers' skin. In addition, nitrogen stable isotope (15N) values of juvenile skin were approximately three times higher than that of the mothers, indicating a higher trophic position for juveniles due to skin-feeding. (Marcel Kouete)
Dendropsophus marmoratus
Dendropsophus marmoratus by Jasper van Dalen
July 24, 2023: As the most imperiled vertebrate class, amphibians face a slew of threats. Because amphibians use their skin for respiration and the regulation of ions, but have a higher potential for evaporative water loss, climate change, which is expected to bring higher average temperatures and unpredictable rainfall, is a particular risk. Rollins-Smith and Le Sage (2023) reviewed the current literature on the effects of heat stress and desiccation on amphibian immunity. While responses are varied, the overarching result from studies indicate that heat stress and desiccation can suppress the innate and lymphocyte-mediated responses by stimulating the hypothalamus pituitary-interrenal axis. Additionally, elevated temperatures can reduce the microbial communities of both the skin and gut, causing decreased immunity to pathogens and reduced nutrient uptake. These effects are particularly striking in larvae, resulting in the loss of recruitment. While these results are alarming, more studies are needed to understand how amphibians adapt to climate change, especially in understudied clades, such as salamanders, and underrepresented geographic regions. (AChang)
Global Women in Herpetology book promo
Global Women in Herpetology Project
July 17, 2023: Herpetology, the study of amphibians and reptiles, has been a male-dominated field with most of its history rooted in Western-centric scientific tradition while many biodiversity hotspots of amphibian diversity occurring outside of the US and Europe. To bring some light to less visible herpetologists, Drs. Umilaela Arifin, Itzue Wendolin Caviedes Solis, and Sinlan Poo initiated the Global Women in Herpetology Project, first establishing an international registry of women scientists to facilitate networking, support, and visibility. Already, it represents 50 countries and regions with women at all stages of their career, from students to professionals. Their passion extended to a recently released book that beautifully illustrates the fieldwork, challenges, careers, and, of course, the amphibians and reptiles which are the focus of 50 women in herpetology from all continents where amphibians and reptiles occur. “By sharing our journey in life and career, we will collectively put a spotlight on the diversity of women in our field. We hope this effort will encourage the next generation of herpetologists to follow their dreams.” You can buy this uniquely inspiring book on the Global Women in Herpetology Kickstarter site until it moves to a book publisher. (MK)
Odontophrynus juquinha
Odontophrynus juquinha by Fernando Leal
July 10, 2023: Pollen is potentially a nutritious food source and widespread in the right season. Whether tadpoles take advantage of pollen and effectively consume pollen may depend on whether they can digest the grains despite its hard outer coats, the season, and feeding morphology. Kloh et al 2023 examined three frog species with different tadpole feeding behaviors to investigate the role of pollen in their diets: Phasmahyla jandaia, which feeds at the water’s surface; Scinax curicica, which feeds in the water column; Odontophrynus juquinha, which feeds on the bottom. Comparing gut contents, pollen digestion, developmental stages, morphology, and seasonality, they found that surface-feeding tadpoles were generally the better consumers and consumed the most pollen. Some seasonal variation existed in the water-column feeders with pollen consumption high in the dry season likely when other food sources are more scarce. They did find all three species consumed pollen regardless of stage. Their work highlights an overlooked food source for amphibians and the importance of conserving the food web of riparian habitats. (MK)
Ichthyosaura alpestris
Ichthyosaura alpestris by Javier Sunyer
July 3, 2023: Conservation management is challenging for several reasons, including the variety of local stressors that contribute to the decline of a species or community. One common challenge is the gap between research recommendations and the ability to implement those recommendations. Moor et al. (2022) show in their decades-long analysis the effects of mitigation through habitat (pond) creation on the management of twelve declining pond-breeding amphibian species in Switzerland. They analyzed 20 years of data in the densely populated state of Aargau, Switzerland, and found the addition of hundreds of new ponds to the landscape stopped the decline or stabilized the populations of the majority of the monitored amphibians. They demonstrated the significant positive impact of restoring habitat dynamics by increasing habitat availability and connectivity, and how large landscape conservation efforts can benefit threatened amphibians despite all other declines factors. (AChang)
Anaxyrus fowleri metamorph
Anaxyrus fowleri by Sinlan Poo
June 26, 2023: Many frogs all over the world are in danger of extinction, but scientists have strategies to try and prevent mass extinctions. Conservation translocation—movement of animals from one place to another—is one such strategy. However, there is no reliable information on whether this method works in the wild for frogs. Researchers from the Memphis Zoo and Oregon State University (Poo et al. 2022) set out to find out: can frogs produced from cryopreserved sperm be used to create new and healthy populations in the wild? Using Fowler's toads (Anaxyrus fowleri), they found that tadpoles from cryopreserved sperm and post-metamorphic toadlets were smaller than their natural counterparts. They project that these early-stage differences in growth continue to become substantial differences in final life fecundity and population trends. Their study shows that more work needs to focus on cryopreservation technologies in order to make them feasible for conservation translocation. (Read more "Can freezing frog sperm help with conservation efforts?") (Sinlan Poo)
Ranitomeya imitator
Ranitomeya imitator by Mark Aartse-Tuyn
June 19, 2023: Parental care in frogs provide an excellent opportunity to examine the evolution of complex sociality, specifically whether increased complexity of care is correlated with the evolution of novel or context-dependent signals as frogs have been models for both animal communication and parental care diversification. Moss, Tumulty, and Fischer (2023) studied the Mimic Poison Frog (Ranitomeya imitator), a remarkable species displaying monogamy, pair bonding, and biparental care of eggs and tadpoles. Specifically, the authors address whether calls elicited in the context of egg feeding – a cooperative parental behavior in which males lead females to tadpole deposition sites and stimulate them to lay trophic eggs – reflect the evolution of novel signal elements. Combining acoustic and video recordings of pairs in the laboratory, they repeatedly sampled calls of the same individuals in three social contexts – advertisement, courtship, and egg feeding – and characterized and compared call types. Consistent with their prediction, egg feeding calls were distinct from either ancestral call type. These calls have lower dominant frequencies and clipped pulse rates. Despite these differences, there was still considerable overlap between call types, both within and between individuals. This overlap suggests that parental care is coordinated through the use of multimodal (e.g., visual and olfactory, in addition to acoustic) cues. Their study highlights the complexity of anuran communication systems and the need to characterize vocal repertoires across a an array of social contexts. (Jeanette Moss)
Feihyla hansenae
Feihyla hansenae by Sinlan Poo
June 12, 2023: A study on Feihyla hansenae, a rhacophorid treefrog from Thailand with terrestrial eggs, shows that embryos are capable of hatching early to escape flooding, and that failure to hatch results in mortality. By incorporating natural and experimental data into Monte Carlo methods to simulate and compare survival probabilities with and without hatching plasticity, Poo et al. (2023) found an overall increase in submergence survival due to hatching plasticity. As intensity and consistency of rainfall become more unpredictable and more variable due to climate change, there is a clear need for more life history data to increase the accuracy of our predictions on how animals may respond. These results add to the growing body of literature surrounding climate-correlated effects on poorly-studied amphibian populations. (Sinlan Poo)
Physalaemus cuvieri
Physalaemus cuvieri by Mario Sacramento
June 5, 2023: Foam nests are a unique reproductive strategy used by frogs providing eggs and larva protection from desiccation, predation, and suffocation while also aiding in fertilization and providing a food source for developing larvae. More recently, the protein and carbohydrate rich foam also has been associated with the vertical transfer of beneficial microbial communities in rhacophorid frogs. Monteiro et al. (2023) characterized the protein composition and microbiome of the nests of three Leptodactylid species: Adenomera hylaedactyla, Leptodactylus vastus, and Physalaemus cuvieri, with each representing a different spawning habitat type. They found that protein composition was species-specific and was influenced more by spawn habitat type and nest size than phylogenetic relatedness. Many of these proteins were previously unidentified. Additionally, the microbiome community of the nest was unique from the surrounding environment and the adult skin microbiome. These findings show that foam nests have a key functional role in reproduction and highlight the need for conservation efforts to protect nests from anthropic pressures, as each nest has a unique microenvironment. (AChang)
Xenohyla truncata
Xenohyla truncata by Carlos Henrique de-Oliveira-Nogueira
May 29, 2023: De-Oliveira-Nogueira et al (2023) reports a new behavior and relationship between an amphibian and plant: the South American tree frog Xenohyla truncata has been observed feeding on nectar and flowers of the Brazilian milk fruit tree Cordia taguahyensis. The flower structure of this tree species allows the frog to enter and exit the flower easily. During their feeding activity, the pollen grains adhere to the frog’s back and are transported to other flowers while visiting them. Based on this observation, the authors suggest that X. truncata is not only a seed disperser, but also a potential pollinator of C. taguahyensis, or even of other plant species with similar floral structure. Nectar-feeding is an unique natural history behavior among frogs and highlights the importance of fundamental natural history information for this endemic tree frog species, which exclusively lives in the rapidly disappearing Restinga habitat on the coast of Rio de Janeiro in Brazil. With expanding development and habitat destruction, it is feared that losing this frog species, currently threatened with extinction, also means the extinction of a unique amphibian-plant interaction, especially important as it is a first known for a frog. Thus, conservation of this tree frog species has heightened stakes. (UArifin)
Andrias davidianus
Andrias davidianus by Axel Hernandez
May 15, 2023: Infectious disease has been linked to several instances of amphibian population decline and is hypothesized to contribute to worldwide amphibian declines. As a result, there is urgency to better understand host-pathogen-environment interactions in amphibian communities. Researchers can take advantage of cultured cell lines to investigate host-pathogen-environment interactions in controlled experiments that do not require the use of live animals. Amphibian cell lines thus can provide an important and more accessible first step in addressing open research questions which can be followed up with live animal studies. Douglas et al. (2023) reviewed the existing amphibian cell line resources and literature and found that the amphibian invitrome, the collection of amphibian cell lines, consists of at least 159 distinct amphibian cell lines originating from 23 species belonging to five frog families and four salamander families. Despite this impressive history of cell line resources and many curated lines, few have been used to investigate amphibian cellular immune responses. The authors propose that the amphibian invitrome has the potential to transform our understanding of amphibian immune responses at a mechanistic level while limiting use of live amphibians. (MWomack)
Ranitomeya imitator
Ranitomeya imitator by Lars Fehlandt
May 8, 2023: Neotropical poison frogs are known for their intensive parental care. Male or female parents will carry their tadpoles to bromeliads to provide them with small pools of water where they can develop, safe from fishy predators. In these nutrient poor habitats, some species have evolved egg-feeding, where females lay unfertilized eggs for the tadpoles to eat. In the Peruvian mimic poison frog, Ranitomeya imitator, parents form a pair bond and cooperate in the care of their tadpoles. In this system, Weinfurther et al. (2023) provide preliminary evidence of a symbiotic protist in the guts of the tadpole. In comparative experiments, they switched the diets of R. imitator tadpoles (eggs) with the ancestral diet (detritus) consumed by a related species (R. variabilis) without egg-feeding, and did the reverse (with control treatments for both species). Analyses of gut gene expression revealed elevated expression of proteases in the R. imitator field egg-fed treatment. These digestive proteins came from parabasalians, a group of protists known to form symbiotic relationships with hosts that enhance digestion (especially in termites). Genes encoding these digestive proteins are not present in the R. imitator genome, and phylogenetic analyses shows these mRNA sequences were from parabasalian protists. Bar-coding analyses of the tadpole eukaryotic microbiomes further confirmed this discovery. More study is necessary to confirm whether these parabasalians aid R. imitator tadpoles in protein/ lipid digestion in an egg diet. This may have enabled the exploitation of a key ecological niche (very small, nutrient-poor pools), allowing R. imitator to expand into an area with ecologically similar species (e.g., R. variabilis and R. summersi). In turn, this may have enabled a Müllerian mimetic radiation, one of only a few examples of this phenomenon in vertebrates. (KSummers)
Boana prasina
Boana prasina by Germano Woehl Jr.
May 1, 2023: Symbiotic skin microbial communities and skin secretions have been studied in frogs for their immunological effects for decades, however, there are still much to discover about all the other roles they may play. Brunetti et al. (2023) examined Burmeister's Treefrog, Boana prasina, for evidence of chemical signaling and found that their skin secretions contained 10 different compound classes of volatile chemicals, some of which were produced by symbiotic Pseudomonas sp. bacteria. Moreover, these odors varied by sex, which in tandem with acoustic signaling, could play a chemical signaling role in sex recognition and assessment during breeding. These findings open the door to questions that could improve our understanding of amphibian breeding behavior and symbiotic associations. (AChang)
Ranitomeya reticulata
Ranitomeya reticulata by Frank Steinmann
April 24, 2023: In a 2023 study, Loeffler-Henry et al. provide new insights into the evolution of aposematism, that is, the warning coloration combined with a chemical defense. They review the apparent paradox inherent in the evolution of aposematism: How can new brightly colored mutants survive when they will attract predator attention before the predators have learned that bright coloration is associated with toxicity? While a variety of potential solutions to this puzzle have offered, none have been definitively demonstrated to apply in general. Here, they focus on the hypothesis that aposematism evolved in gradual stages involving the prior evolution of facultatively presented signals, such as bright colors concealed by limbs, or bright coloration of the underbelly of the animal (and revealed only upon the close approach of a predator). The conditions favoring the evolution of this type of coloration are likely to be much less restrictive, and yet they provide a clear pathway to the evolution of overall bright coloration. The authors carry out an extensive series of phylogenetically- controlled comparative analyses using maximum- likelihood methods, which allows them to make statistically supported inferences about the evolutionary pathways of the evolution of both coloration and defense (toxicity). The results provide support for the hypothesis that conspicuousness evolved via an indirect pathway in which facultative conspicuous coloration evolved first and provided pathways for full conspicuousness to evolve later. There is still considerable work to be done in terms of identifying the specific evolutionary mechanisms that facilitated the evolution of aposematism through each gradual step, but this study provides a valuable roadmap for those kinds of analyses. (KSummers)
Pseudophilautus lunatus
Pseudophilautus lunatus by Madhava Meegaskumbura
April 17, 2023: In a phylogenetic analysis, Ellepola et al (2022) investigates the roles of climate, ecological opportunity and key evolutionary innovations (KEI) in the diversification of rhacophorid frogs, which represent six percent of global amphibian diversity, four distinct reproductive modes, and spans a climatically variable area across mainland Asia, associated continental islands, and Africa. Using a complete species-level phylogeny, they report near-constant diversification rates but a highly uneven distribution of species richness. Montane regions on islands and some mainland regions have higher phylogenetic diversity and unique assemblages of taxa; the study identifies these as cool-wet refugia. Starting from a center of origin, rhacophorids reached these distant refugia by adapting to new climatic conditions (‘niche evolution’-dominant), especially following the origin of KEIs such as terrestrial reproduction (in the Late Eocene) or by dispersal during periods of favorable climate (‘niche conservatism’-dominant). (VV)
Rana catesbeiana
Rana catesbeiana by Rob Schell
April 10, 2023: What compounds do amphibians taste? What role might taste play in the biology of amphibians as they develop from larvae to adults? Using comparative genomics, Hao et al. (2023) found unexpected diversity in the Tas2r taste receptors that detect bitter compounds, more than in any other vertebrate group. By looking at the differential expression of the nearly 200 Tas2r genes in the American Bullfrog (Rana catesbeiana), they found that tadpoles and adults differently express some genes at high levels. This suggests that variation across development in expression of these bitter receptors is related to the different foods (and presumably different preferences) between herbivorous larvae and insectivorous adults. Interesting areas for further research include how these receptors might be distributed within the mouth, including on the unusual taste “discs” of frog tongues, as well as how closely related species might differ in bitter receptors and thus preferences for different prey. (DBlackburn)
Ambystoma maculatum
Ambystoma maculatum by Todd Pierson
April 3, 2023: Researchers are finding amphibians move more frequently and farther across landscapes than often assumed, which has broad conservation implications. Davis et al. (2023) carried out an impressive six-year capture-mark-recapture study across 12 wetlands in Pennsylvania, US, and showed that adult Spotted Salamanders (Ambystoma maculatum) move a surprising distance both within and between breeding seasons. Six percent of males moved among wetlands each day, and in high density populations, males tended to return to the same breeding wetland year after year (had higher site fidelity). Females exhibited higher interannual site fidelity and dispersed farther than males between breeding seasons. This study and others that track amphibian movements are improving our understanding of breeding dispersal probabilities and capabilities. (MW)
Astylosternus diadematus
Astylosternus diadematus by Daniel Portik
March 27, 2023: Pandemics in amphibians, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), have resulted in biodiversity loss at a global scale. Genomic data suggest a complex evolutionary history of Bd lineages that vary in pathogenicity. Africa harbors a significant proportion of global amphibian biodiversity, and multiple Bd lineages are known to occur there; yet, despite the decline of many host species, there are currently no described Bd-epizootics. Ghose et al. (2023) describes the historical and recent biogeographical spread of Bd and assess its risk to amphibians across the continent of Africa. Their study provides a 165-year view of host-pathogen interactions by (i) employing a Bd assay to test 4,623 specimens (collected 1908–2013); (ii) compiling 12,297 published Bd records (collected 1852–2017); (iii) comparing the frequency of Bd-infected amphibians through time by both country and region; (iv) genotyping Bd lineages; (v) histologically identifying evidence of chytridiomycosis, and (vi) modeling future Bd risk. They found a pattern of Bd emergence beginning largely at the turn of the century. From 1852–1999, Bd prevalence is low (3.2% overall) with limited geographic spread, but after 2000, prevalence sharply increases (18.7% overall) with wider geographic spread and multiple Bd lineages that may be responsible for emergence in different regions.They found Bd risk to amphibians to be highest in much of eastern, central, and western Africa. The study documents a largely overlooked yet significant increase in a fungal pathogen that could pose a threat to amphibians across an entire continent and emphasizes the need to bridge historical and contemporary datasets to better describe and predict host-pathogen dynamics over larger temporal scales. (VV)
Oreophryne anser
Oreophryne anser by Fred Kraus
March 20, 2023: New Guinea – the world’s largest tropical island – is famous for its rugged topography, with snow-capped mountains reaching 4,884 m in elevation (16,024 ft), and a multitude of deeply incised valleys that make ground-based overland travel virtually impossible. This topography is highly conducive to localized speciation and small-range endemism. Oliver et al. (2022) focused on the amphibians of this imposing landscape and find that New Guinea holds the world’s most diverse and intact insular amphibian fauna, with over 7% of global frog species (534 currently recognized species) distributed across less than 0.7% of the world’s land area. Remarkably, the scale of the New Guinea frog fauna is almost certainly substantially underestimated as the authors are aware of about 190 species in collections that have yet to be described. Furthermore, most of the known species were described from the much better surveyed eastern half of the island that represents the country of Papua New Guinea. The frog fauna of the western half of the island (Papua Province, Indonesia) remains relatively understudied and promises to hold additional species beyond the ~700 estimated by the authors. The composition of the New Guinea frog fauna is almost entirely restricted to three families (Microhylidae, Hylidae, Ceratobatrachidae), with the direct-developing microhylids dominating. New Guinea’s rugged topography has likely contributed to its amazingly diverse fauna and simultaneously prevented the sort of large-scale anthropogenic habitat destruction that has allowed the fauna to remain largely intact (only 6% of assessed species are listed as threatened). (JM)
Thoropa taophora
Thoropa taophora by Mauro Teixeira Jr.
March 13, 2023: Brazil is considered a mega-diverse country for amphibian diversity (1159 amphibian species known so far). However, it is also home to one of the global hotspots of amphibian decline, the coastal Atlantic Forest. To understand the history, nature, and response of species to the precipitous declines, Toledo and colleagues (2023) closely analysed surveys, reports, and museum records with environmental, climatic, and disease data. Their study more than doubled the number of population declines reported in previous studies, placing the Brazilian Atlantic Forest as a global hotspot of amphibian declines with one of the highest rates of declines and extinctions. The height of decline appears to be in 1979 within a decades long trend. Populations, if they recovered, sometimes took as long as 30 or more years. Their use of museum collections showed that specimen records matched the spatiotemporal patterns of declines and extinctions, including the impact of chytridiomycoses; they suspect that historic declines might have impacted many more amphibian populations and species. They also sought correlations of life history traits and phylogeny to help explore patterns of decline. They note some families were disproportionally impacted (specifically Cycloramphidae, Hylodidae, Phyllomedusidae). Their comprehensive report will be an essential guide to conservation, management, and disease surveillance to protect this important amphibian ecology. (MK)
Hyalinobatrachium fleischmanni
Hyalinobatrachium fleischmanni by Peter Janzen
March 6, 2023: One of the most remarkable forms of camouflage observed in nature involves transparency in glass frogs of the family Centrolenidae. These frogs, which are arboreal and typically perch on leaves, have highly transparent ventral skin through which their organs can be clearly seen, as well as green dorsal coloration and green bones that presumably enhance their camouflage. One feature that might disrupt their camouflage is the presence of red blood cells, which are easily seen through the transparent ventral skin. Recently Taboada et al. (2022) showed that the glass frog species Hyalinobatrachium fleischmanni increase their transparency while resting by two to three-fold by removing about 89% of their red blood cells from circulation and packing them within their liver. This exciting new discovery not only provides new information on the nature of transparency in glass frogs but may also inform biomedical research because the ability to densely pack red blood cells into the liver without clotting could have important human health consequences. (JM)
Nectophrynoides vestergaardi
Nectophrynoides vestergaardi by Martin Vestergaard
February 27, 2023: Evolutionary transitions in reproductive modes and life-cycles in amphibians has long been a target of study to understanding the diversity of life. Liedtke et al (2022) compares large-scale macroevolutionary patterns across the three orders of amphibians: frogs, salamanders, and caecilians, and includes reproductive and phylogenetic data for 4,025 species. Their analysis indicate aquatic larvae as ancestral for all three groups. The most frequent transitions in each group are to relatively uncommon states: live-bearing in caecilians, paedomorphosis in salamanders, and semi-terrestriality in frogs. All three groups show transitions to more terrestrial reproductive modes, but only in caecilians have these evolved sequentially from most-to-least aquatic. Diversification rates are largely independent of reproductive modes. However, in salamanders, direct development accelerates diversification whereas paedomorphosis decreases it. Overall, the study reports a widespread retention of ancestral modes, decoupling of trait transition rates from patterns of species richness, and the general independence of reproductive modes and diversification. (VV)
Rhinella marina
Rhinella marina by Rachel Keeffe
February 20, 2023: How do frogs swallow their food? While the mechanics of the frog tongue are well-studied for the prey capture phase of the feeding cycle, little is known of how structures in the mouth move once it is closed. Recent work by Keeffe et al. (2022) investigated the functional morphology of the hard and soft tissues involved in feeding behaviors in the Cane toad, Rhinella marina. Using a combination of high-speed X-ray video, 3D animation software, and dissection, they assessed the role of the skull, jaw, pectoral girdle, tongue, and hyoid apparatus (skeleton supporting the tongue) during a complete feeding cycle. Their results suggest the hyoid apparatus plays an important role in prey transport, potentially helping remove prey from the sticky tongue pad prior to swallowing. They also found that the tip of the tongue consistently travels behind the back of the skull during swallowing, and that tongue protrusion comprises only a small portion of a full feeding cycle. This work raises new questions about the evolution of feeding in frogs, as well as how the observed diversity across frogs in the skeleton of the shoulder and tongue may influence feeding kinematics. (Rachel Keeffe)
Ranitomeya imitator
Ranitomeya imitator by John Clare
February 13, 2023: Poison frogs, with bright colors and potent skin toxins, represent iconic examples of aposematism in rainforests throughout South and Central America. These frogs are also known for intensive parental care– parents carry tadpoles to small pools (phytotelmata) and some species provide trophic eggs as food for their offsprings. Much interest has focused on the question of whether poison frog tadpoles can acquire toxins for protection from predators by consuming eggs from their mothers. Studies have shown two species of Oophaga provide toxins to their tadpoles via obligate trophic egg feeding. In contrast, in Ranitomeya variabilis (and related R. fantastica, R. summersi) do not provide unfertilized eggs to their tadpoles (instead, they subsist on detritus, algae, and insect larvae), although they will sometimes lay fertilized clutches in or above pools that are later cannibalized by tadpoles. Villanueva et al. (2022) investigate this issue in a third species of Oophaga (O. granulifera) and in Ranitomeya imitator and R. variabilis. They found that while O. granulifera receives toxins in its eggs (like other members of this genus), that was not true for either species of Ranitomeya. They infer the degree to which egg feeding is facultative (high in R. variabilis, low in R. imitator, not facultative in Oophaga) is related to the evolution of toxin transfer via egg feeding. This is only a single comparison between the Oophaga and Ranitomeya lineages, so further studies will be necessary for definitive conclusions, but their study provides a fascinating and promising first pass at this question. (KSummers)
Paramesotriton chinensis
Paramesotriton chinensis by Jessica Miller
February 6, 2023: Evolutionary history and biogeographic patterns give us insight into how species respond to paleogeographic and paleoclimatic changes over a shared landscape, and these in turn can provide a guide for conservation management. In southern China, the landscape is a transitional mosaic with dramatic changes in elevation ranging from an average of 4000 m a.s.l to sea level. Yuan et al. (2022) used multi-locus genetic and environmental data from 78 sites to investigate phylogeographic patterns in the southern Chinese newt genera of Cynops, Paramesotriton, and Pachytriton. Their results showed consistency with major geological events, such as the uplift of the Qinghai-Xizang (Tibet) Plateau. Furthermore, variation in summer monsoons and the complex landscape of montane/submontane forest with lowland areas resulted in barriers that act as both ‘museums’ or refugia of old lineages and ‘cradles’ for new species diversification. These findings can provide a backbone for genetically informed management plans, but education and public awareness are crucial to preventing habitat disturbance and over-harvesting of vulnerable species. (AChang)
Bombina variegata
Bombina variegata by Andreas Nöllert
January 30, 2023: Some amphibians are able to persist in human-modified habitats, including within cities and intensively managed lands. Which mechanisms allow persistence in such environments? Cayuela et al. (2022) conducted a comprehensive analysis of mark-recapture studies of Yellow-bellied Toad (Bombina variegata) populations across a range of anthropic habitats. These toads breed in early-succession ponds and small pools of natural or anthropic origin. Life history traits can change along the gradient from natural to anthropic habitats according to two demographic scenarios. In the first scenario, the risk of adult mortality decreases with anthropization, associated with concomitant decreases in predation and parasitism rates. In the alternative scenario, increased exposure to contaminants, invasive species, ecological mismatches and other processes promote higher adult mortality risk in human-modified habitats. In this scenario, increased recruitment can compensate for increased adult mortality. Cayuela and collaborators estimated adult recruitment, adult survival, lifespan, and senescence rate from 67 populations of the yellow-bellied toads across western Europe. They convincingly show that toads in anthropogenic habitats have lower adult survival, shorter lifespan, and accelerated senescence than toads in natural habitats. Compensatory recruitment indeed occurs in anthropogenic habitats, where average adult recruitment is 93% higher than in natural habitats. Increased human land disturbance might promote creation of breeding habitats conducive to higher adult recruitment. These findings suggest the important role of human disturbance for maintaining populations of amphibians using early-succession habitats. (ACatenazzi)
Boana geographica
Boana geographica by Alberto Sanchez-Vialas
January 23, 2023: Biological reserves provide protected refugia against human-mediated habitat degradation, which is one of the strongest conservation concerns for amphibians. The Manu Biosphere Reserve is one of the most biodiverse places on earth with over 155 amphibian species. Serrano-Rojas et al. (2022) surveyed 70 of the amphibian species recorded in the Manu Biosphere Reserve within five sites that span a land-use gradient in the park buffer zone (immigrant agricultural land, forests used by three Indigenous communities, and a regenerating forest) in addition to a reference site in its core protected area. They found the richness and diversity of amphibians in the regenerating forest and the indigenous communities’ forests were similar to that of the core protected area, whereas agricultural land had lower richness and was dominated by generalist species. Their findings underscore that supporting sustainable livelihood activities, cultural practices, and forest protection, which are observed in many Indigenous communities, could help avoid a shift towards intensive agriculture, fulfilling a crucial conservation role. (MWomack)
Rana luteiventris
Rana luteiventris by Andreas & Christel Nöllert
January 16, 2023: Amphibians may be affected by climate change more than other terrestrial vertebrates, and they have the higher rates of decline in recent years. The Columbia Spotted Frog (Rana luteiventris) is a widespread North American frog that occurs across a variety of climate gradients, from subalpine forests to semi-arid deserts. Pilliod and colleagues (2022) marked 15,885 adult Columbia Spotted frogs with subdermal transponders, with 33% recaptured at least once during their long term study (11-16 years depending on site). Within each population, adult survival and recruitment rates respond uniquely to seasonal temperature and precipitation variables, especially in winter and spring. Seasonal rain is a weak predictor of adult survival but was a useful predictor of juvenile recruitment, especially in three of the populations. Recruitment rates for each population peaked with different environmental gradients, depending on the amount of winter snowfall, and fall temperature and moisture levels. Thus recruitment may be responding to local conditions independently within each population. Their work emphasizes that local conditions and climate gradients need to be accounted for when managing climate effects on populations of amphibian species with broad geographic ranges. (CS)
Pristimantis enigmaticus
Pristimantis enigmaticus by Amadeus Plewnia
January 9, 2023: An important life history trait is body size, which can be affected by environmental and evolutionary factors. Acevedo et al. (2022) examined these relationships in the specious, neotropical genus Pristimantis, which has a distribution across wide latitudinal and elevational ranges. Using body size data for all 584 known Pristimantis, phylogenetic information from 257 species, and information on their environments, the authors found that the body size of males, females, and sexual size dimorphism were correlated with climatic variation associated with heat balance (temperature), water availability (precipitation), and habitat availability (elevation). Additionally, despite the majority of species displaying sexual size dimorphism, their trend ran opposite to Rensch's rule, where males are larger then females. This correlation may be the result of fecundity selection, reproductive energy requirements, or heat balancing. Although separate clades show evidence that they are experiencing different selective pressures, the rate of body size evolution appears to be decelerating as the trait reaches an optimum. As this study provides a case for bioclimatic factors in body size evolution, it is a good launching point to generate future selection and macroevolutionary hypotheses of sexual size dimorphism. (AChang)
Oophaga pumilio
Oophaga pumilio by Gonçalo M. Rosa
January 2, 2023: Happy New Year’s! Reflecting on 2022, we had a particularly productive year at AmphibiaWeb. One of the most visible improvements this year is (the much needed) new home page! All of the old links are still present but much more presentable. We hope you love the new home page as much as we do. We published the first "State of the Amphibia" paper (Womack et al 2022) in which we summarize the major research and data trends on Amphibia in the last 5 years. We aim to repeat this every five years to establish a record of and facilitate amphibian research and conservation. We end the year with 152 newly described species (20 mantellids frogs alone thanks to Scherz et al 2022!), a little less than the five-year average of 158. We also nearly doubled the number of new species accounts (140) which reflects both the new editing forms and efforts by student apprentices, but we hope to release even more accounts next year. In 2023, we will launch a new program to expand our network of experts and trained authors-- look out for announcements and opportunities to connect with us. We hope to have an equally productive 2023, so please keep an eye out for new projects, new data-driven pages and graphics, and the same committment as we continue to serve as the knowledge-hub for amphibians.


back to News by Year
Rana sylvatica
Rana sylvatica by Adam Crane
December 26, 2022: The evolution of chemical alarm cues has been puzzling to evolutionary biologists. At first glance, the cues appear to only help other individuals, not the preyed-upon individual that produced and released the cues (the 'sender'). However, according to theory, the evolution of communication systems requires benefits to senders. Releasing alarm cues can benefit the sender’s genes by warning their nearby kin, but prey often do not associate based on kinship. There is some evidence that alarm cues can protect against certain parasites and pathogens. However, an alternative hypothesis is that alarm cues attract additional predators to an attack, thereby interfering with it, and allows the prey to escape. This is known as the 'Predator Attraction Hypothesis'. Previous studies on fishes have provided support for this hypothesis, but amphibians had not been tested before. Crane et al. (2022) used Tiger salamander (Ambystoma mavortium) larvae (predators) and Wood Frog (Rana sylvatica) tadpoles (prey) to test this hypothesis and found the predators were attracted to alarm cues. This was even more apparent when the salamanders had prior experience with tadpole prey. When two salamanders were present, they rushed their attacks and were less accurate than when alone. This increased the chances of escape for tadpoles. We also found that the mere presence of visual and chemical cues from a second salamander caused enough of a distraction to increase tadpole survival. All together, their results support the Predator Attraction Hypothesis for the evolution of chemical alarm cues in tadpoles. (Adam Crane)
Atelopus ignescens
Atelopus ignescens by Kyle Jaynes
December 19, 2022: Harlequin frogs (genus Atelopus) are one of the most iconic groups decimated in the amphibian decline crisis. It is difficult to know when a species is truly extinct and to study populations on the brink of extinction due to their population size and endangerment. Standalone reports of Atelopus species rediscoveries (i.e., once missing but found again) have grown substantially over the last decade, but their extent across the imperiled genus and population status’ have remained elusive in most cases. Jaynes et al. (2022) characterized Atelopus rediscoveries to investigate temporal, geographic, and genomic diversity patterns of persisting populations. They estimate that between 18 and 32 species have been rediscovered in the genus since 2002, representing 25-37% of once missing species. Rediscoveries are documented everywhere the genus occurs – spanning 100 m to > 3500 m in elevation, and geographic patterns closely matching known species abundance in each country. Genomic analysis in the geographic epicenter of Atelopus rediscoveries (Ecuador) revealed a pattern of decreased heterozygosity the longer a species was considered missing or extinct, and loss of heterozygosity over time in one species with historical comparisons. This study shows that persistence is widespread in Atelopus, but rediscovery does not equal recovery, and many species are still likely living on the brink of extinction. The Atelopus rediscovery system may serve as an important tool for understanding amphibian population persistence under global change. (Kyle Jaynes)
Crinia signifera
Crinia signifera by Jodi Rowley
December 12, 2022: What signals breeding time for frogs? That’s traditionally been a challenging question to answer across large scales, but with the help of people all over Australia contributing to the national citizen science project FrogID, there’s now records of calling frogs every day of the year across the continent. This data allows a more comprehensive look at what is important for frogs at a broad scale when it comes to breeding. In a recent analysis, Thompson et al. 2022 used more than 150,000 frog records from 100 species to examine how environmental factors influenced frog calling over a three-year period. Combined with Bureau of Meteorology (BOM) weather data, they looked at a how cues (e.g., day-of year, daily temperature, recent trends in temperature, humidity, rainfall, and recent accumulation of rainfall) influence the calling behavior of these frog species at a macro-scale (10 km2 grid cells). They found a strong seasonal signal, with day of year the strongest relationship to calling in 67 out of 100 species, moderate relationships between temperature and calling, and weak relationships between rainfall and calling. In comparison. common narratives (i.e., explosive and prolonged breeders), they found that frogs did not group into distinct categories based upon the influence of meteorological factors. Knowing what cues are important to frog calling is vital for both planning when to look for frogs (for example, when monitoring a threatened population) and --after the surveys are done --interpreting what the results mean for that species, compared to historical records. (Maureen Thompson)
Plethodon cinereus
Plethodon cinereus by David Blackburn
December 5, 2022: Lungs have been independently lost in some members of all three major amphibian groups – salamanders, frogs, and caecilians. However, lungs have been lost in just one frog and one caecilian species. Lungs are absent in a larger number of salamander species, having been lost in 11 of 89 species of hynobiids and all 497 species of the family Plethodontidae. Lewis et al. (2022) confirm that plethodontids actually initiate lung generation early in their development but the process is reversed through programmed cell death (apoptosis) before they emerge from the egg. Remarkably, the authors show that many of the genes that are involved in lung development in species that keep their lungs are also expressed in the vestigial lungs of plethodontids. This finding suggests that early lung development may be a necessary feature for the development of other organs, such as the heart. Because all plethodontids lack lungs, they were most likely lost in the common ancestor of the group between 66 million years ago (the timing of the first divergence events within the plethodontid crown clade) and 110 million years ago (the timing of the split between Plethodontidae and its sister family, Amphiumidae), thus showing that the retention of the genetic program underpinning lung development have been maintained for tens of millions of years despite the early loss of lungs in the plethodontid common ancestor. (JM)
Rhinella marina
Rhinella marina by Andrew Snyder
November 28, 2022: The introduction history of cane toads to Australia is well documented; however, their introduction history in North America is unclear. Mittan-Moreau et al. (2022) sequenced Rhinella spp. populations across five introduced and five native populations to identify possible sources for North American introductions and the evolutionary consequences of introduction. They found the introduced Rhinella species in Florida is more closely related to Rhinella horribilis than to Rhinella marina (the source of all other known cane toad introductions). All introduced populations of toads had slightly lower genetic diversity than native populations, and showed genetic signals of population bottlenecks (sudden, rapid declines in population size) in their recent history. Nonetheless, introduced Florida populations showed less severe population declines (>500, at the lowest point) than had been reported by an oft-cited 1955 newspaper article describing an accidental release of just 100 toads. Lastly, genetic variants that may be under selection in introduced populations are largely present in native populations, suggesting that adaptation in the new, introduced environment may be enabled by genetic diversity already present in native populations. This study highlights the utility of genetic sequencing in understanding species introduction history, and the role of pre-existing genetic diversity in population persistence and expansion. (Cinnamon Mittan-Moreau)
Ambystoma barbouri
Ambystoma barbouri by Michael Graziano
November 21, 2022: Although complex parental care is proposed to contribute to the evolutionary success of vertebrates, the routes and role of parental care in vertebrate diversity are still contentious. A study by Vági et al (2022) uses 181 species representing the major lineages of salamanders and newts (Caudata) and finds that fertilization mode is tied to parental care where male-only care occurs in external fertilizers. Further, female-only care exclusively occurs in internal fertilizers. This suggests that internal fertilization is associated with the rise of terrestrial reproduction, since fertilized females are able to deposit their eggs on land, and with maternal care provision, the eggs could potentially develop outside the aquatic environment. Taken together, the results suggest that the diversity and follow-up radiation of terrestrial vertebrates are inherently associated with complex social parenting behavior. (VV)
Boana boans
Boana boans by Esteban Alzate
November 14, 2022: The pupil is the aperture of the eye, and its size and shape can have important consequences for vision. Most vertebrate pupils are large and round when dilated but can vary in shape and orientation when constricted. Amphibians exhibit extraordinary diversity in the shapes of their constricted pupils, but until recently the evolution of this trait had not been explored. Thomas et al. (2022) surveyed pupil shape from photographs in 1,294 species of frogs, salamanders, and caecilians. They found that pupil shape has high evolutionary lability, particularly among frogs, and is correlated with aspects of ecology. Species living aquatic and fossorial lifestyles typically have non-elongated pupils, while those in other habitats are more likely to have horizontally or vertically elongated pupils. Eye size also was correlated with pupil elongation, with larger eyes more likely to have elongated pupils. Finally, pupil shape varied across life stages: frog and salamander larvae typically have circular pupils that can remain circular or change to elongated pupil shapes after metamorphosis. AmphibiaWeb photos played a crucial role in this study, as well as another recent study on amphibian pupils from Cervino et al. (2021). (RBell)
Boana nigra
Boana nigra by Santiago Ron
November 7, 2022: AmphibiaWeb’s mission is to "connect people around the world by synthesizing and sharing information about amphibians to enable research, education, and conservation." In this vein, we have initiated a new effort- to summarize the existing, publicly available data on amphibians to document and provide a perspective on the state of amphibian research and knowledge between 2016 and 2020. In this issue of Ichthyology and Herpetology (Womack et al. 2022), we provide an overview of publishing trends, advances in conservation research, updates in systematics, trends in genomics, as well as compilations of data on acoustics, CT scans, traits, and online portals for amphibians. Among many of the resources assessed, we highlight that amphibians continue to be described at steady rates (150 species/year) with hotspots in northwestern South America, Madagascar, and Asia (e.g., species of the week Boana nigra was newly described from Ecuador in 2020). Moreover, although only 28 amphibian genomes were available at the time of writing this paper, genomic resources are rapidly expanding. Research trends suggest increasing interest in phylogenomics, microbiomes, and eDNA of amphibians, a stabilization in deep evolutionary relationships of amphibians, and the value of adaptive management strategies for amphibian conservation. We hope this review will be of use to the amphibiologist community, and we make a case for continuing to grow curated databases to facilitate access to and curation of amphibian data into the future. All data and scripts including exhaustive tables of new species descriptions, acoustic data, genomes, NCBI metadata, etc, all organized taxonomically, are available on our GitHub. If you have suggestions for future focal topics in our next State of the Amphibia publication, please let us know.
Myobatrachus gouldii
Myobatrachus gouldii by Ryan J. Ellis
October 31, 2022: Frogs have a unique spine that is shorter than most other tetrapods to provide axial rigidity for efficient jumping. Adler et al. (2022) measured the shape of the presacral vertebrae among more than 200 frog species to examine how the individual bones within the spine have evolved over the more than 200 million years of frog evolution. They discovered high evolutionary rates in the cervical vertebrae and in the more caudal trunk vertebrae but little evidence for selection pressures related to adult or larval ecology. However, they found body size was highly associated with vertebrae shape and microhabitat (especially burrowing) affected those allometric relationships. Their results differ from patterns of vertebrae evolution in other clades, such as mammals, and serve as a jumping-off point for studies of anuran vertebrae evolution and development. (MWomack)
Hemisus marmoratus
Hemisus marmoratus by Jörn Köhler
October 24, 2022: Changes to food webs can have unforeseen effects on other members of an ecosystem. Demare et al. (2022) documented how increased vegetation, presumably from the overhunting of large herbivorous mammals, changed the larval amphibian assemblage in tropical savannas in Comoé National Park, Ivory Coast (Côte d’Ivoire). Comparing surveys conducted before and after two civil wars, during which poaching caused vast reductions in large herbivorous mammals, the authors found significant increases in vegetation cover around ephemeral water bodies and a shift in dominant amphibian species in their larval form. The switch in amphibians favored species that use vegetation during breeding (Afrixalus spp., Hyperolius spp., and Hemisus marmoratus) and was detrimental to ground breeding species (Ptychadena spp.), which had previously been dominant. While increased vegetation likely provides more structure and food to aquatic systems, this shift was most closely correlated with the composition and structure of aquatic predators. It is unclear if this correlation is causal. However, this system provides a unique opportunity to better understand food web and ecosystem dynamics. (AChang)
Dendrobates tinctorius
Dendrobates tinctorius by John White
October 17, 2022: Early studies to identify chemicals in poisonous frogs from South America were hampered by the limited resolution of mass spectrometry tools in the 1970s. Skin extracts from several hundred frogs were needed for scientists to obtain enough of a single compound to reveal its chemical structure. Over the following 20 years, advances in the sensitivity of these tools revolutionized the ability to describe the chemical structure of compounds new to Western science using only tiny quantities. A new tool allows even more innovative research into the chemical biology of amphibians. Krieger et al (2022) report an adaptation of the MasSpec Pen that allows real-time quantification of alkaloids and metabolites on frog skin that does not require biopsies or euthanasia. The MasSpec Pen is a hand-held device that, when pressed onto amphibian skin for 10-15 seconds, dissolves skin secretions into a droplet of solution containing water and a small amount of ethanol. The pen then ports the sample through a tube into a mass spectrometry machine where compounds are ionized and researchers can determine their identities. Such a tool can be valuable in repeated sampling of the same individuals, and future adaptations of the tool could even allow real-time sampling in the field. (RDT)
Hyla orientalis
Hyla orientalis by Barbod Safaei Mahroo
October 10, 2022: In 1986, the Chernobyl (also spelled 'Chornobyl') nuclear accident in northern Ukraine released unprecedented amounts of radioactive material into the environment. Within the Chernobyl Exclusion Zone, Burrac and Orizaola (2022) surveyed the Eastern Tree Frog (Hyla orientalis) and found increased melanism compared with frogs just outside the Exclusion Zone. It is known that the dark melanin-based pigments could protect fungi against ionizing radiation but a protective role in melanism for vertebrates remains debated because of potentially high physiological costs associated with melanism. Burrac and Orizaola found no physiological costs associated with the maintenance of dark skin coloration in terms of frog body condition or oxidative status. Furthermore no short-term changes in coloration were detected, indicating that high levels of ionizing radiation, likely at the time of the accident, may have been selected for darker coloration in Chernobyl tree frogs. (MWomack)
Spea bombifrons
Spea bombifrons by Michael Graziano
October 3, 2022: Depending on environmental conditions, tadpoles of the Spea genus can switch from omnivores to predaceous carnivores that display cannibalism similar to post-metamorphic feeding behavior. The switch has long been attributed to heterochrony, or the developmental shift in the timing of gene-expression. However, Ledón-Rettig (2021) tested this hypothesis against an alternative that a novel pattern of gene expression is behind the ecological behavioral shift. She quantified RNA expression in two morphotypes of Spea bombifrons at two points in their development, tadpole and juvenile, and found that gene expression of tadpoles were more similar to each other than the gene expression of juveniles, which were also more similar to each other than to tadpoles. However, predaceous tadpoles also expressed a different suite of genes than omnivorous tadpoles lending support to the alternative hypothesis of a novel pattern of gene expression. These findings do not discount a role for heterochrony, but provide evidence of the potential for multiple routes to novel behaviors. (AChang)
Eleutherodactylus coqui
Eleutherodactylus coqui by Chris Brown
September 26, 2022: The global pet trade and transport networks have accelerated the number of introduced amphibian and reptile species worldwide, some becoming invasive problems and have caused extirpation or declines of native species and disruptions of ecosystems. Furthermore, these invasions impact socio-economies (i.e., monetary and social impacts) and human health (i.e., spread of disease). In a first attempt to quantify the financial costs, Soto et al (2022) analyzed the global economic costs caused by invasive alien herpetofauna using a dataset of 21 herpetofauna species, six amphibian and 15 reptile invasive species. They showed the cost of invasive species generally increased over time but peaked between 2011 and 2015 for amphibians and 2006 to 2010 for reptiles. Invasive herpetofauna cost approximately a total of 17.0 billion US$ between 1986 and 2020 and was predominantly associated with the American bullfrog (Rana catesbeiana) and brown tree snake (Boiga irregularis), with 6.0 and 10.3 billion US$ in costs, respectively. Geographically, Oceania and Pacific Islands recorded 63% of total costs, followed by Europe (35%) and North America (2%). The sector most affected by amphibians was authorities-stakeholders through post-invasion species management (> 99%), while for reptiles, impacts were reported mostly through damages to mixed sectors (65%). The results from this study might suggest research biases towards well-known taxa; however, it highlights the importance of synthesizing the cost of herpetofauna invasion to provide a better framework for regulatory policies and investment in control or biosecurity measures (e.g., trade of alien pets). (Umilaela Arifin)
Mantella aurantiaca
Mantella aurantiaca by Jake Hutton
September 19, 2022: Male frogs vocalize for several reasons: defense of territories, sexual selection (such as male-male competition, female mate choice), and can provide information about the male's physical condition. Thus, the ability of a male or female frog to recognize calls of its own species is important to the survival of populations. To test recognition of a call, researchers can use phonotaxis experiments, in which the movement responses of individuals to the male call are recorded and analyzed. Passos et al. (2022) studied the phonotactic responses of wild and captive (zoo-reared) male Golden Mantella frogs (Mantella aurantiaca) to both wild and captive playback calls of the same species to determine the impact of captivity on phonotactic behavior. They found that wild males had a similar response to calls from wild and captive males whereas captive males had a significantly stronger response to calls of captive conspecifics. They conclude that lack of appropriate response by captive frogs to the calls of wild conspecifics could have negative consequences for conservation efforts if captive-reared frogs were released to the wild. Although male-male interactions are important in mating, it remains unknown how captive females respond to wild vs captive calls. Their response would likely be more relevant to successful reproduction. (DCC)
Pelobates cultripes
Pelobates cultripes by Arlo Hinckley
September 12, 2022: The ability to adjust how an organism looks, functions, and behaves based on their environment (i.e., change phenotypes) within a lifetime is termed plasticity. Although being able to adjust to environmental changes seems incredibly beneficial, not all organisms have the same capacity to do so. It is hypothesized that plasticity might have underlying costs, and thus unfavorable in reliable environments where the costs to plasticity outweigh the benefits. However, the proposed costs to plasticity are mostly theoretical and difficult to measure. A study by Burraco et al. (2022) took advantage of the developmental plasticity within Iberian Spadefoot Toads (Pelobates cultripes) to identify these costs. Spadefoot tadpoles often alter their growth and morphology when raised with predator cues, and the degree of plasticity is variable among individuals. They tested spadefoot sibling pairs raised with and without predator cues, and asked whether plasticity was associated with a cost, specifically either oxidative stress or immune suppression. They showed tadpoles with a higher degree of plasticity were associated with enhanced metabolism (denoted by higher activity of antioxidant enzymes) as well as immune and oxidative costs. This is a rare study to attempt to identify the underlying costs of plasticity and amphibians provide a number of great systems for addressing this outstanding biological question. (MWomack)
Rana catesbeiana
Rana catesbeiana by Adam G. Clause
September 5, 2022: The American bullfrog (Rana catesbeiana) has become a globally-important invasive species over the last century, wreaking destructive impacts on the ecosystems and economies of places it invades. Though bullfrogs are native to the eastern United States, one of their invasive ranges is the western U.S., where they likely face higher pressure from Batrachochytrium dendrobatidis (Bd), a devastating pathogen of amphibians that they generally tolerate and may be responsible for spreading. LaFond et al (2022) sampled bullfrogs across the U.S. to address an important paradox in invasion biology: species invasions are frequently characterized by strong losses of genetic diversity, yet these species still adapt to diversity of new conditions. They identified the invasion as having originated from one population in the Midwest, with a possibly secondary source in the northwest, and found that the invasive population was characterized by significant losses in mitochondrial genetic diversity. Invader bullfrogs had higher Bd infection prevalence and intensity. However, balancing selection was clearly at work, resulting in invader bullfrogs maintaining diversity at the MHC locus, known to be involved in immunocompetency against Bd in other amphibians. They also found evidence for positive selection on four MHC residues involved in pathogen recognition. Perhaps focusing on adaptive loci, which should better predict evolutionary potential, will help us resolve the genetic paradox of invasion! (ESteigerwald)
Litoria peronii
Litoria peronii by Gracie Liu
August 29, 2022: Cities, suburban gardens, and other human modified areas are drastically different from frogs’ natural habitats. They are often warmer, noisier, artificially brighter, and more polluted. Gathering the data needed to understand whether frogs are adapting their behaviours to cope with these conditions is challenging, but increasingly, citizen science data is allowing us to investigate large-scale ecological questions like this. Liu et al. (2022) analysed over 226,000 frog records from across Australia to examine whether human-driven habitat modification influences the breeding phenology or call characteristics of frogs. They found that frog breeding seasons began earlier and were almost 3 weeks longer in areas that were highly modified by humans. However, habitat modification did not affect frog call characteristics. Their results suggest that human-induced phenological changes could be widespread among frogs, with largely unknown ecological consequences. This research also highlights the incredible value of citizen science data in better understanding amphibians in a changing world. (Gracie Liu)
Finite Element Analysis (FEA) of frog forelimb
Finite Element Analysis (FEA) of frog forelimb (modified from Keeffe and Blackburn 2022)
August 22, 2022: Why do frogs have such strange skeletons? Unlike humans, many bones of the frog skeleton are fused together. For example, fusion between the radius and ulna bones of the forelimb are thought to reinforce the arm during landing. However, many frogs do not jump or do not use the arms to land. This raises the question of why those species still have a fused radius and ulna. Keeffe and Blackburn (2022) used a computer modelling technique called finite element analysis (FEA) to test how the degree of fusion in the radioulna impacts stress during different behaviors. Their results suggest that fusion of these bones is optimized to minimize stress across different loading scenarios while also minimizing volume. Further, other behaviors such as amplexus may maintain fusion of the radioluna in frogs that do not use the forelimb for jumping. (DBlackburn)
Figure in first column shows the four normal morphologies of the radioulna; the middle column shows the filled versions of the models to their left; the right column shows the three cylindrical, geometrically symmetrical models. The brighter color shows areas of higher stress.
Rhacophorus nigropalmatus
Rhacophorus nigropalmatus by Peter Janzen
August 15, 2022: Carotenoids are pigments produced primarily by plants. Animals ingest carotenoids to use in a variety of important ways, especially in producing or modifying coloration. For example in birds, they are the basis of the red pigmentation in the plumage of breeding male house finches and crossbills. Stückler et al. (2022) investigated the role of carotenoids in modulating coloration in Wallace's Flying Frog, Rhacophorus nigropalmatus. This frog exhibits a dramatic ontogenetic shift in coloration from bright red in recently metamorphosed juveniles, to green and brown with extensive white spotting in older juveniles, to vivid green with black and yellow webbing and yellow flanks in adults. In controlled experiments, they showed that dietary carotenoid supplementation was necessary for this species to achieve its natural vivid green adult coloration. Individuals without a source of dietary carotenoids, or reduced carotenoid intake, were blue-green in color. Furthermore, R. nigropalmatus was capable of extensive rapid color changes associated with either the stress of handling or the light regime experienced by the individual frog – but only if they had sufficient carotenoids in the diet. This study broke a lot of new ground, including that the dull adult pigmentation resulting from lack of sufficient carotenoids in early life is apparently not correctible later in life with enhanced carotenoid intake. Given the likely importance of baseline coloration and dynamic color change for crypsis and sexual selection, dietary carotenoids are likely critical to R. nigropalmatus – and this likely applies to many additional species of frogs as well. (JM)
Dermatonotus muelleri
Dermatonotus muelleri by Arturo Munoz
August 8, 2022: Studies of reproduction associated with skin glands among frogs are rare. However, work by Antoniezi et al. (2022) on Mueller’s Termite Frog (Dermatonotus muelleri) – a Brazilian microhylid known for its toxic skin secretion – showed that this species possesses poison glands that are uncommon among frogs: they are very large, elongated, one juxtaposed to the other, and occupying a considerable part of the dermal volume. The authors further showed that in males, adhesive glands were observed in the dorsum of the forefoot, ventral forearm, as well as the pectoral and anterior ventral regions. The disposition of such glands seems to compensate for the round and short forelimbs of Dermatonotus muelleri during amplexus through an axillary embrace. Their work contributes to our knowledge of skin gland diversity especially with respect to reproduction. (Umilaela Arifin)
Gyrinophilus subterraneus
Gyrinophilus subterraneus by Danté B Fenolio
August 1, 2022: Cave species are often highly endemic and can be especially vulnerable to habitat degradation within and surrounding the cave systems they inhabit. The West Virginia Spring Salamander (Gyrinophilus subterraneus) is only known from a single cave and though it is phenotypically distinct from the more widespread Spring Salamander species complex (Gyrinophilus porphyriticus), its evolutionary history and status as a unique species have been debated for decades. Grant et al. (2022) combine genomic and morphological data to demonstrate that G. subterraneus represent a distinct lineage, and that they occur in sympatry with G. porphyriticus within General Davis Cave. Surprisingly, the team also reports hybridization within the cave with evidence of partial reproductive isolation between the species. Collectively, the results provide strong support for continuing to recognize G. subterraenus as a distinct and unique species, and reveal a compelling study system for understanding how salamanders adapt to cave ecosystems. (RBell)
Brachycephalus pernix
Brachycephalus pernix by Richard L. EssnerJr. et al 2022
July 25, 2022: Frogs are famous for being accomplished leapers. In addition to their take-off, nearly all frogs control their trajectory through the air and the eventual landing. However, Essner et al. (2022) found that this is not true for the tiniest of frogs where size limitations have performance consequences. They demonstrate the small pumpkin toadlets (genus Brachycephalus) from Brazil do not control their posture after take-off, resulting in sometimes wildly uncontrolled landings. The authors hypothesize that the extremely tiny semicircular canals— the smallest yet recorded for an adult vertebrate— result in low sensitivity making it difficult for the frogs to sense their position as they move through the air. (DCB)
Duttaphrynus melanostictus
Duttaphrynus melanostictus by Lars Fehlandt
July 18, 2022: Amphibians are generally considered saltwater intolerant, although many amphibian species are found in coastal areas. How will climate changes such as increasing temperature, sea levels, and storm surge events impact amphibian survival? Using three coastal frog species (Duttaphrynus melanostictus, Fejervarya limnocharis and Microhyla fissipes), Chuang et al. (2022) tested the effects of salinity on both tadpole survival and the ability to withstand high temperatures (critical thermal maxima or CTmax). They found in all species exposure to high salinity treatments lowered survival, the maximum temperature that tadpoles could withstand, and development rate. Their study shows that rising temperatures and increased salinity exposure might be a double whammy for tadpoles. This study highlights the importance of including and measuring multiple stressors in climate changes studies because environments are predicted to change in multiple ways that can have compounding effects on organisms. (MWomack)
Atelopus zeteki
Atelopus zeteki by John White
July 11, 2022: Amphibian skin is a dynamic ecosystem of interacting microbes, pathogens, and host-secreted compounds. Amphibians secrete many peptides through their skin, some of which are antimicrobial and have been linked to protection against the fungal pathogen that causes chytridiomycosis, Batrachochytrium dendrobatidis (Bd). However, not all peptides are antimicrobial, and some could even provide a more favorable environment for pathogen growth. For example, Gass and Voyles (2022) found that when the Bd-susceptible Atelopus zeteki were experimentally infected with Bd, individuals that had their peptides depleted survived longer than individuals who did not have their skin peptides depleted. Also, Bd growth in plates was higher in treatments with A. zeteki skin secretions than in control treatments. Their study highlights how the relationship between skin secretions and pathogens can be very different depending on the host species, and that some secreted peptides may even enhance pathogen growth. (AByrne)
Taricha granulosa
Taricha granulosa by Aaron Schusteff
July 4, 2022: The co-evolutionary phenomenon where prey defense and the predator's ability to evade the defense escalate over time through reciprocal natural selection is often called an evolutionary 'arms race'. One textbook example is that of the tetrodotoxin-defended newts (Taricha sp.) and their tetrodotoxin-resistant garter snake predators (Thamnophis sp.). However, recent discoveries that bacteria on Taricha skin can produce tetrodotoxin (TTX) (Vaelli et al. 2020) and that the toxicity of individual newts varies over time (Bucciarelli et al. 2016) complicates the application of an arms-race model to these taxa. In a review of arms races between toxic animals and resistant predators, Bucciarelli et al. (2022) revisit the Taricha-Thamnophis ecosystem and propose a new model incorporating a potential role for skin bacteria and inducible variation in TTX defenses. Their study provides a new perspective that is likely to generate further research and discussion on the widely known newt - garter snake study system. (RDT)
Adelphobates galactonotus
Adelphobates galactonotus by Fábio Maffei
June 27, 2022: While many poisonous animals and nearly all venomous animals use biosynthesis to produce their own toxins, poison frogs of the family Dendrobatidae obtain and accumulate alkaloids from their diet. Since this discovery, researchers have wondered whether poison frogs passively accumulate the toxins that they consume or whether they can regulate how toxins are taken up. Jeckel et al (2022) demonstrate that Adelphobates galactonotus accumulate two kinds of alkaloids, histrionicotoxin (HTX 235A) and decahydroquinoline (DHQ), with differing efficiencies. They also show that frogs improve the accumulation efficiency of HTX 235A when consumed in low doses, and that the frogs modify the chemical structure of DHQ, two mechanisms that had not been previously reported. Their study provides an important baseline for future studies of toxin accumulation in poison frogs and other animals with acquired chemical defenses. (RDT)
Aneides vagrans
Aneides vagrans by Christian Brown
June 20, 2022: Many amphibians are known to be arboreal, living in trees. Controlled aerial descent by parachuting (i.e., manipulating falling speed) or gliding (i.e., generating a horizontal component of locomotion while descending) is common among arboreal animals, yet until recently, had been unexplored in salamanders. Brown et al. (2022) documented controlled aerial descent in the highly arboreal Aneides vagrans, which lives in the canopies of the tallest trees on Earth, as well as in three other related species representing a continuum of arboreality: A. lugubris (most arboreal after A. vagrans), A. flavipunctatus, and Ensatina eschscholtzii (least arboreal). The authors used a vertical wind tunnel to simulate aerial descent and motion capture techniques to characterize their behaviors. The more arboreal species (A. lugubris and A. vagrans) regularly demonstrated aerial control by adjusting body orientation, parachuting, and gliding. Alternatively, A. flavipunctatus and E. eschscholtzii rarely showed such control. This is the first instance in which salamanders have been demonstrated to perform such behaviors, which they do without specialized aerodynamic control surfaces like skin flaps. It is possible that the morphological features typically associated with arboreality, such as relatively flattened body, long limbs and digits, and large feet relative to body size, serve to enhance aerial control. Further investigation into such inconspicuous aerodynamic features may reveal similar adaptations in other arboreal taxa. (Erik Sathe)
Dendrobates leucomelas
Dendrobates leucomelas by Jessica Nelson
June 13, 2022: Color and pattern phenotypes in amphibians are often ecologically important. A well known example is the role of bright warning colors advertising toxicity in poison frogs of the genus Dendrobates. In a new study, Yuan et al. (2022) highlight an underappreciated axis of color pattern diversity in three species of Dendrobates (D. auratus, leucomelas, tinctorius): age-related, within individual variation. Using a long-term longitudinal study of frogs at the National Aquarium, they show that the relative area of bright color decreases and melanization increases with age in Dendrobates poison frogs. Their results set the stage for future studies to investigate the mechanism by which melanization increases with age and the ecological consequences of color pattern change in these conspicuous frogs. (Michael Yuan)
Rana catesbeiana
Rana catesbeiana by John Blenis
June 6, 2022: The global panzootic lineage of the amphibian chytrid fungus (Bd-GPL) has triggered some of the worst disease-related wildlife declines ever documented. However, in some areas of the world, such as the eastern United States, Bd-GPL is widespread but has not caused amphibian die-offs. Byrne et al. (2022) revealed a previously unknown association between Bd-GPL lineages and their host species. Specifically, they found that bullfrogs in both their native range (e.g., Pennsylvania) and in their introduced range (e.g., Nevada) carry a specific lineage of Bd-GPL while other amphibians in the same locations are often infected with a different pathogen lineage. This intriguing relationship may be due to a long history of Bd in the eastern US which could have allowed host and pathogen to coevolve. (AByrne)
Odontobatrachus natator
Odontobatrachus natator by Mark-Oliver Rödel
May 30, 2022: In most frogs, adults are considered to be primarily carnivorous with only a few species known to consume non-animal matter regularly. Schäfer et al. (2022) thoroughly investigated plant ingestion in all five species of the West African frog genus Odontobatrachus and two similar sized, sympatric species. The authors convincingly demonstrate that Odontobatrachus species are deliberately eating the leaves of the riparian tree Parkia bicolor through a combination of stomach-flushing hundreds of frogs across populations and seasons, a detailed capture-mark-recapture study, and a feeding experiment. Despite consuming large quantities of this particular leaflet, however, it does not appear that the frogs digest this plant material, and thus it is unclear why they are eating it. Overall, this study provides important insights into the diets of a unique frog radiation and highlights exciting areas for future research to better understand plant ingestion in this unusual group. (RBell)
Rana temporaria
Rana temporaria by Martin Pickersgill
May 23, 2022: Habitat loss or modification is the biggest threat to amphibians, which includes the introduction of non-native plants. Eucalyptus globulus trees have been introduced globally from its native Australia, and its negative effects on native species, including adult amphibians, have been documented. What about other stages? Iglesias-Carrasco et al. (2022) investigated with experiments on the effects of eucalypt leachates on tadpole behavior, morphology, growth, and immune response. Rana temporaria, Alytes obstetricans, and Pelophylax perezi tadpoles were raised in mesocosms with either native oak or exotic eucalypt leachates then exposed to predator cues. The authors found that while anti-predator responses were not significantly affected, tadpoles raised in eucalypt leachates were smaller and had weaker immune responses. Furthermore, the morphology of P. perezi tadpoles in eucalypt treatments were similar to the stress morphology of other species, which may affect the tadpoles’ ability to escape predators and jump in later development. Although species varied in responses, these results indicate that the poor nutrient content and high toxicity of Eucalyptus have strong impacts at critical early stages of frog development. Further studies are needed to fully understand the long-term fitness consequences of Eucalyptus monocultures. (AChang)
David Wake
David Wake in Acultzingo, Veracruz, Mexico, 2003, by James Hanken
May 16, 2022: On May 7th, Dr. Marvalee Wake and the Museum of Vertebrate Zoology hosted a Celebration of Life for David Wake at UC Berkeley, which featured a slate of speakers on the academic and personal life and career of Dr. David Wake, the founder of AmphibiaWeb. Attendees came from all over the US, Mexico, and Europe, with well-wishers from around the world. A universal theme from the day of celebration was the generosity of spirit he afforded every one he interacted with and the intellectual breadth and depth that he commanded in the fields of evolutionary biology, systematics, development, and herpetology as well as inspiring insights in the philosophy of science. David was deeply concerned with the challenges that we face as humans continue to alter our planet, in particular he was one of the first scientists to speak out about the global amphibian crisis in the late 1980’s. Dave helped galvanize a global network of concerned scientists chairing the first Declining Amphibian Populations Task Force (DAPTF); these efforts eventually led to the formation of AmphibiaWeb. Coming soon, photos, transcripts and other material from the personal recollections of his students, colleagues and friends on the work and impact of our friend and mentor, both here on AmphibiaWeb and on Dave’s personal website (
Aplastodiscus leucopygius
Aplastodiscus leucopygius by Anat Belasen
May 9, 2022: Habitat fragmentation and infectious diseases are two of the biggest global threats to amphibians, but how do these two threats interact? Besides leading to stress and local extirpations in vulnerable wildlife populations, habitat fragmentation can reduce genetic diversity, which in turn may increase susceptibility to disease. Belasen et al. (2022) evaluated relationships between habitat fragmentation, genetic diversity, and disease susceptibility in six frog species endemic to Brazil’s Atlantic Forest, an amphibian diversity hotspot. They specifically tested whether habitat fragmentation reduces diversity in a genetic region related to immune function (MHC IIB), which is associated with amphibian susceptibility to the pathogen Batrachochytrium dendrobatidis (Bd). They found that habitat fragmentation was associated with genetic erosion at MHC IIB across species, and individuals that were MHC IIB heterozygotes (“hybrids”) experienced reduced Bd infection risk. The most severe genetic erosion at MHC IIB occurred in forest specialist frogs including Aplastodiscus leucopygius. Forest specialist frogs also exhibited increased Bd infections (higher prevalence and loads) in fragmented habitats. Overall their results showed that habitat fragmentation impacts MHC IIB diversity and potential disease susceptibility in frogs, with the greatest impacts in sensitive forest specialists. (Anat M Belasen)
Hynobius retardatus
Hynobius retardatus by Henk Wallays
May 2, 2022: Paedomorphosis, the retention of juvenile characteristics into adulthood, is well known in salamanders. In salamanders, paedomorphosis occurs via neoteny, the truncation of somatic development even as the gonads become mature. Extreme paedomorphic (obligatorily neotenic) forms typically look like larva and never transform, remaining aquatic throughout their lives. Perhaps the most famous of neotenic salamanders is the critically endangered Axolotl (Ambystoma mexicanum), known only from Lakes Xochimilco and Chalco in Central Mexico. This species has become an important model organism for developmental biology and is widely available in the pet trade, and thus has been distributed around the world. In Japan, the axolotl goes by the humorous name "Wooper Looper", ascribed to the species from a 1985 TV commercial that caught the fancy of the public. There is even a Wooper Looper Pokémon. Now Japan has its own Wooper Looper– a facultatively neotenic hynobiid salamander (the Ezo salamander, Hynobius retardatus). In this species, most individuals transform into terrestrial adults, but they are developmentally flexible and sometimes remain in the water, failing to transform while nevertheless achieving reproductive maturity. Neotenic adults were first collected in 1924 and observed again in 1932 in Lake Kuttara in Hokkaido, but neotenic adults were not seen again until Dr. Hisanori Okamiya rediscovered the phenomenon in the form of three specimens collected in a pond in south Hokkaido in December 2020 and April 2021 (Okamiya et al. 2021). Hynobius retardatus and Batrachuperus londongensis are the only hynobiid species (out of 87 total) that exhibit facultative neoteny. (JMcGuire)
Dendropsophus leucophyllatus
Dendropsophus leucophyllatus by Christian Cox
April 25, 2022: Frogs and toads have large, prominent eyes and many visually-guided behaviors, making them an exciting group in which to study the evolution of vision. Some frogs, such as the Clown Tree Frog, Dendropsophus leucophyllatus, have spectral filters in the lenses of their eyes that block short wavelengths of light (e.g., UV), with important implications for how they see in low light and the resolution of their vision. Thomas et al. (2022) measured the spectral transmission of light through the ocular lenses of 85 species of frogs and salamanders and tested whether shortwave filtering was associated with ecology. They found that day-active frogs more commonly evolve lenses that filter out shortwave light, which should protect the retinas of diurnal species from damage and improve visual acuity in bright environments. Night-active species usually had more transparent lenses, likely to maximize sensitivity in dim light. However, despite being mostly nocturnal, scansorial species that typically climb up into plants show selection for stronger shortwave filtering in their lenses than species that tend to be found on the ground or in water. Climbing frogs may sacrifice sensitivity for resolution to navigate their complex arboreal environments. (Katie Thomas)
Boana semilineata
Boana semilineata by Dr. Peter Janzen
April 18, 2022: Frogs are well known for their complex life cycles, with many species having a free-swimming tadpole stage before metamorphosing into a froglet that often lives a more land-loving lifestyle. This great diversity in form and ecology of tadpoles parallels the amazing diversity of adult frogs but has received far less attention. In a tremendous effort to bridge this gap between tadpole and adult data availability, Pezzuti et al. (2021) have collected life history and morphological data for 67 species belonging to 25 different genera and 11 families. This study also includes the first tadpole descriptions for seven species! Aside from the wealth of data for future research, including illustrations, photographs, and identification keys, this study provides an important benchmark for frog conservation in the Brazilian Iron Quadrangle (IQ, Quadrilátero Ferrífero), a region of high amphibian diversity and ongoing habitat destruction from the heavy mining activities. Tadpole habitats are as threatened as adult frog habitats and it is impossible to monitor and conserve frog species if we do not understand tadpole diversity. (MWomack)
Rana boylii
Rana boylii by William Flaxington
April 11, 2022: Amphibians dwelling in Mediterranean climates are adapted to hot, dry summers and cool, wet winters, but climate change is intensifying the cycle of droughts and floods in these habitats. How do riverine frogs persist when surface flow becomes intermittent? Kupferberg et al. (2021) investigated this by mapping frog distribution in habitat mosaics created by seasonal drying of stream channels in two San Francisco Bay Area watersheds (California, USA). They monitored populations of the Foothill Yellow-legged Frog (Rana boylii), an imperiled species indigenous to rivers and streams of California and Oregon, and found that although water may not last long enough after spring egg-laying for tadpoles to reach metamorphosis during droughts, the drying appears to allow co-existence with the invasive North American Bullfrog (Rana (Aquarana) catesbeiana). Bullfrogs can tolerate the fungal disease, chytridiomycosis, while Rana boylii is vulnerable to its lethal effects. In the autumn when frogs concentrate at remnant pools and cold snaps occur, conditions are ripe for transmission of pathogens and juvenile frogs succumb to disease. Despite local die-offs and episodes of poor recruitment, more than two decades of monitoring revealed that R. boylii populations can rebound after wetter winters that create sufficiently long hydroperiods for tadpoles to reach metamorphosis. (Sarah Kupferberg)
Leptodactylus fragilis
Leptodactylus fragilis by Vladlen Henriquez
April 4, 2022: The evolutionary transition to terrestriality and terrestrial breeding in amphibians has occurred repeatedly, but have the required key adaptations, e.g., resistance to desiccation and toxic ammonia build-up, likewise been repeated? Méndez-Narváez and Warkentin (2022) examined this question in a comparative study of four frog lineages, contrasting either short (Agalychnis callidryas, Engystomops pustulosus) or long (Hyalinobatrachium fleischmanni, Leptodactylus fragilis) larval exposure to desiccating conditions. They carried out experiments in an open lab in the rainforests of Gamboa, Panama (Smithsonian Tropical Research Institution). By manipulating environmental conditions (wet vs. dry) and tracking levels of ammonia and urea excretion, they evaluated the tolerance to ammonia exhibited by larvae of each species. They found the two species (H. fleischmanni, L. fragilis) which experience the highest risk of desiccation showed clear evidence for urea production and for pronounced increases in urea excretion, whereas the other two did not. Without urea excretion, the larvae of the high-risk species could experience lethal conditions, providing a clear case for the adaptive value of urea production in these species. They also compared the two foam-nesting species (E. pustulosus, L. fragilis) and two leaf-breeding species (H. fleischmanni, A. callidryas), demonstrating the similar changes in nitrogen metabolism in response to desiccation risk in both comparisons. Their study provides important evidence for the potentially key role of adaptive plasticity in mediating major evolutionary changes. (KSummers)
Pseudacris regilla
Pseudacris regilla by Maria Delia Basanta
March 28, 2022: The amphibian skin microbiome plays an important role in protecting its hosts against pathogens such as Batrachochytrium dendrobatidis (Bd), one of the causative agents of chytridiomycosis. Bd is comprised of multiple genetic lineages that may exhibit differences in their ability to cause disease. Basanta et al. (2021) investigated if differences in Bd genetic variation are linked to differences in the amphibian skin microbiome. They studied associations between Bd infection load, Bd genetic diversity, and skin bacterial communities in populations of the Pacific Chorus Frog (Pseudacris regilla) of Baja California, Mexico. They found that Bd isolates have genetic spatial structure, and the Bd genetic differences and infection load are correlated with the skin bacterial community composition of P. regilla. Their results indicate that skin-associated bacteria and Bd strains likely interact on the host skin, highlighting this key microbial interaction as an important factor in shaping amphibian-Bd disease dynamics. (AByrne and MD Basanta)
Colostethus imbricolus
Colostethus imbricolus by Pablo Palacios-Rodríguez
March 21, 2022: Sexual dichromatism is the difference in color between males and females of the same species, and has been seen in several families of frogs. Palacios‑Rodríguez et al. (2022) explored the reproductive success of this phenomenon in Colostethus imbricolus, a cryptic poison dart frog that exhibits parental care. Unlike other dendrobatid frogs, tadpole transport in this species is predominantly performed by females, with more conspicuously patterned females transporting more tadpoles. In this instance of a sex-role reversal, the authors posit that males are assessing female fitness based on their coloration and that conspicous female coloration may serve as an aposematic signal for visual predators. This conspicuous coloration also is unique in that unlike other conspicuous females, C. imbricolus is not territorial. These findings highlight the varied reproductive strategies of amphibians and the complex evolutionary interactions of coloration, sexual selection, and antipredator strategies. (AChang)
Rana sylvatica
Rana sylvatica by John White
March 14, 2022: One of the silverlinings of the COVID-19 pandemic has been reduced human activities on the landscape (sometimes called the "anthropause"), notably a decrease in motor vehicle traffic during lockdown. This provided a unique opportunity while monitoring amphibians in northeastern United States. Using a community citizen science project, The Maine Big Night: Amphibian Migration Monitoring, Leclair et al. (2021) collected data on migrating amphibians crossing roads at sites throughout Maine during amphibian mating seasons, from March to May in 2018 through 2021. Almost 8,000 amphibians representing 16 species were recorded at 199 sites surveyed during these four years. They found a 50% decrease in frog mortality in 2020 compared to the other survey years, mainly due to decreased frog deaths in March and April. Wildlife collision data for other species in Maine (e.g., deer, turkeys, moose) were consistent with this trend of lower wildlife mortality in spring 2020. Thus, there was a significant reduction in frog deaths in Maine because of the traffic reductions during the COVID-19 lockdown. In the same time period, increasing precipitation correlated with increasing frog deaths, but not in salamanders, suggesting that environmental factors influence frog and salamander movements differently. Roads can be significant barriers to amphibian migrations; thus, even small changes can have large effects for these populations, especially for frogs. (CS)
Plectrohyla hartwegi
Plectrohyla hartwegi by Joachim Nerz
March 7, 2022: Plethodontid salamanders have long been known to use "vaccination" as part of their mating behavior. Unlike the familiar form of vaccination in which antigens are introduced into the circulatory system to induce an immune response, the term vaccination in plethodontid salamanders refers to the male using his teeth to scratch the back of a female during courtship, thereby introducing pheromones from his mental gland directly into her blood stream. These pheromones are known to enhance female receptivity. Such mechanisms of so-called "traumatic mating" are common among arthropods, but rare in vertebrates. Now, Schulte et al. (2021) suggest that a similar mechanism may be at play in several species of frogs in the genus Plectrohyla (Hylidae). Intrigued by the elongated teeth and swollen lips of reproductively active males – males which are known to scratch the female’s back with those teeth during amplexus – they showed via microscopy that the swollen lips house specialized breeding glands. Using transcriptome sequencing, Schulte et al. discovered the glands produce sodefrin precursor-like factors, which are known to have pheromone function in other amphibian species. Although additional research will be required to confirm the role of vaccination in Plectrohyla, this study showcases the myriad (and sometime bizarre) lengths that males will go in their effort to enhance mating success. (JM)
Atelopus certus
Atelopus certus by Brian Freiermuth
February 28, 2022: Harlequin toads (Atelopus) are renowned for their toxicity, but how much is really known about their chemical defense strategies and characteristics? Pearson and Tarvin (2022) review Atelopus chemical defense literature and find that only 16 of the 100 known species have been assessed for toxins. Furthermore, South American species – which make up the vast majority of Atelopus diversity – have received disproportionately little investigation relative to Central American species. Surveyed Atelopus possess individual toxins (chiriquitoxin and zetekitoxin) and toxin combinations found nowhere else in nature, and the authors suggest that the genus contains further unidentified toxin diversity that – in the face of catastrophic population declines – may be lost to science. The authors also trace the development of toxin detection and quantification methods applied to Atelopus, noting impacts of historical methodological limitations on chemical defense data and identifying promising techniques for future studies. Lastly, given the limited information available regarding Atelopus predators, they speculate about possible immunological and ecological roles of Atelopus toxins. Time to study many harlequin toad species may be limited, but Pearson and Tarvin make the case for continued chemical defense research on this genus. (Kannon Pearson)
Rana temporaria
Rana temporaria by Andreas Nöllert & Christel Nöllert
February 21, 2022: How will increasing temperatures from the climate crisis impact amphibian aging and mortality? Despite its relevance to conservation, little data exists on the relationship between temperature and senescence in free-living animals. Cayuela et al. (2021) studied pairs of frogs from two families divided by 100 million years of evolutionary history to answer this: Rana luteiventris and R. temporaria (Ranidae) and Anaxyrus boreas and Bufo bufo (Bufonidae). The North American toads and frogs represented sampling along a climatic gradient, whereas the European species represented sampling from climatically contrasted sites. They found that actuarial senescence rates— i.e., the rate at which mortality increases with age— increased with the mean annual temperature experienced in all species. In all species but Anaxyrus boreas, increasing temperatures corresponded to decreasing lifespans. These relationships are presumably attributed to amphibians' increasing pace of life with increasing temperatures; they are active for longer periods, have a higher metabolism, lower mitochondrial efficiency, and accumulate oxidative damage more rapidly. The impacts of increasing temperature on these frogs might be exacerbated by increasing evaporative water loss and influenced by genes involved in adapting amphibians to warmer conditions. In the ranids studied, the authors found increasing temperatures flipped sex differences in senescence rate in R. luteiventris but not R. temporaria. These results paint a grim picture for amphibians as global temperatures increase. Amphibian aging is expected to accelerate, with potential skewing sex ratios in some species. (ESteigerwald)
Bufotes viridis
Bufotes viridis by Joachim Nerz
February 14, 2022: Reproductive isolation is instrumental in speciation, but it remains largely enigmatic how many incompatibilities are required to prevent hybridization and where they lie across the genome. By studying patterns of admixture in amphibian hybrid zones, Dufresnes et al (2021) found that reproductive isolation is initiated by numerous small-effect incompatibilities scattered across the genome rather than concentrated in a few important genes. Unlike mammals and birds, in which Y/W degeneracy is a major cause of hybrid dysfunctions, the undifferentiated sex chromosomes of amphibians do not always host more genetic incompatibilities than other chromosomes. This may explain why amphibian speciation is relatively slow, and its clock-like dynamics offer practical perspectives to categorize evolutionary lineages into species or subspecies. (VV)
Hyalinobatrachium valerioi
Hyalinobatrachium valerioi by Dennis Kollarits
February 7, 2022: Many types of predators assault frogs; an unusual group of micropredators are frog-biting midges (Diptera: Corethrellidae). These tiny flies home in on calling frogs from which they get a blood-meal. Although corethrellids have been studied in the context of their predation on single species, the broader interactions among predators and prey have not generally been examined. For example, does a midge species attack only a single frog species, and how many midge species are in a community? Virgo et al. (2021) examined a midge-frog community of 17 frog species in Costa Rica and found that although a single midge species may attack a variety of frog species, there is some degree of specialization, and certain frog species were targeted much more frequently. Although five different morphospecies of corethrellids were identified, DNA analysis detected several, up to 20, cryptic species. When the DNA-delimited candidate species were used as units instead of the morphospecies, the specificity of the mite-frog interactions increased. Much remains to be investigated in this fascinating system, such as whether there has been co-evolution of the flies and their prey, or what exactly attracts certain fly species to frog species. (DC)
Atelopus laetissimus
Atelopus laetissimus by Luis Alberto Rueda-Solano
January 31, 2022: Most frogs and toads (anurans) synchronize the exact time they deposit their gametes through 'amplexus', where typically a male grasps the female tightly from behind until she deposits her eggs. In the Happy Toad or Santa Marta Harlequin Toad (Atelopus laetissimus) of Colombia, Rueda-Solano et al (2022) studied how the amplexus in this species has evolved to last for months! Males that amplex a female before other males have a high chance of breeding, so it is advantageous to be the first male in finding a female. Although she may not ready to reproduce, the male must wait until the female decides to do so. They reported the female toad will carry the smaller male around for up to four months. Males scramble for females where larger males have the advantage, and once in amplexus, the male holds on with a force 80 times his own weight, and those with larger forelimbs are harder to dislodge. While the male waits, he must defend his position on the female's back, other males will try to displace him. Their experiments showed the female helps defend her mate from interlopers. During amplexus, the male cannot feed and loses up to 30% of his initial weight, which he can gain back in just one week post-breeding. (Andrew Crawford and Luis Alberto Rueda-Solano)
Allobates femoralis
Allobates femoralis by Jean-Pierre Vacher
January 24, 2022: Picking the right spot to lay eggs or tadpoles is crucial to population persistence of aquatic breeding amphibians. Despite its relevance to population growth, relatively little is known about how frogs discover and select water bodies for egg or tadpole deposition. In a simple but clever field experiment, Serrano-Rojas and Pašukonis (2021) demonstrate that in the tadpole-transporting Brilliant-thighed Poison Frog (Allobates femoralis), frogs (primarily males) rely on volatile cues to find pools in the tropical rainforest. Frogs were more likely to lay tadpoles in pools surrounded by decomposing litter that had been soaked in stagnant water than in pools containing cues from conspecific tadpoles and pools with clean water. Thus, frogs rely on volatile cues from litter decomposing in water to discover suitable pools where to lay their tadpoles. (ACatenazzi)
Xenopus laevis
Xenopus laevis by William Leonard
January 17, 2022: Oxygen is necessary for life in most non-photosynthetic organisms and without it, irreversible brain damage and death may be the consequence. However, these effects can be mitigated with hyperbaric oxygen medical therapy. Özugur et al. (2021) explored another potential therapy using microalgae. In their experiments, transcardially injected green algae or cyanobacteria into Xenopus laevis tadpoles traveled to the brain where they produced oxygen when exposed to light. This production was sufficient enough that when the tadpoles were placed in hypoxic conditions, the microalgae produced enough oxygen to rescue brain activity. While these results have a long way to go before they can be used in human medical procedures, there are many applications they can now be used in to enhance studies, such as improving oxygen levels in cell or tissue cultures, increasing control in graded oxygen experiments, and experimentation with bilateral imbalances of oxygen on neural and motor function. (AChang)
Hyperolius cinnamomeoventris
Hyperolius cinnamomeoventris by Iris Starnberger
January 10, 2022: Wetlands provide fundamental ecosystem services and important habitat for many species, including amphibians. However, for much of the world, we lack basic information on how wetlands are being impacted by human activities, or on policy that protects them from degradation. Mind'je and colleagues (2021) assessed land use change from 2000 to 2018 in an urban wetland in Kigala, Rwanda, by surveying plant and frog diversity to understand the implications of land use change for biological communities, and by surveying local residents with a questionnaire. They found about two-thirds of wetlands that existed in 2000 had been lost by 2018 – urban development, which was just beginning to impinge on the wetland at the beginning of the study, rapidly expanded to cover three-quarters of the study area by the end. A quarter of local residents had moved there within the last 6 years and, beyond new settlements, this wetland is largely impacted by agriculture, irrigation, and waste dumping. Along the development of the wetland, the authors found that the wetland plant and frog communities were now dominated by disturbance-tolerant, generalist species (e.g., Phrynobatrachus natalensis, Kassina senegalensis, Ptychadena spp., Hyperolius kivuensis, H. viridiflavus). More sensitive or specialized amphibians (e.g., Hyperolius lateralis and H. cinnamomeoventris) were no longer present. The authors point to the urgent need for local conservation and restoration work. (ESteigerwald)
Bolitoglossa compacta
Bolitoglossa compacta by Wouter Beukema
January 3, 2022: Happy 2022! We bid farewell to the past year, which has been fraught with loss. In 2021, the world lost not one but two dedicated amphibian advocates and scientists– first, one of our strongest allies, Phil Bishop, who was the Chief Scientist at our conservation partners Amphibian Survival Alliance and Co-Chair of the IUCN SSC Amphibian Specialist Group, and then, most impactful for the AmphibiaWeb family, David Wake, our co-founder and director for the past 20 years. Dave was not only the inspiration for AmphibiaWeb, he was our personal advisor, mentor, and friend. In his memory, the AmphibiaWeb team is as committed as ever to the vision and mission that Dave inspired and that still informs our work. Despite the challenges of 2021, we added or updated 102 species accounts and over 150 range maps, added 150 new species to the database, and updated the family richness maps -- one of our most productive years. We also submitted for peer review the first State of the Amphibia report, a collaboration of the senior team at AmphibiaWeb and partners at AmphibiaWeb Ecuador and AmphibiaChina (Preprint available). Looking forward, we have a lot of new plans and activities already in motion for the new year. Please join and connect with AmphibiaWeb in 2022 to keep up with amphibian research and conservation!


back to News by Year
Agalychnis callidryas eggs eaten by Imantodes inornatus
Agalychnis callidryas eggs eaten by Imantodes inornatus by Karen Warkentin (courtesy Karen Lips)
December 27, 2021: Biodiversity is declining at unprecedented rates worldwide. Yet cascading effects of biodiversity loss on other taxa are largely unknown because baseline data are often unavailable. Zipkin et al. (2021) document the collapse of a Neotropical snake community after the invasive fungal pathogen Batrachochytrium dendrobatidis caused a chytridiomycosis epizootic leading to the catastrophic loss of amphibians, a food source for snakes. After mass mortality of amphibians, the snake community contained fewer species and was more homogeneous across the study site, with several species in poorer body condition, despite no other systematic changes in the environment. The demise of the snake community after amphibian loss demonstrates the repercussive and often unnoticed consequences of the biodiversity crisis and calls attention to the invisible declines of rare and data-deficient species. (Karen Lips)
Gastrotheca guentheri
Gastrotheca guentheri by Giovanni Onore (BIOWEB)
December 20, 2021: Dollo's law claims that once a complex phenotype, such as teeth, is lost, it will not evolve again in the same form. But there are exceptions. Gastrotheca guentheri, a possibly extinct species from Ecuador and Colombia, is the only frog out of more than 7000 species with teeth on the lower jaw (dentary). Salamanders and caecilians have dentary teeth, but these were lost in the ancestor of frogs more than 200 mya. Are these "re-evolved" teeth the real thing, and not pseudoteeth, bony pointed projections on the lower jaw? To answer this, Paluh et al. (2021) examined the fine-scale, development of Gastrotheca guentheri embryos using histology and computed tomography. They found that the dentary teeth are in fact, true teeth, with a typical root canal with nerves and blood vessels, dentine, and enamel. Although referred as "teeth re-evolving", the focus should be on expression of genes involved in mineral deposition. If loss of a complex structure results from a disabling mutation in developmental genes, then the function of those genes degrades over time, making a re-evolution of the tooth-producing pathway unlikely. In the case of Gastrotheca, it appears that the ancient developmental pathway for tooth development has been maintained, an unusual phenomenon deserving more attention. (DC)
Rhinella marina
Rhinella marina by Eric Vanderduys
December 13, 2021: Cane toads (Rhinella marina) were famously introduced to Australia as a potential biological control in 1935. Because Australia lacks bufonid frogs, these toxic toads have very few natural predators in Australia and have consequently rapidly expanded across the continent while achieving spectacularly high densities (more than 10 times greater than in their native range in South America). DeVore et al. (2021) show that this lack of predators in Australia has changed the selection regime for cane toads in a manner that has established an intraspecific co-evolutionary arms race. Cane toad tadpoles compete for food resources. In their natural South American range, tadpoles opportunistically consume smaller, more vulnerable early stage tadpoles. However, in Australia, this competitive interaction has been escalated dramatically – larger tadpoles are 2.5 times more likely to consume smaller tadpoles. Furthermore, Australian cane toad tadpoles have uniquely evolved an attraction to early-stage tadpoles mediated by the presence of maternally-invested toxins (e.g., bufadienolides) in the smaller tads. Indeed, in laboratory experiments, Australian cane toad tadpoles were 29.5 times more likely to enter traps baited with smaller cane toad tadpoles than were native South American tadpoles. The authors note that cannibalism is no longer an opportunistic behavior in Australia: Australian tadpoles shift to a targeted foraging strategy aimed at locating and consuming conspecifics as soon as they chemically detect the presence of smaller tadpoles. This strategy not only provides a rich nutritional resource, but does so while simultaneously removing future competitors. (JM)
Micrixalus fuscus
Micrixalus fuscus by Zeeshan Mirza
December 6, 2021: Foot-flagging or "dancing" in frogs is an elaborate courtship behavior, usually displayed by breeding males, in which the hind leg is raised above the head and rotated backwards. This behavior has been documented in eight separate frog genera, many of which are distantly related, and is believed to replace calls during sociosexual communication in species that live in noisy environments, such as waterfalls. These displays can be highly variable, with some species incorporating toe taps while others rotating both legs at the same time. Anderson et al. (2021) investigated the physiological mechanisms behind this behavior to better understand the convergent evolution of the trait. They found that androgen receptor messenger RNA (AR mRNA) was elevated in the thigh muscle of all foot-flagging species when compared to non-flagging species, but there was no statistical difference in AR mRNA in the central nervous system. These findings lend support to the hypothesis that selection in the endocrine system may be the mechanism of convergent changes in various suites of behavior. (AChang)
Andinobates cassidyhornae
Andinobates cassidyhornae by Luis A. Mazariegos
November 29, 2021: Research on the fascinating Neotropical poison frogs has focused mainly on two separate tracks, with limited integration: either on the evolution of toxicity, warning coloration (aposematism) and mimicry, or on reproductive strategies and parental care. Carvajal-Castro et al. (2021) attempt to unify these research areas in an updated phylogenetic framework. In reconstructing ancestral states, they found that male parental care is most likely to be the ancestral condition, and that aposematism likely evolved before the use of small leaf axil pools for breeding (phytotelmata). The authors found the complexity of parental care (i.e., intensive care of small numbers of offspring that are transported separately to phytotelmata) correlated with aposematism. The authors also asked whether tadpole deposition sites (phytotelmata versus non-phytotelmata) and components of aposematism (conspicuousness and toxicity) were evolutionarily correlated. They found that transitions from crypticity to conspicuousness, and from non-toxic to toxic, were significantly more common in phytotelm-breeding lineages with complex care. They hypothesize that aposematism may provide a kind of "umbrella trait" which allows the evolution of complex breeding behaviors, but also that these complex reproductive strategies may have favored the evolution of aposematism. Hence, these two suites of traits may have coevolved, each promoting the evolution of the other. They also found a negative correlation between aposematism and clutch size and the number of tadpoles transported at one time, which is consistent with changing life-history strategies associated with increased complexity and intensity of parental care. They argue increased aposematism and decreasing clutch-size may arise from the need to display warning coloration during long-range tadpole transport. (KSummers)
Rana draytonii
Rana draytonii by Bill Stagnaro
November 22, 2021: Drought, exacerbated by climate change, has been especially devastating to amphibians globally. Even so, Moss et al. (2021) found that amphibian communities can be resilient to drought and may even benefit native amphibians by reducing invasive species on the landscape. They analyzed a decade of amphibian breeding data in California’s San Francisco Bay Area from 233 ponds (a mix of temporary and typically permanent ponds) and seven species. This included federally endangered California Tiger Salamander (Ambystoma californiense) and federally threatened California Red-Legged Frog (Rana draytonii) in addition to globally invasive American Bullfrog (Rana catesbeiana). This ten-year study included a multi-year extreme drought, which reduced the occupancy of all amphibians across the landscape by drying out many ponds, including ponds that are typically permanent. Although all species had reduced occupancy during the drought, native amphibian species returned to pre-drought occupancy rapidly. In fact, the Red-Legged Frogs occupied more habitats at the end of the survey period than the beginning, despite the drought. Invasive Bullfrogs and fishes were extirpated by the drought and did not recover post-drought. Lastly, their study showed that developed land limited habitat colonization by three species, including the two federally protected species, whereas grassland and forest habitats increased colonization by Western Toads (Bufo boreas), Red-Legged Frogs, and two Taricha newt species. Management can promote resiliency of pond-breeding species by maintaining more ponds with diverse hydroperiods and by protecting natural upland habitats. (MLambert)
Buergeria japonica
Buergeria japonica by Timothy Johnson
November 15, 2021: Many species of frogs and toads call in large choruses. However, communication can be difficult when multiple individuals are calling at the same time, like humans trying to hold a conversation at a crowded party. When multiple male frogs are calling at the same time, female attraction to individual calls is often reduced. Despite this cost, males of some species deliberately overlap their mating calls, “synchronizing” their signals. Legett et al. (2021) examined the potential functions of synchronized mating calls in a Japanese treefrog, the Ryukyu Kajika Frog (Buergeria japonica). They found that call synchronization may benefit male Ryukyu Kajika frogs in two ways. One, synchronized calls are louder than non-synchronized calls, attracting females to the chorus from a greater distance. Two, synchronized calls reduce the attraction of predators and parasites, such as frog-biting mosquitoes. Interestingly, female Ryukyu Kajika frogs attraction to individual calls was not affected by synchronization, suggesting that relaxed sexual selection may be key to the evolution of synchronized signaling strategies. (Henry Legett)
Litoria phyllochroa
Litoria phyllochroa by Jodi Rowley
November 8, 2021: Over the Australian winter and into the spring 2021, frogs have been found sick and dying across Australia, particularly along the east coast. In the last several months, the Australian Museum's FrogID Project has received almost 1,500 reports of dead and dying frogs, spanning thousands of kilometers and over 30 species. Many reports are of dozens of dead frogs. The impact of this widespread mass mortality event on Australia's frogs is not yet known, but concerns are held, especially for already threatened species. An investigation is underway into the cause of this event and its impact on Australia's frogs. Early results reveal that the amphibian chytrid fungus is playing a part, but may not be the full story. It is an ongoing mystery and tragedy baffling experts (Guardian, 19 Sep 2021). (Jodi Rowley)
Batrachoseps attenuatus
Batrachoseps attenuatus by Heidi Rockney
November 1, 2021: Social behaviors typically evolve due to the benefits of associating with others, but they can also present risks such as disease transmission. Ritchie et al. (2021) examined the costs of sociality in the California Slender Salamander (Batrachoseps attenuatus), a terrestrial salamander, which gather in close social aggregations, by testing whether sociality increased transmission risk of Batrachochytrium dendrobatidis (Bd), a fungal pathogen that causes the disease chytridiomycosis. In captivity, B. attenuatus exhibited random mixing within social groups, resulting in high contact rates and high transmission, resulting in 50% mortality after one month. When social group size was manipulated, direct Bd transmission was magnified in larger social groups. The results show that the innate behavior of group formation represents a per-individual risk of socially acquired pathogens and highlights a cost of sociality in terrestrial salamanders, underscoring the general susceptibility of social animals to novel invasive pathogens. (VV)
Rana sylvatica
Rana sylvatica by Michael Graziano
October 25, 2021: Amphibian larval development is highly temperature sensitive; larvae develop faster at warmer temperatures and slower at cooler ones. Countergradient variation is a form of local adaptation where – for example, in the Wood frog (Rana sylvatica)- tadpoles living in colder ponds (due to more enclosed, shaded forest canopies) are adapted to develop at faster rates than tadpoles from populations living in warmer ponds (with more open, sunnier forest canopies). This allows tadpoles in cold ponds to developmentally catch up to tadpoles in warmer habitats. The original study (Skelly 2004) found that this countergradient variation occurs at very small 'microgeographic' spatial scales, i.e., Wood frog populations are adapting to local environmental conditions well within the distance that the frogs can disperse and interbreed within a metapopulation. Arietta and Skelly (2021) performed the identical experiment with the same Wood frog populations 17 years later (~ 6-9 frog generations) and found persistent microgeographic countergradient evolution as before with overall Wood frog embryonic developmental rates accelerated by 14-19%. During this period, the forest canopy over these ponds generally became more shaded, but pond temperatures still increased across the metapopulation. With warmer ponds, it would be expected that the Wood frog populations would evolve slower tadpole development rates, not faster. Critically, ponds experiencing more change (i.e., canopy cover and temperature change) also had declining populations and several disappeared altogether. Overall, their experiment illustrates how amphibians might be able to adapt to environmental change relatively quickly and at relatively small spatial scales, but, even so, there are limits on rescuing populations from rapid environmental change through evolutionary adaptation. (MLambert)
Rhinella icterica
Rhinella icterica by Mario Sacramento
October 18, 2021: Amphibians are known for their very permeable skin that functions in gas and water exchange. Frogs, in particular, have colonized very dry habitats worldwide that would create seemingly conflict between the need for oxygen uptake (required for metabolism) and water loss (potential desiccation). To better understand how frogs, and especially their skin, cope with dry habitats, Mailho-Fontana et al. (2021) compared the skin, physiology, and behavior of two closely related toad species, the Yellow Cururu Toad and Cope's Toad (Rhinella icterica and R. jimi, which is now known as R. diptycha, respectively) that experience different climates. The authors found that the Cope's Toad from drier climate regions had thicker and more glandular skin, showed lower rates of water loss and displayed stereotyped behaviors to increase water uptake when dehydrated. These findings link differences in form, function, and behavior to illuminate strategies for desiccation resistance in frogs. (MWomack)
Plethodontohyla notosticta
Plethodontohyla notosticta by Rob Schell
October 11, 2021: Although the higher taxonomy of amphibians has been controversial, in the last decade the phylogenetic analyses of major lineages have largely converged. The analysis by Hime et al. (2021) substantially increases the number of molecular characters available based on the anchored hybrid enrichment method. Their salamander and caecilian trees are almost identical to previous studies. The phylogeny of higher frog taxa is largely the same as those of Zhang et al. (2013) and Feng et al. (2017) with some minor differences among a few families in the Ranoidea and Hyloidea. Notably, Himes et al. examined incongruence among individual genes, from which they concluded that phylogenetic signal deep in amphibian phylogeny varies across genes in a manner consistent with incomplete lineage sorting in the ancestral lineage. This accounts for some of the disagreement among different phylogenies. (DCC)
Engystomops pustulosus
Engystomops pustulosus by Tobias Eisenberg
October 4, 2021: Amphibians serve as the inspiration to several biomedical research studies, including tissue regeneration (Mexican Axolotl, Ambystoma mexicanum), suture substances (Chinese Giant Salamander, Andrias davidianus), and cryogenics (Wood Frog, Rana sylvatica). The latest inspiration comes from the foam nests that some frogs create during reproduction, which protects eggs and larvae from predators, parasites, desiccation, and aides in gas exchange, and temperature regulation. Brozio and colleagues (2021) demonstrated that the foam, created by aerating reproductive secretions, of Túngara Frog (Engystomops pustulosus) has potential as a topical pharmaceutical foam for drug delivery as it is stable for up to 10 days, is biocompatible, and is capable of carrying a variety of compounds, including antibiotics. These exciting results require more testing, both in Túngara Frog as well as other foam nest building frog species, and may have broad uses in medicine. (AChang)
Phyllobates terribilis
Phyllobates terribilis by Victor Fabio Luna-Mora
September 27, 2021: What do Pitohui birds and Phyllobates poison frogs have in common? They both sequester the potent neurotoxin called batrachotoxin – and presumably resist its lethal effects. Batrachotoxin binds to voltage-gated sodium channels, a group of proteins that are partly responsible for action potentials, and thus interrupt the nervous system functions. Previous studies have predicted that the voltage-gated sodium channels from Phyllobates poison frogs possess changes in the amino acid sequence that prevent batrachotoxin from binding– yet Abderemane-Ali et al. (2021) find that batrachotoxin readily binds to poison frog and pitohui sodium channels, suggesting that these animals have a different mechanism of toxin resistance. They propose that circulating "toxin sponges" could bind to batrachotoxin, preventing it from binding to the voltage-gated sodium channels. Although a batrachotoxin-binding protein remains elusive, a unique toxin-binding protein called saxiphilin (which binds saxitoxin, the toxin underlying red tides) was discovered in bullfrogs (Rana catesbeiana) in the 1990s, suggesting that toxin sponges may be a common way for frogs to counter the potential lethal effects of toxin accumulation. Perhaps even more intriguing is the potential for "toxin sponges" to allow toxin sequestration and resistance to evolve in parallel (Marquez 2021, Abderemane-Ali et al 2021). (RT)
Rana sierrae
Rana sierrae by Sean Barry
September 20, 2021: The pathogenic fungus Batrachochytrium dendrobatidis (Bd) has caused a global panzootic among amphibians, but some skin microbes can provide protective effects against Bd. Ellison, Knapp and Vredenburg (2021) report on their study of longitudinal patterns in the skin microbiome of the endangered Sierra Nevada Yellow-legged frog (Rana sierrae) in two wild populations. Lower skin bacterial diversity was significantly correlated with greater microbiome stability over time. Amplicon sequence variants (ASV) with intermediate relative abundance were the most volatile over time, and ASVs with high relative abundance were the most transient. Their investigation suggests that efforts to develop probiotic treatments to combat Bd should focus on bacteria that are found at high relative abundances in some members of a population, as these strains are more likely to persist and remain stable in the long term. (VV)
Dendrobates auratus
Dendrobates auratus by Frank Steinmann
September 13, 2021: Can poison frogs count? Khatiwada and Burmeister (2021) address this question in the Green and Black poison frog (Dendrobates auratus). The study of counting in non-human animals has a long history, mainly focused on birds and mammals with research on amphibians being relatively rare. In this study, they used a foraging task (hunting flies) to see if the poison frog could distinguish between different numbers of flies. The frogs did well comparing small quantities (1 to 2 or 1 to 3), but beyond that did not show significant discrimination abilities. The frogs did not show any ability (or motivation) to discriminate large quantities, even with highly skewed ratios, showing they did not follow an approximate number system mediated by Weber’s law. Surprisingly, their numeracy with respect to large numbers was inferior to those of plethodontid salamanders and tree frogs from previous studies. The authors suggest that the context might affect motivation, and that these frogs might show more advanced capabilities in the context of parental care (transporting and depositing tadpoles) as opposed to foraging. Hence, further research is warranted. (KSummer)
Salamandra salamandra bernardezi
Salamandra salamandra bernardezi by Frank Pasmans
September 6, 2021: The chytrid fungus Batrachochytrium salamandrivorans (Bsal) has recently emerged in Europe, where it is devastating salamander and newt populations. While the disease mainly affected northwestern Europe, it recently caused mass mortality in northern Spain. The Iberian peninsula is a hotspot of salamanders and newts, and in a joint effort between Spanish, Belgian and Australian scientists, Bosch et al. (2021) assessed the risk of Bsal for this salamander-rich region. Fortunately, Bsal appears to be limited to a single outbreak site at present. However, we identified six conservation units at high risk and priority areas as targets for the most urgent disease surveillance and biosecurity measures. The study stresses the importance of region specific conservation strategies, coupling efficient wildlife disease surveillance to the ability to rapidly and drastically respond, but equally points to the importance of "clean trade" (absence of pathogens from the amphibian trade), amphibian population monitoring and closing gaps of knowledge regarding salamander diversity. (Frank Pasmans)
Desmognathus ocoee
Desmognathus ocoee by Grant Connette
August 30, 2021: Despite lacking specialized climbing structures, a wide range of salamanders are known to climb vegetation, trees, or rocks. Their ability to cling and climb allows these salamanders access to more food resources, to more suitable microclimates, and to escape predators. O'Donnell and Deban (2021) explored what factors contribute to this ability across a wide range of size, morphology, and ecological niches in salamanders. They found that the adhesive nature of their mucus coating was a major factor, but that cling ability also was associated with body mass and the amount of body contact area utilized, which include feet, tail, belly, and ventral surface of their head, to increase cling. The best clingers in their experiments were the small plethodontid salamanders, such as Batrachoseps attenuatus, Desmognathus aeneus, D. ocoee, Eurycea guttolineata, and E. wilderae. However, plethodontid salamanders in general, like large salamander Desmognathus quadramaculatus, were comparable or exceed the cling ability of arboreal and scansorial frogs. (AChang)
Hyperolius concolor
Hyperolius concolor by Daniel Portik
August 23, 2021: A new study by Kpan et al (2021) assessed the resilience (the ability of species assemblages to return to a previous state following disturbance) of amphibian assemblages to selective logging in one of the last primary rainforests in Ivory Coast, the Taï National Park. They revisited identical sites and used identical, standardized methodology spanning a time period of 30 years and 45 years after initial disturbance. They found that forest structure slowly recovered towards old growth forest structure over the course of 45 years, with most visible changes occurring in the last 15 years. The frog assemblage composition in formerly disturbed sites followed the slow forest recovery process; yet, the frog species composition was still distinctly different from old growth forest assemblages by the end of the study. Thus, if the goal is to conserve and restore original forest diversity in logged forest ecosystems, significantly longer felling cycles are needed. (VV)
Pristimantis bogotensis
Pristimantis bogotensis by Giovanni Alberto Chaves Portilla
August 16, 2021: When considering animals living in regions that regularly freeze, endothermic birds and mammals with their thick layers of fat and insulating coats of fur or feathers may come to mind. Ectothermic species, such as amphibians, also occur in such environments; among the best studied are the North American wood frogs, Rana sylvatica, which occur at high latitudes where freezing temperatures are frequent in winter. Wood frogs use cryoprotectants including elevated blood glucose to prevent their tissues from freezing when temperatures drop below 0° C. Tropical amphibians occurring at high elevations may also experience freezing temperatures, but rather than seasonally cold weather, these tropical taxa can experience cold snaps at any time of year ranging from a few minutes to several hours in duration. Carvajalino-Fernández et al. (2021) has provided the first investigation of freeze tolerance in tropical amphibians with their study of six species of Colombian Pristimantis frogs, three of which occur in tropical montane cloud forest habitat that never freezes (1560 m elevation), and three of which are found in the higher elevation Andean páramo (at 3400-3700 m). They show that two of the three species of páramo Pristimantis elevate their blood glucose levels substantially while also experiencing extracellular freezing, thus confirming that freeze tolerance has evolved in this group. Given that a diverse array of 40 or more amphibian species occupy páramo habitats, the authors speculate that freeze tolerance has likely evolved many times in this diverse amphibian community. (JM)
Eleutherodactylus gundlachi
Eleutherodactylus gundlachi by Ariel Rodriguez
August 9, 2021: Amphibians are good study subjects to test whether differences in reproductive phenology may separate niche space and thus allow for increased numbers of co-occurring species given limited resources. Bignotte-Giró et al. (2021) studied five endemic Eleutherodactylus species* that coexist in a mountain rainforest in Cuba to test the hypothesis that in Neotropical humid sites, reproductive activity in sympatric species will vary in the time of occurrence in order to minimize complete temporal overlap. Reproductive phenology was inferred from seasonal variation in the number of sexually active individuals, their gonad developmental stage, and male vocal activity from January 2003 to March 2004. The study found no support for the hypothesis of temporal segregation in reproduction and instead found a prolonged reproductive pattern in all five species, with decreased breeding intensity in the cooler months (November–February). Thus, if niche diversification is occurring, it must be explained along different ecological parameters than reproductive phenology. (*E. auriculatus and E. dimidiatus are widely distributed across the island, whereas E. cuneatus, E. gundlachi, and E. intermedius are known only from the eastern ranges of Cuba.) (VV)
Leptodactylus pentadactylus
Leptodactylus pentadactylus by Andreas Nöllert
August 2, 2021: Most amphibians secrete distasteful or toxic substances from their skin. Several groups wield toxins that can be lethal to other animals, or even to themselves. Animals can evolve resistance to toxins through mutations in proteins that prevent toxins from binding. Although these mutations can provide resistance, they often occur in important regions of a protein, such as those critical to nervous system functions. Thus, a problem arises: how can animals avoid the negative effects of mutations that also provide resistance? A pair of recent studies, one on the toxic salamanders Taricha (Gendreau et al. 2021) and another on frogs of the genus Leptodactylus (Mohammadi et al. 2021), which consume toxic toads, suggest that gene duplication is the key; one gene copy can help animals develop toxin resistance while the other copy maintains a functional nervous system. Both studies also show evidence for a fascinating molecular process known as gene conversion, wherein duplicate copies of one gene retain more similar-than-expected DNA sequences. During homologous recombination, two copies of a genome line up and exchange pieces of DNA; however, when two copies of a gene are near each other in the genome, the wrong genes can line up and exchange genetic material, maintaining genetic similarity between duplicate copies of a gene. In newts, gene conversion appears to have copied resistance-conferring mutations from one gene domain to another. In Leptodactylus frogs, strong natural selection countered the force of gene conversion, resulting in one toxin-resistant gene and one toxin-sensitive gene. How newts and frogs regulate the use of these different gene copies remains unknown and will be an exciting future research topic. (RT)
Mantella aurantiaca
Mantella aurantiaca by Gonçalo M. Rosa
July 26, 2021: Zoos can be important animal conservation partners because they can educate the public and often run species-specific conservation and husbandry programs. However, historically, management studies in zoos have mainly focused on mammals. The COVID-19 pandemic provided zoos with a unique opportunity to observe changes in animals' behavior in the absence of visitors and to identify ways to improve animal welfare conditions. Staff at the Wildfowl and Wetland Trust (Boultwood et al. 2021) in the United Kingdom took advantage of this situation by recording how amphibians used their habitats when only essential workers were allowed in, when support staff were allowed, and then when visitors were slowly allowed back. They also took into account various life history traits and differences in habitat. They found that while species with aposematic traits appeared to cope better, all species had an initial "visitor effect" during which they hid more, followed by varying periods of habituation. Their findings emphasize the need to create enclosures based on ecological evidence so that the public can continue to learn from amphibians at zoos with minimal stress to the animals. (AChang)
Salamandra salamandra
Salamandra salamandra by Joachim Nerz
July 19, 2021: The loss of amphibians is predicted to have cascading ecological effects. Laking and colleagues (2021) examined the impact of disease-driven loss of salamanders on the forest leaf litter decomposition through trophic cascades. Using paired mesocosms within a Belgian forest, researchers tested the effect of Fire salamander (Salamandra salamandra) presence on the trophic cascade that results in the decomposition rate of both good quality, or faster decomposing maple (Acer pseudoplatanus), and poorer quality, or slower decomposing oak (Quercus robur), leaf litter, over an 18 month period. The presence of salamanders reduced decomposition rate of Quercus litter up to 20%, likely through higher predation pressure on detritivores. In addition, the litter microbiome showed less bacteria associated with leaf litter degradation in the presence of salamanders. Thus, salamanders influence ecosystem dynamics and their presence helps retain leaf litter, which in turn may decrease carbon dioxide release, a factor in climate change. (VV)
Pseudophryne guentheri
Pseudophryne guentheri by Ryan J. Ellis
July 12, 2021: Human-driven habitat loss and modification is one of the greatest threats to biodiversity and is occurring faster now than ever before. As humans continue to modify the landscape, halting species declines and making informed conservation decisions will require an understanding of how species respond to habitat modification. Unfortunately, this information is lacking for many amphibian species. Integrating over 126,000 citizen science observations with a global measure of human habitat modification, Liu et al. (2021) quantified the effects of habitat modification for 87 frog species (36 percent of Australia’s frog species) and ranked them based on their tolerance to human-modified environments. Alarmingly, 70 percent of the species examined were negatively affected by habitat modification. Assessing the species’ traits, they found that generalists coped best in human environments. The authors call for greater consideration of frogs in urban planning decisions and stronger conservation measures to ensure the long-term persistence of frog populations, especially those species less tolerant of human impacted landscapes. (Gracie Liu)
Boana punctata
Boana punctata by Mauro Teixeira Junior
July 5, 2021: It has long been hypothesized that large rivers such as the Amazon may prevent dispersal of terrestrial organisms and contribute to speciation. Alfred Russell Wallace famously proposed the riverine barrier hypothesis in reference to the diversity and distribution of Amazonian primates. However, these ideas attempted to explain differences in terra firme communities on both sides of large rivers. What about organisms living on the river itself? Marin da Fonte et al (2021) explored amphibian communities living on Amazonian floating meadows, finding 49 frog and one caecilian species across 57 sites. One of the most frequent species was Boana punctata shown above. Floating meadows may be important means of dispersal along rivers, and the associated frog fauna provides opportunities to test hypotheses concerning ecological processes governing these communities. Testing one such hypotheses, the Hanski core-satellite model, the authors found that the floating meadows supported a group of core species closely associated with this habitat, and for which river distance did not greatly influence species composition, and a group of satellite species composed of accidental rafters from várzeas and terra firme forests. Thus, for core species the floating meadows may promote long-distance riverine dispersal, a finding that goes against the flow of classic depictions of large rivers as barriers. (ACatenazzi)
Elachistocleis bicolor
Elachistocleis bicolor by Mario Sacramento
June 28, 2021: Most vertebrates have teeth, but a number of lineages have completely lost teeth including familiar groups like seahorses, turtles, birds, anteaters, baleen whales. Several groups of frogs are well known to lack teeth, such as true toads in the family Bufonidae and the dart frogs in the Dendrobatidae family. But the extent of tooth loss across living amphibians has not been well documented. Based on a large-scale survey of teeth across more than 500 genera of amphibians using CT-scans from the oVert project, Paluh et al. (2021) estimate that frogs have completely lost teeth more than 20 times, largely related to eating small prey such as ants and termites. This new framework leads to frogs being an unparalleled system to investigate what happens to the genetics and developmental processes related to making teeth in lineages that lose them. (DBlackburn)
Oophaga sylvatica
Oophaga sylvatica by Brad Wilson
June 21, 2021: The world's tropical rainforests hold the highest amphibian biodiversity, and increasing habitat modification and fragmentation in these ecosystems have untold cascading impacts on local food webs. Moskowitz et al. (2020) sheds light on how the replacement of tropical rainforests with pasture lands affects chemical defenses in Oophaga sylvatica through changes in prey item composition. The study, which was conducted with two U.S. high school science classes, examined how leaf litter, leaf litter invertebrate communities, and alkaloids in O. sylvatica related to each other in the two environments. Their results showed significant differences in diet and alkaloid profiles in frogs based on land changes. Furthermore, their findings indicate that O. sylvatica have a dietary preference for specific ant species that are not as common in pasture lands as in forests. These findings have real-world implications for the management of this Near Threatened species as their aposematic coloration may be uncoupled from their chemical defense. (AChang)
Ranitomeya ventrimaculata
Ranitomeya ventrimaculata by Alberto Sanchez-Vialas
June 14, 2021: Microbiome-pathogen interactions are increasingly recognized as an important element of host immunity. Jervis et al 2021 describes landscape-scale pathogen-microbiome associations across altitudinal gradients in Ecuador about 30 years following amphibian declines (presumably caused by chytridiomycosis epizootics) and collected skin swab-samples which were metabarcoded using both fungal (ITS-2) and bacterial (r16S) amplicons. Stream breeding amphibians were most likely to be infected with Batrachochytrium dendrobatidis and were associated with increased abundance and diversity of non-Batrachochytrium chytrid fungi in the skin and environmental microbiome. The study also found that increased alpha diversity and the relative abundance of fungi are lower in the skin microbiome of adult stream amphibians compared to adult pond-breeding amphibians; and, stream tadpoles exhibited lower proportions of predicted protective microbial taxa than pond tadpoles, suggesting reduced biotic resistance. Thus, host breeding ecology may shape pathogen-microbiome associations at a landscape scale and may influence resilience in the face of emerging infectious diseases. (VV)
Schistometopum ephele
Schistometopum ephele by Andrew Stanbridge
June 7, 2021: O'Connell et al. (2021) investigated speciation in caecilians from the small oceanic island of São Tomé off the west coast of Central Africa in the Gulf of Guinea. Although small, the island of São Tomé exhibits dramatic variation in habitat type, with dry habitats in the north and rainforest in the south. They found two genetically distinct lineages of caecilians corresponding to yellow populations in the north (Schistometopum thomense) and brown spotted populations in the south (Schistometopum ephele). Further, they found evidence of hybridization at the transition of the two habitat types. The authors proposed that late Pleistocene volcanic activity separated caecilians on the island and favored local adaptation to wet and dry climates, leading to speciation and the maintenance of a hybrid zone. This study is one of the first to document speciation histories in caecilians and lays the groundwork for future studies of reproductive isolation in this group. (RBell)
Ambystoma tigrinum
Ambystoma tigrinum by Twan Leenders
May 31, 2021: The Mexican axolotl (Ambystoma mexicanum) is a famous example of a paedomorphic salamander – one that retains an aquatic, larval phenotype into adulthood. But the axolotl isn’t the only salamander with a strange life history! Across the tiger salamander species complex, life history is highly variable, including several species that are always paedomorphic, some that are always metamorphic, and many others that can exhibit either state depending on the population. In a study published in PNAS, Everson et al. (2021) examine the extent to which this variation in life history has influenced speciation in tiger salamanders. By analyzing a large genetic dataset from 19 Ambystoma species, they shed new light on species limits and gene flow across the complex. A major finding is that gene flow is common among species with different life history traits, and geography seems to be the best predictor of species limits. Apparently obligate paedomorphosis is not the species delimiter that one might assume. These new insights into the evolution of tiger salamanders chart a course for more informed use of these species in experimental, ecological, and conservation research. (Katie Everson)
Leptobrachella laui
Leptobrachella laui by Yik-Hei Sung
May 24, 2021: Amplexus, or the grasping of an individual frog during mating, is an important component in anuran reproductive behavior. There are nine described positions in which males grasp and are carried by females or are horizontally in-line with females. Sung et al. (2021) recently described a new amplexus position where female Leptobrachella laui grasps males around the waist (inguinal amplexus) and is carried by the male to an oviposition site in rock crevices. While it is unclear if this position is retained during ovipositioning, it is a consistent aspect of courtship behavior in the species. Sung and colleagues hypothesize that limited oviposition sites may drive this behavior, but they do not rule out the possibility of limited male numbers being a factor. Further studies into the reproductive behavior of L. laui and their close relatives is needed to better understand this novel reproductive behavior. (AChang)
Ambystoma maculatum
Ambystoma maculatum by Brad Moon
May 17, 2021: Understanding how genetic variation is maintained in a metapopulation is a longstanding focus in evolutionary biology. Historic resurveys of polymorphisms have offered efficient insights about evolutionary mechanisms, but so often are conducted on single, large populations, neglecting a more comprehensive view afforded by considering several populations in a single species or metapopulations. Giery et al (2021) resurveyed a metapopulation of Spotted Salamanders (Ambystoma maculatum) to understand the evolutionary drivers of frequency variation in an egg mass color polymorphism (clear and white egg masses) and found that there was demographic, phenotypic and environmental stability over the last three decades. They found evidence for two modes of evolution— genetic drift and balancing selection. Although their work did not identify the balancing mechanism from these data, they present a clear view of contemporary evolution in color morph frequency and demonstrate the importance of metapopulation-scale studies for capturing a broad range of evolutionary dynamics. (VV)
Laotriton laoensis
Laotriton laoensis by Henk Wallays
May 10, 2021: The COVID-19 pandemic has caused many nations to rethink their food and trade relationship with wild animals. Borzée et al. (2021) took this global crisis as an opportunity to review the current conservation issues associated with wild amphibian trade and reflect on new wildlife bans in China and Vietnam. The authors call for shifts in amphibian farming, such as phasing out farming of threatened local species to prevent loss of genetic diversity and disease risk to native populations and the abandonment of farming non-native species, which can lead to ecological damage through disease, predation of, and competition with native species. They suggest an evaluation of farming practices to improve the sustainability of farming abundant, local amphibians for consumption and trade. The authors acknowledge the need for more regulation in the amphibian pet trade to prevent the spread of disease and curb illegal collection of wild species, especially threatened ones. Lastly, they recommend expanding new wildlife bans to include more amphibian species, such as data deficient species or those suspected to be part of species complexes. (AChang)
David Wake
In Memoriam - David Wake
April 29, 2021: It is with profound sadness that we announce the passing of David Wake, professor emeritus University of California Berkeley, Museum of Vertebrate Zoology, on April 29, 2021. David Wake was co-founder and director of AmphibiaWeb. He spent his life studying the biology of amphibians, particularly salamanders, and he inspired countless undergraduates, graduate students, postdocs and colleagues. He was one of the first scientists to understand that declining and disappearing amphibians appeared to be a global phenomenon, which he began expressing at the first World Congress of Herpetology in 1989. In 1990, he co-sponsored (with Harold Morowitz) the first international meeting to discuss the decline of amphibians across the world (National Academy of Sciences, Irvine, California, 1990), and became the first chairman of the Task Force on Declining Amphibian Populations. With the launch of AmphibiaWeb in 2000, David sought to bring the conservation science and basic fact-based biology of all amphibians to a single place where everyone could access the information freely. Until his last day, David remained a tirelessly dedicated scientist and ally of the amphibians of the world. We will honor his legacy and vision by continuing to make AmphibiaWeb a valuable resource.
Ambystoma rivulare
Ambystoma rivulare by Henk Wallays
April 26, 2021: In amphibians, skin-associated bacteria inhibit infection by the fungal pathogen Batrachochytrium dendrobatidis (Bd), which causes chytridiomycosis and death in hundreds of amphibian species. A study by Nava-González et al (2021) analyzed Bd infection and skin-associated bacteria from two amphibian species, the salamander Ambystoma rivulare and the frog Rana (Lithobates) spectabilis that co-occur in tropical high-altitude sites in central Mexico. The study reports, 63% and 80% of sampled salamanders and frogs, respectively, testing positive for Bd, yet found not sick or dying animals, and identified numerous skin-associated bacterial genera with known Bd inhibitory effects. They also found that bacterial richness and relative abundance of inhibitory Bd bacteria were negatively related to intensity of Bd infection independent of species and seasons, providing further evidence that the skin microbiome of amphibians may play an important role in health and disease. (VV)
Xenopus laevis
Xenopus laevis by Ronn Altig
April 19, 2021: What do you get if you separate a developing frog embryo in two? Xenobots! A creative study by Blackiston et al. 2021 recently showed that, when extracted, the animal pole of a Xenopus embryo develops into a ball of skin cells that can move around, heal itself, display collective behavior, and survive for months if given nutrients. The effort represents a unique approach to generating biological robots (hence, "xenobots") that takes advantage of self-assembly in developing tissue as well as sensory systems already present in natural cell lines, rather than existing top-down approaches like printing or scaffolding cells together. Authors speculate that xenobots could be useful in biomedicine, exploration, and environmental rehabilitation. (RDT)
Rhinella marina
Rhinella marina by Bert Willaert
April 12, 2021: Does the global trade in pets such as amphibians, reptiles, birds, mammals, and fish favor species that make good invasive species, or do they become invasive because they are in the global pet trade? International trade in species have been increasing in recent years. Invasive species from the global trade have wide ranging harmful impacts on native flora and fauna, including on human health and economies. Despite the implications, addressing the question has not been easily done with a lack of data until an extensive meta-analysis by Gippet and Bertelsmeier (2021). Using an emergent global trade in ants as pets, they showed that there is an overrepresentation of species in the pet trade with the ecological traits linked to invasiveness; thus, global trade not only facilitates invasions, but that the pet trade favors specifically species inclined to be invasive. The authors advocate for banning, or minimally, acknowledgement of the risk with the international trade of wildlife species for pet or other purposes. (MK)
Hyla cinerea
Hyla cinerea by John P. Clare
April 5, 2021: Amphibians are freshwater animals, and most species cannot survive in saltwater. However, there are populations of a North American treefrog (Hyla (Dryophytes) cinerea) that have adapted to tolerate moderate levels of saltwater and inhabit coastal, saltmarsh ecosystems. The question is, how? Albecker et al. (2021) used gene expression to identify physiological mechanisms that underlie saltwater tolerance in coastal Green Treefrogs. They report that coastal frog populations differentially expressed several osmoregulatory genes that encode ion transporters, cellular adhesion components, and cytoskeletal components. Interestingly, they found coastal frogs expressed the gene that encodes glycerol, which is a compatible osmolyte that may help reduce water loss in hyperosmotic environments, which is a potentially novel mechanism of saltwater tolerance in frogs. Collectively, these findings highlight novel pathways, which in coastal Hyla cinerea improve control over cellular water balance and cell volume and may lead to salt tolerance in freshwater organisms facing habitat salinization. (Molly Albecker)
Platyplectrum ornatum
Platyplectrum ornatum by Eric Vanderduys
March 29, 2021: Amphibians stand apart from all other vertebrates in their great range of genome sizes. They are largest in the salamanders, where genomes are huge (over 100 gigabases), but genomes of some frogs enter the salamander range and can be quite large (the largest reported is for the myobatrachid Arenophryne rotunda). Caecilians are somewhat intermediate. The smallest amphibian genomes are also found in myobatrachid frogs. Lamichhaney et al. (2021) reports on the genome of Platyplectrum ornatum, a small burrowing frog from Australia with a very small genome -- 1.05 Gb, like that of birds. Transposable elements (TE) account for much of the extreme growth of amphibian genomes, but here all major classes of TE are reduced. Keeping TE's in check appears to be a key to genome miniaturization, and it may be driven by convergence in life history in small genomed species, in particular rapid and flexible tadpole developmental time and carnivorous tadpoles. Phylogenetic analysis shows that the genome is evolutionarily reduced rather than being a primary feature of this taxon. (DW)
Eurycea lucifuga
Eurycea lucifuga by Alexander Murray
March 22, 2021: Most terrestrial vertebrates detect sound using tympanic middle ears, which act as impedance- matching devices to convert airborne sound waves into fluid movement within the inner ear. Salamanders lack several key components of the tympanic middle ear, including the tympanic membrane (eardrum) and the air-filled middle ear cavity, and historically have been considered functionally deaf on land. In a recent study, Capshaw et al. (2020) demonstrated that the atympanic salamander ear is able to detect both airborne sound pressure and ground-borne vibrations. Their keen sensitivity to vibration appears to be what enables hearing in the absence of a tympanic middle ear: a sound pressure wave traveling in the air generates vibrations in the salamander’s skull and these vibrations are detected by the auditory organs of the inner ear. The detection of sound-induced head vibrations represents a very simple form of bone conduction that also has been shown to mediate aerial hearing in similarly atympanate snakes (Christensen et al. 2012). This bone conduction pathway may therefore represent a general mechanism that permits sound detection in animals, which lack specializations for hearing on land. Further comparative study of hearing mechanisms in "earless" vertebrates will shed light on how sound detection may have functioned in early vertebrates as they navigated the water-to-land transition 365 million years ago. (Grace Capshaw)
Desmognathus wrighti
Desmognathus wrighti by Ben Thesing
March 15, 2021: During this period of climate change, monitoring patterns of animal abundance is an important activity. Plethodontid salamanders show patterns of increasing abundance along montane transects in both temperate and tropical environments. A study by Hocking et al. (2020) documents patterns of abundance in the Great Smoky Mountains of southeastern USA along a transect extending up to 2,025 m elevation. Over 9,500 individual salamanders belonging to 14 species were studied. Many had elevational ranges exceeding 1000 m. The most widely distributed was Eurycea wilderae, which ranged from the lowest station (447 m) to the top. Three species occurred near or at the top, including the three most abundant (E. wilderae, Desmognathus wrighti, Plethodon jordani). These three were subjected to population abundance modeling. A mid-elevational peak of abundance at 1500 m was found for P. jordani, whereas D. wrighti, the smallest species, steadily increased in abundance to the highest point. Abundance of E. wilderae plateaued at about 1,600 m. The authors also determined the most important habitat factors for abundance and detectability for each species. This study provides important baseline data for salamanders of the southern Appalachians. (DW)
Triturus cristatus
Triturus cristatus by Joachim Nerz
March 8, 2021: Habitat creation is a common conservation tool for combatting the greatest threat to amphibians: habitat loss. However, data from local habitat use is rarely used in planning despite the recognition that habitats can vary across small spatial scales and between the cores and peripheries of species ranges, meaning that habitat correlates from one location may not predict habitat creation success elsewhere. In the Scottish Highlands, O'Brien et al. (2021) demonstrated a "co-development" model to habitat creation with a diversity of local stakeholders including farmers, golf course owners and employees. While there were tensions over conserving amphibians in places where people live and work, they show how conservation biologists can work closely with local landowners to benefit amphibians and people. They used rich local data collected on breeding for several species including common amphibians like the European Common Frog (Rana temporaria) and listed species like the Great Crested Newt (Triturus cristatus). They also collected dozens of ecological variables from over 80 local amphibian breeding ponds to identify which characteristics were best associated with the presence, abundance, and diversity of amphibians locally. The authors used these data to inform the construction and restoration of 25 ponds and monitored for four years after construction. They recorded a total of 51 colonization events resulting in amphibian communities matching those in nearby areas. They also documented a failure at one pond where miscommunication between the researchers and pond excavators led to a pond that will be perpetually inhospitable for amphibians. Even so, this new habitat benefitted a diversity of acid-loving plants and invertebrates, including an endangered dragonfly. (MLambert)
Centrolene ballux
Centrolene ballux by Laura Bravo Valencia
March 1, 2021: A new study (Velasco et al. 2021) predicts truly dire consequences from the synergistic interactions of global climate change and thermohaline circulation collapse on amphibians. Under a high carbon emissions scenario, temperate zone amphibians are predicted to show the lowest proportion of range loss. In contrast, Indomalayan, Afrotropical and Neotropical amphibians are highly vulnerable to even small levels of warming and they reach median range losses larger than 50% as early as the 2030s and more than 75% by the end of the century. If one adds in the impact of the Atlantic meridional overturning circulation (AMOC), the effect is magnified. Very large range attractions occur soon after additional freshwater is added and suitable areas for amphibians shrink throughout the century. Even if freshwater addition stops about midcentury, consequences of AMOC are persistent in simulations. Effects will be strongly nonlinear but decreased in richness could be as great as 70 - 80% over much of the earth, especially the Neotropics. The authors argue that the impact of a substantial weakening of AMOC might be extensive across many clades and biogeographical regions. (DW)
Buergeria robusta
Buergeria robusta by Pierre Fidenci
February 22, 2021: Frogs and toads are diverse in their habits, development, behavior and physiology, which allows a diversity of how these species interact with their landscapes and how landscape features, both natural, like mountains and streams, or anthropogenic ones, like roads or crops, impact gene flow and connectivity among populations. Covarrubias et al. (2020) recently reviewed 113 studies from the past 20 years conducted on 76 different frog species from temperate, subtropical, and tropical regions. Their review synthesized the impacts of various landscape features on gene flow and population genetic structure. They found urbanization and roads have some of the most pronounced negative impacts on gene flow, although many studies in all three ecoregions found no impacts by these landscape features. Natural features had mixed impacts, e.g., smaller streams tend to have positive impacts on gene flow whereas larger rivers often act as barriers. Importantly, many studies found no effect of most landscape features on gene flow and connectivity in frogs; one potential reason may be most studies to date have relied on classic molecular markers like microsatellites and mitochondrial DNA, which have less resolution to address landscape genetics questions. Modern data-rich genomic tools have seldom been used in frog landscape genetics studies, but expanding their use will greatly advance our understanding of how natural and anthropogenic features impact gene flow. Also important to address is the geographic bias revealed among other limitations in the reviewed studies, specifically a paucity of tropical and subtropical studies, which are particularly critical areas for conserving frog diversity. (MLambert)
Atelopus spumarius
Atelopus spumarius by James Patton
February 15, 2021: The mystery of anuran middle ear loss has new insights! Most frogs have a tympanic membrane and middle ear column (the columella) that help them hear airborne sound. Despite being well known for their calls, many frogs and toads are "earless", lacking the tympanic membrane and columella. The factors contributing to more than 38 evolutionary losses of the anuran ear remain unknown. Recently, Stynoski et al. 2020 raised and examined two earless toad species and two closely-related eared toad species. To their surprise, they found the middle ear column started to develop right on-time in both eared and earless species! However, in earless species, the middle ear column abruptly arrests development and remains either stagnant and very small or is completely resorbed. Thus, the genetic and developmental mechanisms which initiate middle ear differentiation are intact in earless species but perhaps changes in timing or expression of biochemical pathways that regulate the extension or differentiation of the columella after metamorphosis underlie convergent trait loss among toad lineages. Earless frogs are helping us understand the evolutionary and developmental mechanisms of trait loss; this discovery of developmental ear remnants further shows that lost traits are often not lost entirely. Their findings join many other studies that have found developmental remnants of lost traits, recently reviewed by Sadier et al. 2021. Studying development reveals key insights into evolutionary processes and this is certainly the case with earless frogs. (MWomack)
Ambystoma velasci
Ambystoma velasci by Joachim Nerz
February 8, 2021: Salamanders differ from all other vertebrates in their ability to regenerate lost parts and in their very large and highly variable genomes. Amazingly, salamanders not only can regenerate tails, digits and limbs but also virtually everything else, including much of the brain and the heart. Salamanders long have been known to have gigantic genomes, but what has been missed or ignored is the impact of genome size on the structure and function of genes. These phenomena are directly interrelated, and Sessions and Wake (2020) proposes dynamic interactions between growth and differentiation affecting morphogenetic processes, pattern formation and regeneration in unique ways. There probably is no specific genetic regulation of regeneration beyond processes normal for salamanders. Regeneration is an extension of their normal development. Salamanders are, in essence, much younger, especially at the cellular level, than implied by their chronological age; they are "forever young". (DW)
Anaxyrus punctatus
Anaxyrus punctatus by William Flaxington
February 1, 2021: Natural history museums are a critical resource and an invaluable tool for studying the historical dynamics of emerging wildlife diseases. In a recent study, Basanta et al. (2020) collected skin swabs from a complimentary set of amphibians that are museum-preserved and those encountered in the field to study the historical dynamics of the chytrid fungus (Batrachochytrium dendrobatidis, Bd) in Mexico. They found Bd-positive amphibians dating back to the late 1800's, predating known amphibian declines by almost a century. By sequencing Bd swab samples, they were able to conclude that two genetically-distinct lineages of the Global Panzootic Lineage (Bd-GPL) are present Mexico, and that there is little genetic structure within the contemporary Bd samples. These findings indicate that Bd has a long and complicated history in Mexico and call into question some earlier hypotheses that Bd was recently introduced and spread like a wave through the country. (AByrne)
Phil Bishop
In Memoriam - Phil Bishop
January 25, 2021: We are sad to share the news that we have lost a great champion of amphibians, Dr. Phil Bishop. He passed away on Saturday, January 23rd in New Zealand. All of us at AmphibiaWeb mourns the loss of our reliable ally and friend, an energetic scientist and tireless conservationist. Our heartfelt condolences to his family. The Amphibian Survival Alliance Secretariat, of which Phil was a member, articulates well our grief and our hopes in the face of this tragedy. Phil, you will be missed.
Phasmahyla guttata
Phasmahyla guttata by Mauro Teixeira Jr
January 18, 2021: A novel approach to biodiversity monitoring is the use of environmental DNA (eDNA) to detect species that once were present but have seemingly disappeared. Lopes and colleagues (2020) searched for 30 target species at six sites (e.g., Estacao Biol Boracia, Parque Nac Itatiaia) in the Atlantic Forest and adjacent Cerrado of southeastern Brazil using eDNA techniques on 62 water samples. The target species were considered to be declining (noticeably below historical levels), locally disappeared (not seen at sites in the last 10 years) or disappeared (not seen throughout their range for 10 years or more). The researcher successfully detected four declined species (Hylodes ornatus, H. regius, Crossodactylus timbuhy, Vitreorana eurygnatha), two locally disappeared species (Phasmahyla exilis, P. guttata) and one species not recorded since 1968 (Megaelosia bocainensis). The potential of eDNA in resurveys and monitoring is likely to be significant and may become an important method in the future. (DW)
Eurycea arenicola
Eurycea arenicola by Bryce Wade
January 11, 2021: The Eurycea bislineata complex ("Two-lined salamanders") is found in eastern North America from Quebec to the Gulf of Mexico and as far west as the Mississippi River. Prior to 2020, the complex consisted of six species, but several studies have shown the potential for more species in the complex. The most recent molecular analyses by Stuart et al. (2020) identified a seventh new species, Eurycea arenicola, split from E. cirrigera. The new salamander is found in the Sandhills of North Carolina, where it had long been considered a distinct ecomorph or candidate for full species because of its unique orange to red color with black spots and its unique habitat. In the Carolina Sandhills, it lives in slow-moving blackwater streams rather than flowing rocky streams along with other threatened species of this restricted ecosystem of longleaf pine and wiregrass like the Pine Barrens treefrog (Hyla andersonii). Analyses by Stuart et al. also indicate a complex gene exchange history as the most closely related species in their mtDNA analysis were more distantly related in their nuclear DNA analysis and the most geographically close population was not closely related by either analysis. The Eurycea bislineata complex still has more answers to reveal, but this study helps our understanding of a decades long question. (AChang)
Notophthalmus viridescens
Notophthalmus viridescens by Todd Pierson
January 4, 2021: Emergent fungal pathogens are endangering amphibian biodiversity. What happens when multiple pathogens infect the same host? McDonald and collaborators (2020) compared transcriptomic responses to coinfection by the two chytrid fungi Batrachochytrium dendrobatidis and B. salamandrivorans in several organs of Eastern newts. In combination with previous susceptibility trials (Longo et al. 2019), findings from this transcriptomic study suggest that coinfection by Bd and Bsal compromise immune function and could lead to increased mortality. Such impairment may be common in situations where hosts face multiple novel pathogens, and is siren of future biodiversity crises fueled by emergent diseases. (ACatenazzi)


back to News by Year
Necturus moleri by Kevin G. Hutcheson
December 28, 2020: As we approach the end of 2020, we are thankful for survival in the time of a global pandemic and the prospect of a better 2021. A bright spot was the milestone AmphibiaWeb reached in February 2020, the 20th anniversary! Our three primary founders are still closely associated: AmphibiaWeb Programmer Joyce Gross, Associate Director Vance Vredenburg, and Director David Wake. The AmphibiaWeb Team has been invigorated by the addition in recent years of a number of dynamic and contributing members, all of them working research scientists (Meet our Team). These dedicated Team members meet nearly weekly for a technical meeting. And we are holding special strategic planning sessions about every six weeks for more formal action and new initiatives. In fact, a lot of new organization and updates to content has been happening behind the scenes at AmphibiaWeb this past year, which will be unveiled in 2021. Meanwhile, enjoy a photo of the new species Necturus moleri from Southeastern US (5 of the 158 new species this year are from the US). We wish you and your family a safe, healthy, and happy holiday!
Thorius aureus by Sean Michael Rovito
December 21, 2020: Salamanders differ from all other vertebrates in their range of genome size. At the lower end (about 9 picograms (pg)/haploid genome) they marginally overlap with frogs but the upper end is vastly greater and exceeds 100 pg. Because cell size is proportional to genome size, salamander cells can be enormous and this poses a problem for small species, which often show bizarre morphologies. This led to the concept of biological size, as contrasted with metrical or physical size. A study of tropical plethodontid salamanders (Decena-Segarra et al 2020), many of which are very small, reports genome sizes and calculates biological size (mean snout-vent/square root genome size) for 84 species, 60 newly studied. Many of these species are biologically smaller than their physical size would suggest. Biological size may be the most effective measurement for studying morphological consequences of miniaturization in taxa such as Thorius and Batrachoseps. (DW)
Thoropa taophora by Mauro Teixeira Jr
December 14, 2020: Animals have many mating systems ranging from polygamy of one or both sexes to monogamy. Until recently polygyny, involving a male with several females with mate fidelity, had not been observed in amphibians. New observations from de Sá et al. (2020) change that with their description of how Thoropa taophora males guard rare breeding sites in rock seeps over an extended period of time where they exclusively breed multiple times with two or more females. Adding to the complexity of this breeding system, females appear to display a hierarchy with the dominant female mating more often and laying more eggs in the breeding site. The authors hypothesize that the same causes of polygyny in other systems, the severe limiting of breeding sites and intense intrasexual competition for mates, accounts for the development of this mating system in Thoropa taophora. (AChang)
Oedipina alleni by Vide Ohlin
December 7, 2020: The fourth clade of Lissamphibia (the modern amphibians), the Albanerpetontids, were the longest lasting of them all, originating in early Triassic and living with Hydromantes salamanders in northern Italy as recently as the mid-Pleistocene. What was thought originally to be the earliest chameleon, 99 million year old inclusions in amber from Myanmar, are in fact the best-preserved albanerpetontids, the new species Yaksha perettii (Daza et al 2020). These early amphibians independently evolved a ballistic tongue analogous to that of chameleons and featured a long entoglossal element, which likely remained in the floor of the mouth as the fleshy tongue slipped off its end as it fired at its prey. There is evidence that albanerpetontids were mainly small fossorial creatures with scales on toes with an armored head and body; the fact that they were captured in amber makes it likely they ventured into arboreal habitats to forage, as is the case in some tropical burrowing plethodontid salamanders like Oedipina (see Wake 2020 commentary). It is intriguing to imagine these small, secretive animals surviving somewhere in what remains of unexplored wilderness to the present time! (DW)
Neobatrachus sudellae by Kerry Kriger
November 30, 2020: While common in plants, whole genome duplication, or polyploidy, is rare in animals. The animals that are polyploid tend to reproduce asexually. Notable exceptions in the amphibian world that display both polyploidy and sexual reproduction, include members of the Xenopus genus and Bufotes viridis complex. Novikova et al. (2020) investigated another system in the Australian genus Neobatrachus, where six members are diploid and three are tetraploid, to better understand the evolutionary role of polyploidism. They found asymmetric gene flow from the more isolated diploid species to tetraploids, which have wider distributions, as the origin of the polyploid species. Furthermore, these inter-specific hybrid tetraploids displayed more wide-spread gene flow and were more tolerant of climate-induced habitat loss, providing a potential rescue effect to species diversity in the genus. (AChang)
Boana punctata by German Chavez
November 23, 2020: A new study by Taboada et al (2020) describes how dozens of frog lineages have independently evolved green coloration, but not through the typical route using skin cells containing pigments (chromatophores). Instead, these frogs have convergently co-opted serpin proteins to capture biliverdin, a cyan pigment that is a common by-product of the breakdown of hemoglobin in red blood cells. Using mass-spectrometry and spectrophotometry, Taboada and colleagues determine that green coloration of many frogs is conferred by three characters: 1) relatively clear skin, which allows for the visibility of 2) yellow pigments (hyloins and carotenoids) and cyan-colored serpin-bound biliverdin in subcutaneous lymph fluid. These pigments selectively absorb green and red light that is reflected by 3) a reflective basal tissue layer containing guanine crystals. The spectral reflectance of frogs that use biliverdin-based coloration, such as many glass frogs and hylid treefrogs, likely allows them to effectively camouflage against a green-leaf background. Independent origins of biliverdin-based coloration in frogs may have resulted from independent recruitment of different serpin genes. Future studies of serpin evolution in these frogs require more genetic resources to fully understand. (RDT)
Plethodon jordani by Bill Peterman
November 16, 2020: To improve predictions for how species will respond to our changing climate, we should not neglect the behavioral consequences of climate change. Gade et al. (2020) set out to address this shortcoming: they wanted to project how the changing conditions of the next century will influence salamander surface activity. They conducted surveys of three species of the Plethodon jordani complex in the Appalachians of the US, identified predictors of salamander surface activity and abundance (temperature and water vapor pressure), then used this relationship to explore how the surface activity of P. jordani complex species will respond to stabilization and high emissions climate scenarios. They found that the probability of salamander surface activity during peak active season increased over time, though gladly temperatures were not predicted to surpass the species' thermal maxima. Surface activity is important to salamanders because it their opportunity to forage and mate, so this outcome may sound like good news. However, the authors qualify that there are physiological trade-offs at play, so modified behavioral patterns can have unpredictable consequences. For example, higher temperatures increase metabolism and may decrease the energy assimilation of salamanders, which can result in smaller body sizes and lower growth rates, and in turn, result in delayed sexual maturity and lower fecundity. The authors show how the examination of behavior like surface activity, critical to their fitness, can reshape our understanding of how species will fare with a changing climate. (Emma Steigerwald)
Hyla versicolor by Jack Phillips
November 9, 2020: The physical properties of our environments greatly affects how all organisms interact with the physical world. The surface tension of water is no exception. Schwenk and Phillips (2020) show that surface tension can actually prevent small tadpoles from breaching the surface of water to breathe air. Instead, tadpoles perform a newly described form of air-breathing they call "bubble-sucking", during which tadpoles carefully suck down a bubble from the water’s surface. As tadpoles grow, they are eventually able to overcome this constraint and begin breaching the surface to breathe. Phillips et al. (2020) report that Gray Treefrog tadpoles (Hyla versicolor) do not follow these trends, and instead bubble-suck throughout ontogeny, even after they are large enough to breach the surface. They found that tree frog tadpoles not only never breach, but after growing to a certain size, begin breathing with a novel form of bubble-sucking the authors coin "double bubble-sucking". Double bubble-sucking includes an extra breathing cycle which appears to greatly increase the efficiency of air-breathing by separating freshly breathed air from the residual air already in the lungs. The authors find that tree frog tadpoles transition from normal bubble-sucking to double bubble-sucking at the same body size that the lungs suddenly become well-vascularized, suggesting the change in breathing mechanics is linked to a change from non-respiratory air-breathing to respiratory air-breathing. Check out media coverage of these articles in Sciencedaily and Popular Science. To learn more about tadpoles, see the 1st International Symposium on Tadpole Evolution, this week Nov 11-13th. (Jack Phillips)
Scinax perpusillus by Gui Becker
November 2, 2020: Global climate warming not only threatens individual species, but also disturbs entire ecosystems. Greenspan et al. (2020) report how warming effects on ecological communities influence the animal gut microbiome, a group of microbes that helps animals stay healthy. They set up miniature aquatic ecosystems with tadpoles (Scinax perpusillus), bacteria, worms, mosquito larvae, and other insects within water-holding tropical plants called bromeliads and exposed them to a warming gradient. They found that warming altered community assembly and species interactions within the ecosystem - for instance, which species were present and likely feeding on one another - and that these changes compromised gut microbiome health in tadpoles, leading to reduced fitness. These findings suggest that the vertebrate microbiome is sensitive to the many ways that climate change alters the structure and functions of ecological communities. Check out media coverage of this article in The Conversation and the Nature Research Community. (Sasha Greenspan)
Rana temporaria by Kristel Schneider
October 26, 2020: Amphibians of high elevation mountain lakes face many threats: climate change, novel pathogens, development, and overexploitation; however, the presence of non-native fish is the most significant. A study in the Pyrenees (Miró et al 2020) found rapid natural recovery of amphibian communities when non-native fish were removed from eight study lakes and compared them to 56 nearby control lakes with and without fish. The fish-removal lakes achieved natural richness levels one year after fish removal began, and typical species abundances after three years (with the only exception of Rana temporaria). Colonization of removal lakes occurred only from residual populations in the same valley. This study provides another example that montane amphibian communities can recover rapidly after eliminating or reducing non-native fish, and bolsters this technique to help other endangered amphibians in similar habitats. (VV)
Ranitomeya sirensis by Evan Twomey
October 19, 2020: Many members of the Peruvian poison frog genus Ranitomeya show a wide variety of color patterns, and two or more color morphs can exist within a single species. R. sirensis has yellow stripes over most of its range, but has a deep red color in the Sira mountains near the Brazilian border. Twomey et al. (2020) investigate this divergent coloration to determine the nature of the pigments in the skin of these frogs and the patterns of gene expression underlying pigment processing. First, with chromatography, they identified the carotenoid pigments in the skin and liver. As in previous studies, they found carotenoids associated with yellow coloration in both morphs (with a substantially higher amount in the red morph), as well as a number of ketocarotenoids in the red morph. These are modified carotenoids associated with red coloration. They then found in genetic tests that the red morph expresses a dysfunctional form of beta-carotene oxygenase 2 (BCO2: a carotenoid cleavage enzyme), which normally degrades carotenoids. This allows carotenoids to build to higher concentrations in the red morph, consistent with the results of their chromatographic analyses. They also found significantly higher expression of a carotenoid ketolase (CYP3A80: a cytochrome P450 enzyme) in the livers of red morph frogs. This appears to be the key enzyme converting carotenoids to ketocarotenoids, hence giving the red morph its distinctive appearance. By combining chemical analyses of pigmentation with genomic analyses of gene expression, this study bridges the gap between genotype and phenotype, a key goal of evolutionary analysis. (KSummers)
Litoria daviesae by Kellie Whittaker
October 12, 2020: Monitoring wildlife is a critical part of conservation. Understanding which species are present in an area allows researchers to prioritize areas for conservation and track the trajectory of vulnerable populations. One challenge associated with monitoring amphibians is the low detectability of some threatened or secretive species. To address this problem, researchers have recently applied a new technique that looks for amphibian host DNA in the meals of their invertebrate parasites or scavengers. This technique – termed invertebrate-derived DNA, or iDNA – was tested at a site in Australia using frog-biting midges (Cutajar and Rowley 2020). Researchers compared this technique to more traditional survey-based monitoring methods. iDNA was able to detect three species also detected by traditional methods but did not detect five species found with traditional surveys. However, at some sites, iDNA was able to detect species not recorded during traditional surveys, including some threatened species. This cost-effective and non-invasive survey technique could be a powerful new tool for monitoring amphibians and could aid in the detection of imperiled species. (AByrne)
Rana sierrae by William Flaxington
October 5, 2020: The endangered Sierra Nevada Yellow-Legged Frog (Rana sierrae) has generally been viewed as a lake species, but it also occurs in streams, yet in those habitats, there is little knowledge of its basic ecological requirements. Brown et al (2020) investigated the demography, habitat use, and movements of 12 stream populations of these frogs using multiple techniques (e.g., capture–mark–recapture and radio-tracking of adults, quantitative description of stream channel and riparian vegetation, frog habitat use, and egg masses counts). Stream populations varied in size (< 15 - 547 adults), and were found in diverse headwater streams. Frogs moved little over four-day survey periods, but were capable of moving longer distances of up to 1.2 km over the summer. This study provides important basic ecological requirements from overlooked populations of a species and reminds us that understanding a species complete natural history is critical to conservation and management efforts. (VV)
Taricha granulosa by William Flaxington
September 28, 2020: Dangerously poisonous newts (Taricha granulosa), which sequester the toxin tetrodotoxin (TTX), and predatory garter snakes (Thamnophis sirtalis), which can evolve TTX resistance, are engaged in a classic coevolutionary arms race. While generally roughly matched, in western Oregon and Washington other factors are important. While local adaptation dominates, a study (Hague et al. 2020) of geographic variation found that toxin levels are clearly predicted by the phylogeographic population genetic structure of newts and by factors in local environments. Still, predators have higher levels of resistance than the toxins of co-existing newts, suggesting intense selection. What at first seems to be intense arm race coevolution is shown to be a landscape level pattern-- a geographic mosaic of coevolution based on a mixture of often intense natural selection as well as demographic and environmental effects. This study enriches our understanding of this fascinating phenomenon, which is taking place over a large expanse of time and space. (DW)
Pipa pipa by David C. Cannatella
September 21, 2020: Most research on parental care has focused on mammals and birds; however, increasingly amphibian parental care has been in the spotlight, and Schulte et al 2020 chronologically reviews 685 papers providing an opportunity to highlight early contributions and summarize the body of study on the evolution, ecology, and physiology as well as the conservation implications of amphibian parental care. Remarkably amphibian parental care studies go far back in time; the first known observation of amphibian parental care was made by Maria Sibylla Merian in 1705, who witnessed and drew an image of a Pipa pipa giving birth to froglets from her back. Their review is organized phylogenetically and by the various modes of parental care found in amphibian orders. The authors point out an unsurprising bias of frog-focused studies-- much of the work done to date has focused on Neotropical poison frogs (dendrobatids and aromobatids)-- but highlight parental care studies in caecilians and salamanders and emphasize the value of pursuing research on parental care in a diverse set of amphibian taxa. Finally, they provide their view of key future directions for the field, including the value of multidisciplinary approaches and collaborations, the importance of integrating experiments of proximate mechanisms (i.e., physiological, endocrinological, spatial, genetic, behavorial, and ecological studies) into studies of evolution and adaptation, how parental behaviors impact amphibian declines, and the importance of continuing to understand the natural history of amphibian behavior. (KSummers)
Osteocephalus taurinus by José M. Padial
September 14, 2020: Effective conservation management plans depend on accurate knowledge of biodiversity, such as the number of species occurring in a region, which can be challenging for a variety of reasons. This is particularly true of Amazonian biodiversity where taxonomic uncertainties are common. Vacher et al. (2020) demonstrate a new approach to estimating biodiversity by analyzing a large dataset of geotagged frog DNA samples from Amazonia with a focus on the Eastern Guiana Shield to identify bioregions and regional endemism. Their next-generation sequencing and modeling results indicate that the number of bioregions and endemic species is severely underestimated. The authors estimate that, rather than the traditional range of 427 - 577 species, the Amazon contains at least 2,000 species of frogs. (AmphibiaWeb has a tally of 1,076 frogs in Brasil alone.) Furthermore, many of these species are likely threatened with habitat loss. The results from this analysis raise concerns about using meta-analyses based on public databases of Amazonian species and other poorly known groups. (AChang)
Chiropterotriton melipona by Sean Michael Rovito
September 7, 2020: The tropical plethodontid salamander genus Chiropterotriton is a clade of generally small, terrestrial, arboreal or cavernicolous species restricted to eastern Mexico. A 1983 revision listed nine species. A 2020 study (Parra Olea et al 2020) names five new species, bringing the total currently recognized to 23, most recently named and with restricted geographic distributions. As a group, these salamanders are at great risk of extinction, with 10 listed as Critically Endangered, 6 Endangered and 1 Vulnerable. Of the remainder, only one (Near Threatened) has been evaluated, but three of them are apparently safe at present. These are among the northernmost of the tropical plethodontids and those near the northern limits (states of Tamaulipas and Nuevo Leon) seem to have the most robust populations. Several of the more southern species (from the states of Hidalgo, Puebla and Veracruz) have witnessed dramatic declines in the last 30-40 years, probably from a combination of chytrid infection and habitat modification. (DW)
Sclerophrys gutturalis by Miguel Vences
August 31, 2020: Despite ample evidence of the negative effects of parasites on amphibians, little is known about the majority of them. Netherlands et al. (2020) shed some light on this with the description of a new genus and species of filarial (roundworm) nematode, Neofoleyellides boerewors in South Africa. The parasite was found in Guttural Toad (Sclerophrys gutturalis) and Garman's Toad (Sclerophrys garmani) with transmission from two mosquito vectors, Uranotaenia (Pseudoficalbia) mashonaensis and Uranotaenia (Pseudoficalbia) montana that preferentially sought out calling male toads. Surprisingly, while only male Guttural Toads were found to be infected, only female Garman's Toads were found to be infected with total infection rates of 13.5% and 6.7% respectively for each group. In lighter parasite loads, N. boerewors was found in the body cavities of toads. However, in highly infected toads, the parasite could be found subcutaneously, in the lymphatic tissue, and, in one disturbing case, in the host eye. Highly infected toads also had enlarged spleens, gallbladders, and livers, and had darker than normal external coloration. The individual with a parasite in the eye also appeared to lose vision in the eye as well as having swelling, infection, and internal bleeding of the eye. Despite this extreme case, the specific pathological effects of the parasite on the two species of Sclerophrys has yet to be determined. (AChang)
Womack and Bell 2020
August 24, 2020: Body size varies widely among animals and can affect physiological, ecological, and life history traits. Yet, surprisingly little is known about body size evolution within the most diverse amphibian order, anurans (frogs and toads). Womack and Bell (2020) examined anuran body size (snout-vent length) evolution among 2,434 species with over 200 million years of shared evolutionary history. The researchers found shifts in body size over evolutionary time with many independent evolutionary events of anuran miniaturization and gigantism, despite the upper limits of anuran body size remaining quite consistent throughout the fossil record. When analyzed in relation to latitude, elevation, microhabitat, and other factors, anuran body size does not conform to geographic and ecological patterns observed in other tetrapods and is perhaps more notable for variation in body size within geographic regions, ecologies and life histories. (MWomack)
Salamandra salamandra by Axel Hernandez
August 17, 2020: The pathogenic amphibian fungus known as Bsal (Batrachochytrium salamandrivorans) may be the most potent amphibian disease and poses extreme risk to natural populations, especially in salamanders. First detected in Fire Salamanders (Salamandra salamandra) in extreme southeastern Netherlands and adjacent Belgium and reported in 2013, it has spread to western Germany (with new reports from Bavaria), where it is having devastating effects. An entire issue of the journal Salamandra (2020, vol 56, issue 3, open access and available as PDF) is devoted to Bsal research centered in Germany. Salamander populations have essentially disappeared from the northern Eiffel region and are threatened in the southern Eiffel and Ruhr regions. Bsal has been present in Germany for at least 16 years and has been found in laboratory populations of the Common Frog, Rana temporaria, and field populations of the Great Crested Newt, Triturus cristatus. It is known to infect salamandrid species from southeast Asia, which appear to have been the source of the European outbreaks via pet trade importation. The goal in highlighting this important set of papers as stated by the editors "must go beyond documenting declines towards understanding spatio-temporal disease dynamics and the factors influencing the spread and impact of Bsal in different situations." In light of the seriousness of the Bsal threat in Germany, the authors' common goal is a national Bsal Action Plan, which would be of great importance for the international community of amphibian biologists and for the public. (DW)
Dendropsophus sarayacuensis by Mauro Teixeira Jr
August 10, 2020: The jumping power of frogs varies widely. Differences might be mediated by size or by microhabitat specialization or both. Mendoza et al. (2020) examined 68 species, including frogs that display phylogenetic, microhabitat and body mass diversity. High jumping power may have arisen near the base of the anuran phylogeny and the ability to apply high muscle-mass-specific power has likely been lost secondarily or reduced at least once. They found as body mass increased jumping power decreased. Burrowing species showed lower jumping power. Jumping power declines more rapidly with body mass in burrowers than non-burrowers. This suggests a functional trade-off between jumping and burrowing performance. Perhaps surprisingly, arboreal species, which were predicted to be more adept at amplifying power, were not. The authors think that future studies should consider the material properties required for utilizing elastic energy as well as temperature effects. (DW)
Rana muscosa by William Flaxington
August 3, 2020: Ford et al. (2020) synthesize the progress towards understanding threats to amphibians and outline a framework for advancing amphibian conservation. Numerous potential drivers of declines have been explored over the years, with some causes like UV-b radiation, acid rain, and limb deformities ultimately being unsubstantiated. Interestingly, while habitat loss and degradation are likely the largest drivers of amphibian declines, little work has actually directly explored the effects of these threats on global amphibian declines. Critically, most declines are likely the result of additive or interacting effects of multiple threats, and yet these multifarious effects are rarely considered. For example, in the Sierra Nevada of California, Yellow-legged frogs (Rana muscosa and R. sierrae) initially declined due to introduced trout predation and then subsequently were impacted by disease. In general, widespread pathogens like the amphibian chytrid fungus (Batrachochytrium dendrobatidis) are unlikely to be the primary cause of decline but likely often impact populations after other environmental changes or stressors has taken hold. Perhaps most importantly, while we have a wealth of information on possible threats to amphibians, the evidence for solutions to these problems are relatively limited. Ultimately, effective policy from local to national and international scales must incorporate amphibians explicitly if conservation efforts are to be effective. (MLambert)
Desmognathus quadramaculatus by Todd Pierson
July 27, 2020: The desmognathine plethodontid salamanders have undergone an adaptive radiation in eastern North America. First branching members of the clade are all terrestrial, but most species have returned to semiaquatic life and have re-evolved aquatic larvae. Some species have long, multi-year larval stages, but most have short, single-season larvae (eg., Black-bellied Salamander, Desmognathus quadramaculatus). Weaver et al. (2020) examined the climatic niche evolution in the clade and found that species with short larval periods show the greatest variation in thermal physiology, which is associated with distribution. Climate in the area has been unstable through space and time. Taxa with short larval periods may be able to better exploit a wider diversity of climates, which may promote species formation and long-term persistence of lineages. In turn, such forms may prove to have better resistance to extinction during periods of rapid climate change. (Read more in a digest from Lu 2020.) (DW)
Spea hammondii by Adam G. Clause
July 20, 2020: Habitat loss and degradation are the greatest causes of amphibian declines globally. A commonly proposed solution is to create artificial habitat – such as "mitigation" ponds - which can act as substitute habitat for amphibians displaced by habitat loss. But how well do they work? Baumberger et al. (2020) tested longterm success of created habitat by resurveying 21 mitigation ponds ten years post-construction and ten natural ponds impacted by urban development in southern California. They found that the artificial ponds maintained the adequate hydroperiod to sustain Western Spadefoot Toads (Spea hammondii), the species these ponds were targetting. Critically, western spadefoot larvae and embryos had been translocated to these ponds a decade earlier and many ponds still host populations which not only successfully breed but also metamorphose. These artificial habitats serve an important role because surveys found these toads are now entirely absent in the urban landscape they used to exist in. Given Western Spadefoot Toads are an IUCN Near-Threatened species, a California Species of Special Concern, and are under review for listing under the U.S. Endangered Species Act, knowing that created habitat is a successful conservation tool is critical for their conservation. Importantly, southern California is experiencing tremendous effects of climate change and these ponds were impacted by drought but provided western spadefoots a buffer against the effects of climate change. If designed correctly, artificial habitat can be a useful tool to buffer amphibian declines from both habitat loss and climate change. (MLambert)
Excidobates mysteriosus by Brian Freiermuth
July 13, 2020: Amphibians have evolved various breeding behaviors to maximize fitness; one example is to breed in plants that have collected rainwater, or phytotelma-breeding, which reduces competition and predation. An apparent contradiction of the benefit of this behavior is that there are not more evident adaptive radiations of phytotelma-breeding species in the Neotropics. Tonini et al. (2020) examined this phenomenon by mapping breeding behaviors on a neotropical frog phylogeny. They found at least 14 phytotelma-breeding origins across 10 families with 115 instances of breeding behavior reversal, indicating that phytotelma-breeding behavior is flexible. Their results also indicate that while phytotelma-breeding did not constitute a major ecologically-mediated adaptive radiation, with the exception of bufonid species (toads), lineages with phytotelma-breeding origins had a slightly higher net diversification rate than pond or stream breeding lineages. The cause of this pattern needs further investigation, but phytotelma-breeding may be a surrogate for other variables that affect Neotropical frog diversification. (AChang)
Rana sevosa by Jake Hutton
July 6, 2020: The Dusky Gopher Frog (Rana sevosa) is an IUCN Critically Endangered species native to the southern Coastal Plain of the United States, but which has been reduced to only one known population. Several measures have been adopted to conserve the species including captive breeding with artificial fertilization paired with reintroductions. Roznik and Reichling (2020) evaluated reintroduction methods for the species to maximize these efforts by radio-tracking released individuals. They found relatively high survival rates (76%) for released juveniles with higher survival rates for individuals released near burrows in fire-maintained habitats than individuals released near ponds. On average, individuals released near ponds also traveled further, likely reflecting their longer search for suitable shelter. Sheltering underground improved survival rates by 22%. Although long-term monitoring is still needed, these findings provide optimistic evidence that artificial fertilization and captive rearing has minimal effects on the species' ability to successfully transition to native habitat as long as suitable fire-maintained, open-canopy long-leaf pine forest habitat is available. (AChang)
Rana (Lithobates) vibicaria by Robert Puschendorf
June 29, 2020: Outbreaks of the infectious disease chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), are implicated in the decline and extinction of numerous amphibian species, especially in the Americas. In Costa Rica, a major decline event occurred in 1987, more than two decades before this pathogen was discovered. Vredenburg et al (2020) used a quantitative PCR assay to test for Bd presence in 1,016 museum specimens of frogs collected throughout Costa Rica, which included many Critically Endangered species. The earliest specimen that tested positive for Bd was collected in 1964. The number of infected individuals remained relatively low across all species tested, and the range of Bd-positive specimens was shown to be geographically constrained up until the 1980s when epizootics are hypothesized to have occurred. After that time, infection rate increased three-fold, and the range of specimens tested positive for Bd increased, with Bd-positive specimens collected across the entire country. Our results suggest that Bd dynamics in Costa Rica are more complicated than previously thought and warrants further investigation. These data are archived at AmphibiaWeb's repository. (VV)
Hydromantes platycephalus feeding by Stephen Deban
June 22, 2020: Plethodontid salamanders use protrusible, ballistic tongues that display high performance and work well in both cold and warm temperatures to capture prey. Deban et al (2020) show in a musculoskeletal and performance analysis that remarkable homoplastic evolution in the two major groups of plethodontid salamanders has transformed a muscle-powered, musculoskeletal system capable of only modest performance and subject to thermal sensitivity into an extreme-performance, spring-powered system that is thermally robust. Extreme examples exceed available muscle power using an elastic-recoil mechanism. Intermediate forms are not found, suggesting that incipient elastic forms maybe short-lived. The result is a rich array of functional patterns of tongue use in feeding, with remarkably specialized end points. (DW)
Chimerella mariaelenae by Alberto Sanchez-Vialas
June 15, 2020: Glass Frogs of the family Centrolenidae occur throughout the American tropics, from southern Mexico to southern Brazil, Bolivia and Peru. Currently about 160 species are recognized in 12 genera. In a detailed review of the 60 centrolenid frog species in Ecuador, Guayasamin et al. (2020) names three new species and identifies an additional 24 candidate species. The frogs are commonest in wet habitats in both eastern and western montane and foothill forests. They evaluate the conservation status of all these frogs and identify likely candidates for extinction. Glass frogs are renowned for their transparent skin that make their green bones, intestines, and beating hearts visible to the naked eye. Barnett et al. (2020) argues that these frogs are translucent, imperfectly transparent, because of sparse dorsal pigmentation, sometimes mimicking eggs laid on leaves and guarded by males. In their study, passive changes in luminance was most dramatic in the legs of the frog, creating an "edge diffusion" effect that avoids high-contrast edges and allows the frogs to better blend into their backgrounds. Paired with the fact that glass frogs spend most of their time on green leaves, this edge diffusion is an effective camouflage technique for glass frogs distinct from true transparency or active color change found in other animals. (DW & MWomack)
June 8, 2020: Fossil frogs have long been expected from Antarctica, holdovers from a Gondwana distribution that must have united proto-South America with proto-Australia/New Zealand/New Guinea. At last they have been found (Mörs et al 2020), in Eocene age rocks from Seymour Island off the east shore of the Antarctic Peninsula. The identity of the frogs, represented by scant remains of an ilium and a fragment of skull roof, is a surprise – Calyptocephalella, a genus represented today by a relatively large, enigmatic single species from the wet temperate zone of Chile. However, the taxon is very old, predating the Cretaceous/Paleocene event, and it has a fossil record in southern South America. The Antarctic fossils were found in a community that included such angiosperms such as water lilies, some marsupials, indicating it was likely a moist, rich environment. Now it is time to find even older Antarctic frogs – they should be there! (DW)
Dendropsophus labialis by Giovanni Alberto Chaves Portilla
June 1, 2020: "Frogs call the water with their songs" and "Some people look for good luck numbers on the ventral spots of the frogs" -- these are some of the traditional beliefs in the Colombian Andes reported in a study by Rios-Orejuela et al (2020). Local communities maintain active relationships with their ecosystems, which is essential to conservation efforts. Colombia possesses one of the highest biodiversity of amphibians and reptiles in the world, and the Andean region of the Reserva Forestal Protectora Cerro Quininí is one of the most important ecological corridors in the northeast Andes and 90% of the reserve is shared with the local community. The authors surveyed 61 inhabitants in the region about their academic knowledge, use and cultural beliefs, and interaction with the herpetofauna. The survey found that the local community recognizes the particular habitat for each type of animal (e.g., frog, lizard), which could help identify conservation hotspots. Most of the inhabitants do not recognize any traditional or medical use for these animals, even though the reported uses are diverse. Finally, in general, the interaction with this herpetofauna is either neutral or positive. However, the inhabitants located in rural areas interact in a more positive or neutral way compared to the urban inhabitants. This study highlights the necessity for greater efforts in dissemination and scientific communication that allow the local community to get involved and contribute in more concrete and effective ways in the management and conservation efforts of the herpetofauna of the region. (Valeria Ramirez Castaneda)
Atelopus mindoensis by César L. Barrio Amoros
May 25, 2020: Harlequin toads (genus Atelopus) have been hit particularly hard by the deadly amphibian chytrid fungal disease. This is especially true in Ecuador, where all 25 species of Atelopus found in the country are considered threatened or worse, and half have not been seen since the early 1990's. However, Barrio Amorós and colleagues (2020) report a 2019 rediscovery of Atelopus mindoensis in Ecuador providing a glimmer of hope for these imperiled amphibians. They describe finding five juveniles and two adults on a private reserve near Mindo. Two juveniles were analyzed for the presence of chytrid fungus and no signs of disease were detected. This exciting news adds to other examples of persisting Atelopus populations since 2008 in the face of ongoing disease threats and gives hope for the future of these magnificent frogs. Other rediscoveries include A. cruciger in Venezuela (Rodríguez-Contreras et al. 2008), A. varius in Costa Rica (González-Maya et al. 2013) and Panama (Perez et al. 2014), and A. longirostris in Ecuador (Tapia et al. 2017).(AByrne)
Litoria verreauxii by Eric Vanderduys
May 18, 2020: The capacity of Batrachochytrium dendrobatidis (Bd) to negatively impact amphibian diversity at the species and population level has been clear for decades, yet our understanding of Bd’s impact on amphibian genetic diversity remains unresolved. Banks et al (2020) compare SNP diversity in Bd-naïve alpine tree frog populations (Litoria verreauxii alpina) with populations exposed since the 1980s to help illuminate whether we should be concerned about the genetic viability of species that underwent major Bd-associated declines. Although most breeding adults in exposed populations still succumb to disease each year, Banks et al did not find significant differences in the genetic diversity of exposed and naïve groups. The study was limited by the few available naïve populations, but many frogs do manage to breed before they die, and juveniles can escape infection and provide a reservoir of genetic diversity. Individuals' heterozygosity correlated with infection likelihood in exposed populations, so the authors suggest that more heterozygous frogs may generally contribute more to the next generation. Finally, like many species heavily impacted by Bd, this alpine frog species occurs in isolated, low-density populations. They finds little genetic exchange between these remnants, concluding that sustained isolation will result in the further structuring of these populations into the future. (Emma Steigerwald)
Taricha granulosa by Heidi Rockney
May 11, 2020: Many salamandrids possess tetrodotoxin (TTX), the same neurotoxin found in pufferfish. Although TTX in marine animals derives from symbiotic bacteria or diet, the source in amphibians has been controversial. Populations of rough-skinned newts (Taricha granulosa) possess different amounts of TTX due to the evolution of TTX resistance in populations of predatory garter snakes. Vaelli et al. (2020) examined the skin microbiome in high- and low-TTX populations of newts and found that bacterial diversity was lower in the highly toxic population, suggesting their skin microbiota is tightly regulated. Several strains of bacteria, particularly Pseudomonas, cultured from the skin of toxic newts were shown to produce TTX in the lab, and Pseudomonas were significantly more abundant in toxic than non-toxic newts. The ability of rough-skinned newts to resist TTX appears to derive from mutations in the target of the toxin, voltage-gated sodium channels (NaVs); all six NaV genes possess mutations in the TTX-binding region of the channel, and electrophysiological experiments with the most widely expressed channel (NaV1.6) verify the mutations confer resistance to almost infinite concentrations of TTX. They show an important role that symbiotic microbes play in the physiology and evolution of their multicellular hosts. (Heather Eisthen and Patric Vaelli)
Ranitomeya imitator by John P. Clare
May 4, 2020: Neotropical poison frogs provide iconic examples of conspicuous warning coloration, yet we know very little about the biochemical mechanisms that underlie the production of these astonishing colors. Twomey et al. (2020) use a combination of spectral reflectance, chromatography, electron microscopy measurements, and simulations of coloration to identify key components of color variation in a mimetic radiation of the Peruvian mimic poison frog (Ranitomeya imitator) and related model species. They revealed that the mimic frog has a broader "palette" of colors than the models, which accords with their history of evolving to match the color patterns of other species. Surprisingly, however, the major proportion of variation did not appear to be in pigment types. Instead, the key variation occurred in the thickness of guanine platelets in a type of organelle called iridophores. The variation in platelet thickness appears to influence yellows and oranges, contradicting the traditional view that it should affect structural colors like blues and greens and hue (overall spectral reflectance). Their study provides insight into the underlying mechanisms enabling the evolution of both divergence and convergence in aposematic coloration in the Neotropical poison frogs, revealing novel mechanisms that may apply to other taxa as well. (KSummers)
Huia cavitympanum by Alexander Haas (ImageQuest3D)
April 27, 2020: Frogs and toads, known for their conspicuous calls often used to attract mates, generally follow the pattern of lower-frequency calls associated with larger frogs and vice-versa. This scaling relationship mainly results from physical law and appears to be fairly universal within and among species. Tonini et al. (2020) examined this relationship between body size and call frequency among 1,610 species and found this relationship fairly predictable across the frog tree of life. However, four groups (Poison frogs, Ranid frogs, Southeast Asian ranids, and Fitzinger Neotropical Tree frogs) call at higher frequencies than expected at larger body sizes. The reason these four clades deviate from the general scaling pattern remains unclear. The authors propose ultrasonic communication, visual signaling, differences related to calling, acoustic competition, and morphological changes in vocalization or hearing structures as hypotheses that need to be tested. However, for every explanation posed there appear to be exceptions. Thus, the drivers of anuran call frequency evolution at deep timescales are complex but body size imposes a clear and nearly universal constraint. (MWomack)
Litoria aurea by Philip de Pous
April 20, 2020: Habitat loss is the greatest threat to amphibians globally. Human activities that change the presence, abundance, and timing of water on the landscape are particularly harmful because most amphibians rely on water for at least part of their lives. Altered water availability can also favor introduced competitors and predators that harm amphibians. Biologists have long recommended that directly managing water availability could be important to conserving many species. Despite this common recommendation, a review by Mathwin et al. (2020) could only identify 17 published studies addressing the success of manipulating water. While the authors acknowledge several biases to why so few studies were detected, they identified important themes in the success of this management tool. One of the most common and successful water manipulations for amphibians was to increase hydroperiod (e.g., by creating new waterways, excavating ponds, damming flowing water, pumping, etc.). Doing so often increased the success of breeding and larval metamorphosis. Targeted drying to shorten hydroperiods also has been shown to be successful in removing predators that eat amphibian larvae or by removing introduced amphibians (e.g., American bullfrogs) which require permanent waterbodies. Spraying water onto land is thought to benefit amphibians by increasing available moist habitat but may have important costs such as facilitating the spread of disease or introduced, harmful amphibians. They highlight a number of positive outcomes of manipulating water availability for amphibian conservation but also identify the possibility of a number of predictable and unpredictable outcomes, too. More research, including publishing unclear or negative results, is critical for assessing how manipulating water benefits amphibian conservation. (MLambert)
Anotheca spinosa by Edward Stanley
April 13, 2020: While frogs are well known for having skeletons that are reduced with respect to other terrestrial vertebrates, the skeleton still exhibits substantial variation among frogs, especially in the skull. Using three-dimensional anatomical data, Paluh et al. (2020) quantified frog skull diversity across all living families to test for relationships among ecology, skull shape, and increased mineralization (known as hyperossification or dermal ornamentation). Hyperossification has evolved more than 25 times across the frog tree of life, and although it can be present in species of nearly all sizes and habitats, it often occurs in frogs with deviant skull shapes that are known to either prey on other vertebrates or use their head to fill cavities or block holes (a behavior called phragmosis). Hyperossification is present in some frogs not known to feed on large prey or use phragmotic behavior, and it is possible that the function of hyperossification in these species may be tied to osmoregulation. Frogs are often assumed to share a highly conserved skeleton, but the study illustrates substantial diversity across anuran skulls that is linked to varied functions. (Dan Paluh)
Litoria tyleri by Beat Akeret
April 6, 2020: AmphibiaWeb is saddened to announce the recent death of Michael J. Tyler, British-born biologist, who spent his adult life studying the frogs of Australia and adjacent regions, including Papua New Guinea. Mike Tyler conducted many notable studies, such as gastric brooding in Rheobatrachus silus. He authored more than 300 scientific publications including general books for the public on Australian frogs and field guides to the frogs of Australia, South Australia and Western Australia (his field guide to western Australian frogs with Paul Doughty is now in its 4th edition). He had long-term productive collaborations with Margaret Davies on frog anatomy, as well as with physiological colleagues on glandular secretions and chemical defenses of frogs. His many publications include numerous taxonomic studies leading to the descriptions of many new species (e.g., of Uperoleia, Cyclorana, Litoria). He long was concerned with the conservation of frogs. We will miss his collegiality and contributions. (DW)
Triturus carnifex by Joachim Nerz
March 30, 2020: A comprehensive assessment (more than 250 references) of how the application of evolutionary principles and approaches can improve conservation outcomes for amphibians (Pabijan et al. 2020) offers many examples and insights. A surprising number of negative effects can arise from invasive species and from introgression and hybridization, but there are also some known salutary effects. Although range fragmentation and reductions in effective population sizes can have many negative effects, it is also possible for populations to maintain genetic variability during long periods of isolation, giving hope for recovery. A table of evolutionary research questions of fundamental importance for amphibian conservation concludes this useful overview. (DW)
Taricha torosa by Sam Murray
March 23, 2020: Climate change is a growing threat to amphibians, in large part because of more frequent extreme heat and drought events. Using 10 years of survey and mark-recapture data, Bucciarelli et al. (2020) recently showed that populations of California newts (Taricha torosa) – a widespread species across California – have been impacted by extreme climate events in recent years, particularly in southern California where climate change is already more pronounced. Specifically, from 2008 to 2016, California newt body condition (body mass relative to newt length) decreased by 20% in response to extreme heat and drought. Newt survival also decreased over time in response to climate change. These effects were not seen in the northern part of the California newt’s range where climate change has been less pronounced. Even so, modeling suggests that climate change in northern California will be as severe or worse for newt populations. This work highlights the critical impact climate change will have on amphibian population declines and extinctions in the coming years, both on its own and also by exacerbating other serious threats like habitat loss and disease. (MLambert)
Proteus anguinus by Joachim Nerz
March 16, 2020: Blind, aquatic, and with a great sense of smell, olms (Proteus anguinus) are enigmatic amphibians that reproduce once every 12 years and live for over 100. In a recent study, Balázs et al (2019) surveyed a population of olms in Eastern Herzegovina for eight years to discover that over this timeframe, individuals rarely move more than a few meters. Amazingly, one individual did not move for over seven years. In the absence of any major predators, the high site fidelity of Proteus anguinus may instead be related to extreme pressures to conserve energy in low-nutrient cave habitats. Studies of olms in the wild are rare, and this study contributes to our understanding of how long-lived amphibians survive in such challenging environments. (RT)
Amnirana albolabris by Daniel Portik
March 9, 2020: New understanding of the development and evolution of the key innovation that makes a frog so recognizable is presented in a study by Senevirathne et al. (2020). The urostyle, a unique modification of the frog pelvis and posterior vertebrae, functions importantly in frog locomotion. The hypochord, a subnotochordal band of cells, which is transitory in salamanders and fishes (and apparently absent in caecilians), becomes associated during frog development with the transitory caudal vertebrae and coosifies with them to form the urostyle, along with elongated iliac rods that support the ischium in the pelvis. The new experimental work on a series of tadpoles, using clearing and staining coupled with several molecular and cell biology techniques, reveal the process of urostyle development, muscular and neuroanatomical modification, and the role of the hypochord in urostyle development and in signaling the bifurcation of the dorsal aorta, which has long been a mystery. (MWake)
Atelopus laetissimus by Nikki Roach
March 2, 2020: The greatest threat to biodiversity globally – including for amphibians – is habitat loss due to human land use. These threats may be particularly pronounced in the tropics. With over 800 amphibian species present, 372 of which are endemic, Colombia ranks second globally in amphibian species diversity and endemism. But Colombia is also the 3rd largest coffee producer and has other substantial agriculture. The country is also geographically diverse and many amphibians specialize on relatively narrow elevational ranges. Roach et al. (2020) recently found that land cover and land use, more so than elevation, are the largest factors shaping amphibian diversity and community structure in Colombia. Shade coffee in particular is the least suitable land type for amphibians. But even natural grassland habitats host relatively limited amphibian communities. Forests and transitional ecotone habitats between various natural and agricultural environments harbor the richest and most abundant amphibian communities. These transitional ecotone habitats between agricultural and natural landscapes will be critical to preserve and restore the diversity of microhabitats for amphibians. Their study highlights the need to work with diverse stakeholders and land owners to conserve landscapes and amphibian diversity. (MLambert)
Incilius alvarius by Glenn and Martha Vargas, California Academy of Sciences
February 24, 2020: Smoking the dried secretions from toads is known for its psychedelic effects and recent investigations indicate it may alleviate depression, anxiety, and symptoms of PTSD. Uthaug et al. (2019) sought to determine the sub-acute and long-term therapeutic applications of the dried toxins from the Colorado River Toad Incilius alvarius, which has high concentrations of the psychoactive compound 5-methoxy-N,N-dimethyltryptamine (or 5-MeO-DMT). The authors implemented a series of questionnaires before and after (up to 24-hour and again at 4-weeks post) a single inhalation of the substance in a naturalistic setting. Participants were more satisfied with their lives and had improved mental states immediately after their experience and these feelings were still present at the 4-week survey. Depression and anxiety decreased to a significant degree 4-weeks post exposure. Clearly investigations into 5-MeO-DMT for its therapeutic benefits continue to show promise. (AChang)
Ansonia albomaculata by Alexander Haas
Cochranella mache by Bert Willaert
Echinotriton chinhaiensis by Max Sparreboom
February 17, 2020: Twenty Years of Service by AmphibiaWeb— Since its official launching in February 2000, AmphibiaWeb has aimed to serve the community of amphibian biologists by providing up-to-date information concerning the relationships, identity, distribution and conservation status of all of the World’s amphibians. Key to the success of AmphibiaWeb has been the sustained support of the Museum of Vertebrate Zoology, especially its curatorial staff (at present Associate Director Michelle Koo and Senior Associates Carol Spencer and Rebecca Tarvin). Associate Director and Co-Founder Vance Vredenburg has been with AmphibiaWeb since its very inception. We have benefited from our close associations with international partners like Santiago Ron of BioWeb Ecuador through its Anfibios del Ecuador, JIng Che who runs AmphibiaChina 中国两栖类, and Alexander Haas and Indraneil Das of Frogs of Borneo. AmphibiaWeb looks forward to continuing its record of service for amphibians and their well-being.
Hemiphractus johnsoni by David Wake
February 10, 2020: AmphibiaWeb celebrates its 20th year— AmphibiaWeb launched in February 2000, and has grown steadily in use and features ever since. Our founding director David Wake continues to serve the project along with our original programmer Joyce Gross, while new team members provide value, experience and expertise, keeping us vibrant and active. Our core mission is unchanged: providing access to a full range of information on taxonomy, appearance, distribution, conservation status and the general biology of all amphibians. We are moving into new dimensions with for tracking the fungal diseases which continues to wreak havoc on amphibian populations worldwide. Stay tuned for new work on life history traits! AmphibiaWeb continues to highlight relevant news, track new species descriptions (formal designations average about three per week), and bring you the latest updates on phylogeny and conservation research. We look forward to serving the community for more decades to come and invite your participation. Contact us!
Alytes obstetricans by Alberto Sanchez-Vialas
February 3, 2020: As the result of improper disposal and high dispersal potential, microplastics (plastic particles less than 5 mm) can now be found worldwide. Microplastics have been shown to have negative effects on ecosystems, particularly in marine environments, but their effects on freshwater systems is still relatively unexplored. Two recent microcosm experiments focused on the effects of microplastics on tadpole fitness. Da Costa Araújo et al. (2020) found microplastics caused morphological change and had mutagenic and cytoxic effects in Physalaemus cuvieri that may lead to decreased growth and survival of the tadpole. Boyero et al. (2020) found that at low and medium microplastic concentrations, Alytes obstetricans tadpole growth and body condition decreased, while at high concentrations (1800 particles/mL), the majority of tadpoles died. Both of these studies illustrate that microplastics are a novel stressor to amphibians, have the potential of bioaccumulating in amphibians and to be transferred by amphibians from aquatic to terrestrial environments, and thus are worth further research and consideration in amphibian conservation. (AChang)
Plethodon montanus by Jake Hutton
January 27, 2020: Montane amphibians might be in essence "pushed" off the tops of mountains by climate warming. Lyons and Kozak (2019) compare the commonly used correlative approach (correlations between known localities and current environments) to modeling of geographic ranges of taxa now and in the future with a mechanistic approach of their own design, which incorporates species-specific physiology, morphology and behavior. The latter approach works best when applied to three montane species of Plethodon in the southern Appalachian Mountains of North America. The correlative approach could spuriously predict less future suitability. The mechanistic approach predicted more suitable future habitat than the former through 2085. The main factor distinguishing the two approaches appears to be related to the ability of the mechanistic approach to model shifts in key range-limiting biological processes. (DW)
Mantella laevigata by Alexandre Roland
January 20, 2020: Parenting is an uncommon strategy among amphibians to raise offspring, and rarely takes the form of intense care compared to other vertebrates. For example, when species diversified and gained new niches to avoid competition for the same resources, maternal provisioning provides evolutionary benefits to surpass the cost of reduced access to nutrients. Fischer et al. 2019 demonstrated that in addition to supplying nutrients to offspring living in small isolated pools of water, maternal provisioning of unfertilized eggs is a way of passing along chemical defenses in some aposematic and poisonous frogs species. This mechanism of toxin transfer convergently evolved in two distant clades of frogs living in the antipodes, the Malagasy Climbing Mantella (Mantella laevigata) and the Ecuadorian Little Devil Poison Frog (Oophaga sylvatica), which diverged roughly 140 million years ago. Further, they showed that the neuronal basis of their maternal behavior relies on similar brain region activities but with distinct activation patterns, suggesting an evolutionary versatility in the molecular mechanisms sustaining maternal provisioning. (Alexandre Roland)
Cornufer vitianus by Clare Morrison
January 13, 2020: Corticosterone is a glucocorticoid hormone associated with animal physiological stress responses, which in turn, are related to growth, survival, and reproduction. As a result, the hormone is often measured for ecological and conservation research. Narayan et al. 2019 recently reviewed the various methods of measuring corticosterone and their benefits and limitations. They advocate for non-invasive methods of measuring this hormone (such as urinary, skin and buccal swabs, and water-borne hormone monitoring) for amphibian conservation research because these non-lethal methods can be collected as a time series in the field with little handling, giving researchers a more complete picture of the potential sub-lethal effects of environmental stressors. To support their argument, they present two case studies on the effects of interspecies stressors in two threatened amphibian species, the Fiji Ground Frog, Cornufer vitianus (synonym Platymantis vitiana), and the San Marcos salamander, Eurycea nana, of Texas. (AChang)
Adelphobates galactonotus by Brian Freiermuth
January 6, 2020: Bright colors may serve to warn predators that potential prey are toxic, so one might predict that predators are the main factor driving diversification in warning signals. However, several studies of color polymorphisms in poison frogs suggest otherwise. In one study, Jeckel et al. (2019) found Adelphobates galactonotus from two localities with distinct color morphs did not differ in their toxin profiles or palatability. They suggest the color difference is unlikely to have evolved from predation pressures and instead be a product of parental imprinting and sexual selection, as was found in Oophaga pumilio by Yang et al. (2019) [News of the Week Nov 11, 2019]. In another, Rojas et al. (2019) reconstructed the evolution of color in >200 individuals of A. galactonotus and found that transitions between color morphs have occurred several times. Using mtDNA and a SNP matrix, they found population structure was mostly explained by geographic distance (not color), and that population sizes were relatively small. Rojas et al suggest that genetic drift likely played a role shaping the current diversity of colors in this species. Finally, a study by Lawrence et al. (2019) [News of the Week October 28, 2019] suggest that a suboptimal warning signal in Dendrobates tinctorius arose through drift. These studies mark a shift in how evolutionary biologists are thinking about signal diversity in toxic animals. (RT)


back to News by Year
Aneides klamathensis by Spencer Riffle
December 30, 2019: AmphibiaWeb wishes you a Happy New Year! We are closing 2019 with 145 new species making a grand total of 8,111 currently recognized amphibians. This is a little below the decadal average of 152 new species per year, but a 1.8% increase, mainly from new discoveries. AmphibiaWeb has been expanding and updating key sections. The Phylogeny and Taxonomy pages now leads with a Phylogeny Primer spearheaded by AmphibiaWeb team members Max Lambert, Molly Womack, and Rebecca Tarvin. This year, we also introduced a new family-level consensus phylogeny, which is an interactive way to browse all the amphibian families. In the new year, we will upgrade the Amphibian Disease portal and develop and integrate new trait data. As always, AmphibiaWeb will continue to monitor the state of the World’s amphibians and provide up-to-date information into the next decade by tracking new knowledge on amphibian biology, taxonomy, and conservation for every species in the world.
Pristimantis multicolor by Santiago Ron
December 23, 2019: The global community of taxonomists describes, on average, 150 new species of amphibians every year. But do these new species change our understanding of large-scale evolutionary patterns or are these just minor additions to the amphibian tree of life? Blackburn et al. (2019) use the temporal pattern of species descriptions over the past 250 years in combination with large scale evolutionary trees to understand whether species are added in predictable ways. The patterns of taxonomic maturation revealed by these analyses suggest groups of amphibians, reptiles, flowering plants, invertebrates and regions for which there remain opportunities for still discovering deep lineages that can contribute new understanding to evolutionary relationships and patterns. (DB)
Cornufer vitianus by Paddy Ryan
December 16, 2019: Corticosterone is a glucocorticoid hormone associated with animal physiological stress responses, which, in turn, are related to growth, survival, and reproduction. As a result, the hormone is often measured for ecological and conservation research. Narayan et al. 2019 recently reviewed the various methods of measuring corticosterone and their benefits and limitations. The authors advocate for non-invasive methods of glucocorticoid hormone measurements, such as urinary, skin and buccal swabs, and water-borne hormone monitoring, for amphibian conservation research because these non-lethal methods can be collected as a time series in the field with little handling, giving researchers a more complete picture of the potential sub-lethal effects of environmental stressors. To support their argument, the authors also presented two case studies on the effects of interspecies stressors in two threatened amphibian species, Cornufer vitianus (aka Platymantis vitiana) and Eurycea nana, providing useful and timely guidance for research. (AChang)
Bombina bombina by Bert Willaert
December 9, 2019: Not all animals have the same amount of DNA in their cells. Among tetrapods, amphibians are remarkable in their genome size variation. In amphibians, larger genome size has been linked to slower development and is hypothesized to impact the formation of late-developing traits like digits, lungs, and brain complexity. Although salamanders are stand-outs with the largest genome sizes in tetrapods (reaching >120 pg or picograms), frogs and toads also have a considerable amount of genome size variation (ranging from 0.95–19 pg). Recently Womack et al. (2019) found that genome size was positively correlated with larval development rate among 90 species, expanding on similar results from previous studies on fewer species. They show that frogs lacking the late-forming middle ear (a repeated evolutionary loss among anurans) often had larger genome sizes than closely-related eared species. They also found that earless species often have very small body sizes at metamorphosis. It could be that middle ear loss is related to slower development (as indicated by larger genome size) and/or developmental constraints related to larger cell sizes and smaller body sizes. Their work provides evidence that increases in frog genome size, although less drastic than those in salamanders, is correlated with the loss of a late-forming and seemingly important sensory trait. They provide a new clue for biologists trying to understand the perplexing evolutionary loss of frog middle ears. (MWomack)
Brachycephalus pitanga by Alberto Lopez-Torres
December 2, 2019: In diverse wildlife communities, exchange of pathogens and symbiotic bacteria among host species influences disease dynamics. The aquatic fungal pathogen Batrachochytrium dendrobatidis (Bd) has wiped out tropical frog communities, with unresolved declines even in terrestrial-dwelling frogs. Becker et al (2019) studied communities of tropical Brazilian frogs to explore spread of pathogenic and potentially beneficial microbes to the disease-susceptible terrestrial-dwelling pumpkin toadlet Brachycephalus pitanga. Toadlets acquired lethal fungal infections, but rarely acquired protective bacteria, from naturally infected aquatic frogs, with disease causing imbalances in host symbiotic bacteria. Our results suggest that pathogen transmission from mildly infected aquatic frogs may lead to death and disruption of symbiotic bacteria in vulnerable terrestrial species. (Gui Becker)
Cycloramphus fuliginosus by Felipe Toledo
November 25, 2019: In frogs, breeding in water is the ancestral condition. Yet terrestrial breeding has evolved repeatedly. Recently, de Sá et al (2019) found that terrestrial breeding in the Neotropical frog genera Cycloramphus and Zachaenus (family Cycloramphidae) has independently evolved three times. Terrestrial breeding is thought to have evolved as a way to escape threats to eggs and larvae from aquatic predators. This work shows that an equally important driver of terrestrial breeding could be the high costs associated with high male-male competition and guarding nest territories. They reason aquatic breeding species have limited nest sites in rocky streams, which leads to high competition among males for high-quality nest sites. Females are typically bigger than male frogs but increased male-male competition leads to selection for larger males, reducing the size differences between the sexes. By switching to terrestrial breeding, the higher abundance of sites on land to create nests dramatically lowers the degree of male-male competition and territoriality. This reduces selection for bigger males; smaller body sizes are particularly important on land where desiccation risk is high and being smaller reduces desiccation. In evolving terrestrial breeding, sexual size dimorphism becomes enhanced as selection for larger males is reduced, allowing males to evolve smaller body sizes while females are still proportionally larger to be able to better produce eggs. They nicely illustrate how natural and sexual selection in conjunction to transitions to different breeding habitats may influence the diversification of amphibian life. (MLambert)
Xenopus laevis by Alexander Haas
November 18, 2019: How does variation in body mass, metabolic rate, and microhabitat use (terrestrial, aquatic, etc.) in frog species impact their ability to inhabit the diverse environments where they are found worldwide? To investigate this, Mokhatla et al. (2019) tested how body mass, body temperature, sex, metabolic rate, and evaporative water loss of three frog species were affected by differences in each other as well as differences in environmental vapor pressure and temperature. They found in all three frog species, as ambient temperature increased, body temperature, evaporative water loss, and whole-animal standard metabolic rate increased as well. However, vapor pressure deficit better predicted rates of evaporative water loss than ambient temperature in the stream-breeding common river frog (Amietia delalandii) and the largely terrestrial raucous toad (Sclerophrys capensis) but not in the principally aquatic African clawed frog (Xenopus laevis). Furthermore, body temperature increased with body mass in A. delalandii and S. capensis but not in X. laevis. Only in the raucous toad did metabolic rate positively correlate with body mass. Interestingly, within species, evaporative water loss was not affected by vapor pressure, body mass, or sex. They showed that within-species variation (such as sex or body mass) may not greatly affect desiccation risk. However, among species, the effects of organismal factors (e.g., body mass) and environmental factors (e.g., vapor pressure, ambient temperature, etc.) on a frog’s physiology may depend on the ecological specialization of the species. In particular, the physiology of aquatic species and the internal and external factors that affect that physiology may differ from more terrestrial species. (MWomack)
Oophaga pumilio by Alberto Sanchez-Vialas
November 11, 2019: Poison dart frogs (Dendrobates pumilio) in the Bocas del Toro region of Panama have island populations which differ in coloration from the mainland, and a new experimental study by Yang et al (2019) shows that imprinting can account for the diversity in coloration on these different islands. Ingenious and demanding experiments demonstrated that female frogs with parents of the same color tended to choose mates of that color and would even do so in the case of foster parents. Similar results were obtained with respect to male-male aggression. Behavior plays a very important role in the lives of these frogs. The new results help understand the spectacular geographic patterns of color diversification in this sinking landscape and its island frogs. (DW)
Anaxyrus californicus by Chris Brown
November 4, 2019: Amphibians are unique among vertebrates for their biphasic life cycle, which uses both aquatic and terrestrial environments. Yet our understanding of tadpole feeding ecology is limited and can have strong implications for species conservation and functional ecology. Montaña et al. (2019) addresses our current knowledge gaps regarding tadpole feeding by revisiting Altig et al.’s 2007 article on the same subject. In Montaña et al.’s review, they found that studies on tadpole feeding are biased towards species in the Americas, specifically towards the families of Ranidae, Bufonidae, and Hylidae, and at small spatial and temporal scales. They urge more studies of African and Asian tadpoles, of more families, and from ecosystem perspectives. They also address the effect of non-native species in tadpole nutrition, competition, and predation. (AChang)
Dendrobates tinctorius by Henk Wallays
October 28, 2019: The evolution of warning signals, such as bright coloration, by chemically defended organisms is of key interest in evolutionary biology. We expect warning signals to be stable and conservative, so would-be predators can rely on these signals to avoid ingesting harmful toxins. Yet in many cases warning coloration is highly variable across species and populations, even within populations. Lawrence et al. (2019) use a variety of tests to investigate color variation between two populations (one with white, and one with yellow stripes) of the dyeing poison frog, Dendrobates tinctorius, known for its extraordinary color pattern variation. Using Plasticene frog models in the field, they show white striped frogs were protected in the range of the yellow frogs, but suffered higher attack rates in their own range, compared to the yellow frogs. The yellow frogs had lower overall levels of toxins, yet were more aversive to bird predators. Hence, white colored individuals would be protected in the range of the (highly aversive) yellow frogs, potentially leading to polymorphism. If individuals with the white stripes colonized a new habitat and became isolated (founder effect), this could lead to the formation of an all-white population. This may be what produced the between-population variation currently observed between the two D. tinctorius populations in this study. Genetic analyses revealed a complete lack of gene flow between the populations, which would shield the white population from invasion by the yellow phenotype. (KSummer)
Ambystoma maculatum by Henk Wallays
October 21, 2019: With over 40% of amphibians threatened with extinction, most conservation actions for amphibians are reactive, which is often costly and prone to challenges that limit the chances of full recovery. Sterrett et al. (2019) outlined a framework for proactively managing amphibian population aimed at ‘keeping common species common’ in ways that minimize costs but maximize the probability of maintaining populations and species. A challenge of developing management plans for common species is that they are considered stable until proven otherwise, usually when an observed or presumed dramatic decline inevitably precipitates reactive management. Their framework for proactive amphibian management before a species is in decline or crisis includes reducing human impacts, implementing harvest quotas, preventing novel threats like contaminants or invasive species, modifying habitat to increase population resilience, and augmenting existing populations. Under this framework, gathering data on species ranges, habitat associations, abiotic requirements and sensitivities, and using data from closely related species can help predict species impact in different future scenarios. They suggest further research on status assessments, developing alternative management plans without necessarily understanding existing threats, and producing predictive models to understand possible future costs of delaying management would help proactively mitigate declines in common species. While their framework components may not be unique, working within these guidelines may help stymie the extinction crisis facing amphibians. (MLambert)
Conraua goliath by Marvin Schäfer and Frogs & Friends e.V.
October 15, 2019: Despite having been described in 1906, little is known about the natural history of the largest frog in the world, Conraua goliath. In their recent paper, Schäfer et al. (2019) shed light on the species' reproductive behavior by documenting their construction of nest sites. The authors described three types of nesting sites they found in West Cameroon that protect developing offspring from river torrents and predators: rock pools, existing washouts, and dug-out depressions in gravel riverbanks. The different types of nest sites have differing levels of construction effort and risk of flooding or drying. However, in each of these sites, the breeding adults cleared the area of detritus and leaf-litter and deposited eggs on multiple occasions. Camera traps showed that adults guarded nests at night, which is consistent with local knowledge. The authors speculate that because large, heavy objects must be moved for nest construction, this type of nest construction may have favored large size in this species. (AChang)
Rhinella marina by Andrés Acosta
October 7, 2019: If you have ever picked up a male cane toad (Rhinella marina) you likely heard it make a noise termed a 'release call'. It is thought these calls send a message to other males- "I'm a male, release me!"– if a male cane toad is grasped by another male to mate. However, Kelehear and Shine (2019) found that about one-third (205 of 625) of male can toads in their study did not emit a release call when clasped. The male cane toads that did not produce a release call were smaller and had poorly developed secondary sexual characteristics, indicating they were likely non-reproductive juveniles. Building on previous work that showed males will release males sooner than females, regardless of a release call, Kelehear and Shine hypothesize that other male-specific cues (such as skin rugosity) provide secondary release cues. Shine and Kelehear further propose that eavesdropping predators, such as nocturnal rodents, may cue in on release calls to find cane toad prey. Thus, for large, reproductively active males, time is of the essence during mating season and release calls ensure much less time is wasted being clasped by another male. However for smaller, less reproductively successful male cane toads, not calling may waste some time but costs very little compared to being a rodent's meal. (MWomack)
Pulchrana grandocula by Joachim Nerz
September 30, 2019: Disease is a key threat to many amphibian populations, therefore, studying how and where diseases are being spread is crucial for amphibian conservation. However, past studies of skin swabs for the devastating amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) only showed where Bd is present or absent, they do not report which specific lineages of Bd are present in each area. This is important because some lineages of Bd are deadlier than others and divergent lineages can hybridize to form new, potentially dangerous lineages. Byrne et al (2019) addressed this gap in knowledge and made important strides in studying this pathogen. By leveraging a new genotyping technique, they were able to use previously collected skin swab samples (including some collected from museum specimens) to describe the global genetic diversity of Bd. Their study discovered a new endemic lineage of Bd in Asia, BdASIA3, and revealed multiple locations around the world where virulent Bd lineages are coming into contact. This large collaborative effort marks progress in understanding this deadly pathogen and indicates that we need to consider doing more to curb the global spread of Bd lineages. View their data on amphibian disease portal here. (AByrne)
Andrias davidianus by Theodore Papenfuss
September 23, 2019: How sex is determined in amphibians is epitomized by diversity. For those species with genetic sex determination, which sex has two types of sex chromosomes (e.g., XY or ZW chromosomes as in mammals and birds, respectively) varies from species to species. To date, most research on the genetics of amphibian sex determination has focused on frogs with little work centered on the salamanders or caecilians. New research by Hime et al (2019) identified a ZZ-ZW female heterogametic sex chromosome system in the salamander family Cryptobranchidae, which includes Cryptobranchus hellbenders from the United States and Andrias giant salamanders from Asia. Using next generation genomic data, the same ZZ-ZW sex-linked regions were discovered in the genomes of both salamander genera. This discovery indicates that the same sex chromosomes have been retained in Cryptobranchid salamanders since the different species diverged roughly 60 million years ago. Their work is particularly impressive given these salamanders’ genomes are enormous at 56 Gb, roughly 18 times the size of the human genome. Beyond the evolutionary implications of understanding a remarkably conserved sex chromosome system in an ancient salamander lineage, they produced a series of sex-linked molecular markers that are sequenced only in genetic females, which will facilitate conservation work on these imperiled amphibians. (MLambert)
Plethodon metcalfi by Bill Peterman
September 16, 2019: Climate change exposes amphibians to a high risk of dehydration in warming habitats, yet we have a very limited understanding of how amphibians might anticipate and prepare for climate change at a physiological level. A recent study by Riddell et al. (2019) discovered that lungless salamanders, specifically Southern Gray-cheeked Salamander (Plethodon metcalfi), use warming temperatures to anticipate the greater risk of dehydration by lowering water loss rates across their skin. Many plants and animals likely use thermal cues to predict their risk of drying out because temperature is correlated with the drying power of the air. Gene expression analyses found that salamanders reduced water loss rates by adjusting blood flow to their skin using pathways associated with regeneration of capillaries in the skin. Their study suggests that regeneration-specific pathways are not isolated to limb regeneration and might play a role in buffering salamanders from climate change. (ERiddell)
Boophis nauticus by Frank Glaw
September 9, 2019: It has long been known that two species of mantellid frogs are widely distributed on the volcanic, oceanic island of Mayotte, in the Comoros Islands northwest of Madagascar. A new study by Glaw et al (2019) using an integrative taxonomic approach has concluded that these species are well differentiated molecularly from all Madagascar species and should be recognized as distinct, Blommersia transmarina and Boophis nauticus. These new species represent two of only five transoceanic dispersals of amphibians in the western Indian Ocean. The species are about 5% diverged in sequences of the mitochondrial gene 16S ribosomal RNA from putative Malagasy relatives. In addition, Blommersia transmarina is the largest member of its genus (which contains 11 species). (DW)
Noblella losamigos by Alessandro Catenazzi
September 2, 2019: With global warming underway, it is unclear if amphibians of the lowland tropics will be able to cope. A recent study by von May et al (2019) reports critical thermal limits of 56 species of sympatric lowland Amazonian frogs in Peru. Small, directly developing strabomantids, such as newly described Noblella losamigos (Santa-Cruz et al 2019), appear to be at the highest risk of thermal stress whereas hylid and microhylid frogs more effectively tolerate higher temperatures. In von May and colleagues' work, they estimate that 4% of lowland rainforest frogs studied will experience temperatures exceeding their thermal tolerances, and fully 25% might be moderately affected under a hypothetical 3°C increase in environmental temperature. (DW)
Centrolene savagei by Victor Fabio Luna-Mora
August 26, 2019: Parental care has the tradeoff of high offspring survival at great cost of time and/or energy to the care giving parent. Amongst terrestrial vertebrates, amphibians are remarkable for their diversity of parental care. While 80-90% of amphibians provide no parental care, some species are known for creating nests for eggs, guarding eggs, incubating eggs internally, transporting larvae, and/or providing nourishment to larvae. Additionally, because terrestrial environments are hostile for amphibian eggs, parental care may be necessary for offspring survival in terrestrial environments. Vági et al. (2019) examined the relationship between the evolutionary origins of anuran parental care and terrestrially via a comprehensive phylogenetic analysis. Their findings indicate that the duration of parental care and offspring protection co-evolved with terrestrial reproduction and independently arose multiple times. Species exhibiting parental care also had less sexual size dimorphism suggesting that male parental care may reduce the selection pressure on female fecundity or parental care in general increases the tradeoff of high offspring number to offspring survival. Although further investigations are needed, these findings show that parental care is predictable based on ecological and life history traits in frogs and this ability may have implications for managing species with regards to climate change and captive husbandry. (AChang)
Anaxyrus terrestris by Frank Teigler
August 19, 2019: Wetland contamination threatens many amphibian species that rely on the aquatic habitats for survival and larval development. Heavy metal contamination can be lethal to wildlife and can result from waste run-off. However, Flynn et al. (2019) recently found some cause for hope that Southern toads (Anaxyrus terrestris) may be able to combat copper contamination to some degree. Tadpoles from wetlands that have elevated copper levels were more likely to survive copper exposure in the lab than tadpoles from wetlands with lower copper levels. Given the elevated copper in these wetlands likely resulted from human influences over the past 20 years, it appears these toad populations have responded to a stressor relatively quickly. They provide some evidence and hope for amphibian resilience in the face of heavy metal contamination. However, further studies are needed to understand long-term effects of heavy metals on survival and fitness beyond the tadpole stage. (MWomack)
Rana pipiens by Louis-M. Landry
August 12, 2019: Understanding the ways climate change may impact species survival is critical for conservation planning. Many amphibian species rely on ephemeral or semi-permanent water bodies for the egg and tadpole stage of their lifecycle. But what happens to amphibians when these ponds dry up faster than ever before? A group of researchers led by Laura Brannelly and Michel Ohmer (2019) recently published a study testing this question using the Northern Leopard Frog (Rana pipiens) grown in controlled, outdoor pools called mesocosms. They found that metamorphosed individuals reared in pools that dried faster were significantly smaller and had a reduced immune response, indicating a multidimensional negative impact of faster pond drying. It will be important to factor these findings into future predictions and planning for amphibians that rely on these vulnerable ephemeral habitats. (AByrne)
Hyla cinerea by Michael Spencer
August 5, 2019: The permeable skin of amphibians makes them particularly vulnerable to chemicals in their environments, including salt, which can slow down development or even cause death at high enough levels. However, a few amphibians lay their eggs in brackish water, begging the question of how these critters survive salt exposure. In a recent study, Albecker and McCoy (2019) found that coastal populations of Hyla cinerea, the American Green Treefrog, survive better and grow faster in salty environments than their inland counterparts. The authors suggest that Green Treefrogs have evolved to tolerate high salt levels in part by shortening their larval period and reducing the length of time the tadpoles are exposed to high salt levels. Future studies may reveal how these coastal frogs process higher levels of salt with specialized physiology. (RTarvin)
Leptodactylus savagei by Thomas Eltz
July 29, 2019: Many frog and toad species produce loud vocalizations to communicate to other members of their species, often to defend territories or attract mates. Many predators, like bats, or parasites, like blood-sucking midges, also use these calls to find and attack their amphibian prey. Midges may be particularly troublesome for frogs because they can cause irritation, blood loss, and increase pathogenic infections. Virgo et al (2019) experimentally tested how characteristics of the calls of different species in a Costa Rican frog community influence how often midges attack various frogs. Frogs that call at low frequencies (<1 kHz) and with a shorter pulse (250-500 ms) attracted the most midge attacks. In particular, frog-biting midges prefer frog calls that were not continuous but which pulsed with very short inter-pulse durations. This is fascinating because it suggests midges are able to detect complex, trilling calls as are common of many toad species that can easily blend in with ambient background noise. Interestingly, frog species differ in how often they are bitten by midges and different midge species prefer different types of frogs. Calls of the giant bullfrog (Leptodactylus savagei) attract the most biting midges and some midges prefer frog species of the genus Leptodactylus while others prefer hylid tree frogs. This new work highlights that the incredible diversity of frog calls in a given community shapes the evolution and preferences of different blood-sucking midge species which can subsequently influence the health of parasitized frogs. (MLambert)
Hyperolius riggenbachi hieroglyphicus pair by Daniel Portik
July 22, 2019: Despite the theory that sexually dimorphic traits under strong sexual selection lead to rapid diversification, phylogenetic studies testing for correlations between sexual dichromatism (sexual differences based on coloration and pattern) and diversification have had mixed results. Although sexual dichromatism is rare in most frogs, it is common in the species-rich African reed frogs (Family Hyperoliidae) with females being more strikingly ornate than males. Portik et al. (2019) examined the group to better understand the evolutionary origins of sexual dichromatism and how it relates to their diversification. Sexual dichromatism evolved once followed by multiple reversals to monochromatism. Clades displaying dichromatism had about double the rates of diversification of monochromatic clades. African reed frogs are a promising group for exploring the role of natural and sexual selection on the evolution of sexual dichromatism. (AChang)
Ameerega trivittata by Eric Vanderduys
July 15, 2019: The larvae-toting parental care of many species of the Family Dendrobatidae is known to be an effective way to ensure tadpoles have food and protection while they develop. A study by Pašukonis, Loretto and Rojas (2019) asked further about the role of this parental shuttling in dispersal. With tiny radio transmitters, they tracked two poison frog species (Ameerega trivittata and Dendrobates tinctorius) and found that they moved their offsprings farther and to many more water sources than expected, with little regard to suitable, nearby pools. Examining the spatial patterns of the far-ranging fathers, the authors speculate on the adaptive benefits of ensuring the dispersal of their offspring to reduce competition and possible inbreeding against the increased costs and risks associated with long-distance travel. Their study highlights the parental role in offspring dispersal and the spatial acuity of these poison frogs. (MK)
Andrias davidianus by Axel Hernandez
July 8, 2019: Amphibians have a long history of medical use with many innovations still to be discovered. Building off of traditional uses, Deng et al. (2019) explored the use of skin secretions from Andrias davidianus (SSAD), which can be humanely collected twice a month, as a medical adhesive. Current methods of wound closure include mechanical closures (e.g., staples and sutures) and adhesive closure materials (e.g., synthetic polymers and naturally derived fibrin glue from mussels). Using freeze-dried then rehydrated SSAD, Deng et al. compared the effectiveness of these different wound closure materials in ex vivo and in vivo (in rats) experiments. They found that SSAD adhered tissue equal to or better than other adhesive materials and was more flexible. Additionally, SSADs had the best wound healing times with regenerative properties and minimal scarring than all of the other methods. SSAD also degenerated quickly in live tissue with a minimal immune response. Testing is still needed to determine how SSADs will interact with human tissues, but these results have exciting implications for post surgery recovery. (AChang)
Hyla chrysoscelis by Todd Pierson
July 1, 2019: Aquatic amphibian larvae concentrate nutrients from rich aquatic environments and, after metamorphosis, dispense these nutrients through the landscape, subsiding nutrient-poor terrestrial ecosystems. Massive amounts of amphibian biomass, sometimes over 1,400 kg (Gibbons et al 2006), leave wetlands and enrich terrestrial ecosystems. A recent study by Fritz et al (2019) found that amphibians may play a more important role in subsidizing nutrients into depauperate terrestrial landscapes than we previously understood. They traced one type of organic molecule, long-chain polyunsaturated fatty acids (LC-PUFAs), which are critical for keeping animals healthy, but many animals cannot produce LC-PUFA’s in sufficient quantities. LC-PUFAs, however, are readily made by algae and are subsequently concentrated in higher levels of aquatic food chains as various organisms consume algae or consume other animals that have eaten algae. Thus, aquatic ecosystems are richer in important LC-PUFAs than terrestrial ones. They measured LC-PUFAs in eight amphibian species (3 salamanders, 5 frogs) as larvae metamorphosed out of eight temporary wetlands and found ~230,000 larvae metamorphosed in a single year bringing vast amounts of critical LC-PUFA to terrestrial consumers. Each species varied in LC-PUFA concentrations but, interestingly, although larval salamanders are higher in the food chain and therefore were expected to concentrate more LC-PUFAs, frog tadpoles were comprised of higher amounts of LC-PUFAs. While it’s well understood that emerging aquatic insects provide substantial subsidies to terrestrial ecosystems, this work shows amphibian metamorphs may be as important or an even greater source of LC-PUFAs from rich aquatic habitats onto land. These findings document a critical role amphibian diversity plays in maintaining not only aquatic but also terrestrial ecosystem health and highlights the importance of protecting these species and their fragile habitats. (MLambert)
Salamandra salamandra terrestris by Paul Bachhausen
June 24, 2019: Although Fire Salamanders are assumed to be an aposematic species, where bright colors are viewed by potential predators as warning of toxicity, the costs associated with the honesty of their signaling and predator learning behavior has not been quantified. Preißler et al. (2019) tested whether the alkaloid content matched yellow coloration in a highly variable Fire Salamander population in Solling, Germany, (Salamandra salamandra terrestris) to determine if the species had an honest signal of toxicity. They found that the amount of yellow patterning did not correlate with the amount of toxins in individuals, as would be expected for a true aposematic species. The authors also found that the population was sexually dichromatic, with males being more yellow than females. Although these findings could be explained by sexual selection, statistical analysis of color variation indicated that site specific female choice was not a factor. These findings indicate that other, yet to be verified, biological processes are playing a role in the yellow coloration of Fire Salamanders, and that the toxins are produced by conserved bioactivity. (AChang)
Xenopus laevis by Ronn Altig
June 17, 2019: Amphibians are unique among tetrapods in their ability to regenerate their appendages, like arms or tails, when removed. The particular mechanisms underlying appendage regeneration, however, are poorly known. A recent study (Aztekin et al 2019) combined tail amputation experiments in tadpoles of the African clawed frog (Xenopus laevis) with single-cell RNA sequencing, allowing researchers to study how different genes work in individual cells of various cell types during tail regeneration. This study discovered a previously unknown cell type named the regeneration-organizing cell (ROC). Removing ROCs from severed tails demonstrated that ROCs are necessary for tadpoles to regrow their tails. Transplanting these cells to other areas of the embryo demonstrated these cells are sufficient to grow tail-like structures elsewhere in tadpoles. ROCs are normally found in the epidermis and migrate to the wound site after tadpole tails are amputated, secreting similar regenerative compounds that are produced when salamanders regrow limbs. The discovery of a new cell type that enables amphibian larvae to regrow appendages has exciting implications for tissue and organ transplant procedures and is an important reminder that we have much yet to learn about the amazing biology of amphibians. (MLambert)
Caecilia thompsoni by Esteban Alzate
June 10, 2019: Caecilians form a unique group of amphibians that is largely fossorial, contains 212 species, and diverged from the rest of amphibians approximately 250 million years ago. Bardua et al. (2019) examined how the caecilian skull had evolved over time and in relation to evolutionary transitions in ecology, diet, and development. They studied skull evolution among all 32 extant caecilian genera using an impressive dataset that included over 1000 landmarks and semi-landmarks on the skull. They found that 10 regions (modules) of the caecilian skull have evolved somewhat independently of one another. This was surprising given mammals and birds, which are more specious and diverse in ecology, have shown fewer regions of independent skull evolution. Furthermore, this study found changes in skull evolutionary rate associated with evolutionary transitions to fully aquatic lifestyles, direct development, and viviparity. Interestingly, the fastest-evolving skull structures are related to the unique dual jaw-closing mechanism caecilians use to feed, providing evidence that these structures were likely a prime target of selection. (MWomack)
Dendrobates auratus by Frank Steinmann
June 3, 2019: Amphibian genomes can be extraordinarily large, making it difficult to connect the genotype to the phenotype using large-scale genome-sequencing methods. One approach to this challenge is to take a transcriptomic approach, focusing on differential gene expression across different phenotypes in specific tissues. Stuckert et al. (2019) take this approach to investigate differential gene expression across distinct color pattern morphs in the green and black poison frog (Dendrobates auratus). These morphs vary in both background color (brown to black) and foreground (green to blue). They sequenced transcripts from skin tissue taken from tadpoles just reaching metamorphosis, an active period for pigment deposition and skin color development. A number of candidate color pattern genes were found to be differentially expressed between morphs, including genes involved in melanin production and melanosome development in basal skin layers (e.g. the tyrosinase-related protein 1, which catalyzes several key steps in melanogenesis, and affects dark coloration in a variety of vertebrates), genes involved in the development of iridophores (middle layer organelles containing reflective structures associated with blue-green coloration), and genes involved in yellow, orange and red pigment production in xanthophores (e.g. genes in pteridine pigment production pathways). These results will begin to provide insights into the genetic underpinnings of color variation in the brightly colored Neotropical poison frogs. (KSummers)
Atelopus zeteki by Edgardo J. Griffith
May 27, 2019: The current climate crisis has had far-reaching effects on our environment, but how has climate change impacted amphibians and their vulnerability to disease? A study by Cohen et al. (2019) combined lab experiments and observations of decline patterns to evaluate the impact of climate change on disease vulnerability in the imperiled harlequin toads (genus Atelopus). Their study, published in Global Change Biology, used infection experiments to show that one species – Atelopus zeteki– was most vulnerable to Batrachochytrium dendrobatidis (Bd) at high temperatures (28°C). This was unexpected given Bd had an optimal growth rate at a much lower temperature (18°C) in culture. Furthermore, they built models to evaluate patterns of decline for 56 Atelopus species that may have been impacted by Bd. They found that Atelopus from cooler environments had higher extinction risk from climate change than those from warmer environments. These results challenge a common assumption that Bd outbreaks may only occur at cool/moderate temperatures and identify cool-adapted, range-restricted species as being the most vulnerable to synergies between climate change and disease. (AByrne)
Nectophrynoides asperginis (Extinct in the Wild) by John P. Clare
May 20, 2019: A newly issued report from the United Nations Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) contains much sobering information. The extinction rates for species are accelerating (although only a few amphibians have gone extinct as yet, more than 40% are at some risk of extinction). We have long known that current climate change is seriously impacting natural populations and ecosystems but the global response is wholly insufficient. The report, the most comprehensive assessment ever attempted, finds that a million species are threatened with extinction. It is not too late to make a difference, but only if we start transformational change immediately. But opposition is to be expected from those with entrenched interests. The global safety net has been stretched nearly beyond recovery. The reasons for the crises are the direct result of human activity. The main culprits, in order of importance are: 1) changes in land and sea use; 2) direct exploitation of organisms; 3) climate change; 4) pollution and 5) invasive alien species. As never before the need is for individuals to think globally but act locally. This impressive report has caught the attention of leaders in Washington, DC, and should serve as a rallying cry and guide to future action. (DW)
Rana draytonii by Zachary A. Cava
May 13, 2019: The California Red-legged Frog, Rana draytonii, has not been seen in Yosemite National Park for at least 50 years. Yet, thanks to the cooperative efforts of the National Park Service, Yosemite Conservancy, San Francisco Zoo & Gardens, U. S. Fish & Wildlife Service, California Department of Fish & Wildlife, and NatureBridge, once again Red-legged frogs are back in Yosemite. In a program that began in 2016, an estimated 4,000 frog eggs and 500 adult frogs have been reintroduced from a captive breeding program at the zoo. But with another 200 adult frogs released in April and another 275 to be released in June, the reintroduction program is now fully operational. The captive population was founded with frogs collected in El Dorado County, in the foothills of the Sierra Nevada north of Yosemite. The frogs were released in Cook’s Meadow, in view of Yosemite Falls in Yosemite Valley. Transponders attached to 75 frogs will enable researchers to follow the frogs in the future. This trial reestablishment might set the stage for future attempts in other parts of the Sierra Nevada where the frogs once thrived. (DW)
Pleurodema diplolister by Mauro Teixeira Jr.
May 6, 2019: Amphibians are able to survive for long periods under conditions of severe environmental dryness. Frogs occupying the semi-arid Caatinga region of Brazil -- about 18% of Brazilian territory and experiences a three-month dry season that may become extended by months or even years-- were investigated to determine if any special features exist that enable them to survive such conditions. The frogs form concentrations in beds of temporary rivers, where they survive for long periods. No morphological features of special survival value were found, but a combination of lethargy during aestivation and a highly permeable integument which enable frogs to detect decreases in moisture levels and move to more favorable settings facilitates their survival. When rain finally falls, explosive breeding is typical of many of the species. Behavioral adjustments are the keys to survival. (DW)
Philautus ingeri by Maximilian Dehling
April 29, 2019: Robert F. Inger of the Field Museum, Chicago, Illinois, died April 12 at the age of 98. He was the curator of amphibians and reptiles at the Field Museum of Natural History for 40 years and continued to be active in research until recently. Inger’s doctoral research at the University of Chicago on the zoogeography and systematics of Philippine amphibians set the direction of his research in southeast Asia, which he continued throughout the rest of his life. He conducted field work on Borneo, especially in Sarawak, for over 50 years. In addition, he conducted field work in central Africa, in India and other areas. Thoughout his long career, his major focus was Amphibia, describing over 200 new species, but he published extensively on squamates and freshwater fishes as well. He was actively involved in the Declining Amphibian Population Task Force and leaves a deep imprint on our knowledge of the biology of amphibians through his integrated research on the systematics, ecology, and conservation of amphibians in southeast Asia. (DW)
Brachycephalus ephippium by Sandra Goutte
April 22, 2019: Fluorescence is a well known phenomenon in marine organisms, which only recently has been found in terrestrial vertebrates; the first report of fluorescence in amphibians was described in the lymph and skin glands in Boana punctatus and B. atlantica (Taboada et al. 2017). Goutte et al. (2019) reports another amphibian fluorescence: this time in the dermal bones of two species of pumpkin toadlets, Brachycephalus ephippium and B. pitanga. When exposed to intense UV-light, they found the intensity of fluorescence increases with the maturity of the frog as the epithelial layer co-ossifies with the bones of the head and back. Given earlier findings (Goutte et al. 2017) that these two species were unable to hear their own advertisement calls, and instead rely on visual cues, such as hand-waving and mouth-gaping for mating, they hypothesize that the fluorescence in these species may be used to enhance intraspecific visual communication. However, analysis of Brachycephalus vision is needed to test this hypothesis, and an alternative hypothesis is that the fluorescence enhances aposematic warnings of the toadlets' toxicity to predators that see fluorescence in natural light, such as birds and spiders. (AChang)
Photo by Michael Lannoo; artwork by Tim Halliday
April 15, 2019: Amphibian biology has lost one of its most distinguished and influential spokesman: Tim Halliday died on April 10, 2019 following a long illness. Tim was the long-time International Director of the Task Force on Declining Amphibian populations. He was well-known for his extensive work on the breeding behavior of newts and his professional career was as a professor at The Open University. He was an accomplished artist who drew and painted amphibians and birds with vibrant realism. Among his numerous publications are his recent wonderful contribution, The Book of Frogs (Ivy Press, 2016). Tim contributed the monthly recent literature section to AmphibiaWeb for many years. Tim Halliday was dedicated to the conservation of wildlife in general, and his many accomplishments and service are an inspiring legacy. He will be sorely missed. (DW)
Eleutherodactylus bartonsmithi by Ariel Rodriguez
April 8, 2019: Adaptive radiations are commonly reported in island systems, where species initially colonize the islands and then diversify to fill somewhat consistent ecological roles on each island. Recently Dugo-Cota et al. (2019) studied 160 species of frogs (genus Eleutherodactylus), which are found throughout the Caribbean islands. They found different species inhabited different parts of their environment (termed microhabitats - Arboreal, Bromelicolous, Cave-dwelling, Fossorial, Leaf-litter, Petricolous, Riparian, Semiarboreal, Stream-dwelling, and Terrestrial). Furthermore, they found that species independently diversified into these different microhabitats on almost every island, with the exception of fossorial species, which are only found on Hispaniola. The frog species that occupied the same microhabitats looked significantly similar (morphological convergence), except for stream-dwelling and riparian species, which had very few representative species. These results show Eleutherodactylus frogs have adaptively radiated throughout the Caribbean and support the idea that evolution can and does repeat itself under similar environmental and ecological conditions. (MWomack)
Telmatobius hintoni by Arturo Munoz
April 1, 2019: A new study by Scheele et al. (2019), prominently published in the magazine Science, reviews the impact of the amphibian chytridiomycosis panzootic, finding that it is ongoing and continuing to have profound impact on amphibians around the world. Having a "catastrophic" impact, it is the leading cause of decline of more than 500 species and the extinction of as many as 90 species of amphibians. While some species have shown signs of recovery, most that were affected by chytridiomycosis continue to be negatively impacted. The study focuses attention on the worldwide nature of the panzootic and its effect on much of the amphibian tree of life. The authors contend that chytridiomycosis has led to the greatest recorded loss of biodiversity that can be attributed to a single disease. (DW)
Rana catesbeiana by Patrick D. Moldowan
March 25, 2019: Researchers are increasingly interested in understanding the microbes (e.g., bacteria) living on amphibian skin. Largely because microbes, and the chemicals they produce, might help amphibians fight off infectious disease like the amphibian chytrid fungi Batrachochytrium dendrobatidis and B. salamandrivorans. How the microbial community living on amphibian skin is shaped by global differences in environmental conditions or amphibian species identity (i.e., due to phylogenetic relationships) has remained predominantly unexplored. Recently, Kueneman et al. (2019)compiled microbial species richness and community data from amphibian skin swabs sampled by researchers across the globe. Their analyses found that microbial species richness (the total number of species) was highest in parts of the world with the coldest winter months and in environments that were more seasonal. They observed this same pattern in American bullfrogs, a globally invasive species, collected from populations in the USA, Japan, South Korea, and Brazil. Interestingly, which family an amphibian species belongs to has minimal influence on the microbial community living on it and there are no consistent relationships between what type of habitat a species lives in (e.g., aquatic or terrestrial) and its skin microbes. This study highlights how global environmental conditions, and perhaps climate change, might influence the diversity and composition of microbes living on amphibians and how amphibians are able to cope with infectious disease in different parts of the world. (MLambert)
Ranitomeya imitator by John P. Clare
March 18, 2019: Monogamy in vertebrate evolution appears multiple times in separate lineages but their underlying genetic underpinnings are only recently explored. Young et al. (2019) compared differential gene expression between the transcriptomes of monogamous and polygamous species in five sets of species pairs across vertebrates (mice, voles, birds, frogs and fish). The frog pair were poison frogs Ranitomeya imitator (monogamous) and Oophaga pumilio (polygamous). Tests for differential gene expression between each pair revealed that congruent sets of genes (orthologous or genes of the same evolutionary genealogy) showed concordant changes in expression between the monogamous and the polygamous lineages. The directions of changes in expression in these gene sets were also concordant, such that genes which decreased in expression in the monogamous lineage of one taxonomic pair were likely to decrease in expression in the other monogamous lineages as well (for all pairwise comparisons). However, the frog species were unique in that some genes displayed the opposite direction of change in expression relative to other monogamous lineages. The poison frogs are the only lineage here in which male parental care is ancestral so monogamy with biparental care in this lineage evolved from male care (rather than female care, as in the other taxa). Overall, their research yielded a novel set of 24 candidate genes likely to be involved in the evolution of monogamy, many of which are involved in neural development, synaptic activity and cognitive function. The study provides evidence for widely conserved sets of shared genes and molecular genetic pathways contributing to the evolution of monogamous mating systems across vast gulfs of evolutionary time and change in the vertebrate lineage. (KSummers)
Rhinella jimi by Mauro Teixeira Jr.
March 11, 2019: While vehicular collisions on roads are known to kill numerous wildlife each year, railroads have received substantially less attention, particularly with respect to amphibians. Dornas et al (2019) examined toad fatalities across an 871-km railroad segment in the Brazilian Amazon, one of the last few large wildlife refuges with minimal landscape development. The researchers recorded 9,091 Cururu toad (Rhinella jimi, R. marina, and R. schneideri) carcasses along the railroad, an average of 2,273 toad killed by the railroad per year, over a four-year period. Interestingly, not all toad carcasses showed signs of being hit by moving trains. Many toads died by barotrauma, where sudden changes in air pressure due to rapidly moving train violently pushes air against toads, everting their stomachs out of their mouths and killing them. Small toads were also desiccated because they were too small to climb and move across the railroad tracks to find moist shelter. In general, toads are most vulnerable to railroads during the transition between the dry and wet seasons as they migrate. By experimentally manipulating carcasses, the researchers showed that this railroad likely causes over 10,200 toad fatalities per year with 8-12 toads kill per km of railroad each year. This study highlights railroads as a particularly lethal threat to amphibians, even in relatively undeveloped landscapes. (MLambert)
Boana prasina by Mauro Teixeira Jr.
March 4, 2019: Amphibians possess diverse skin secretions and microbiota, yet we know little about how these chemicals or bacteria are used to communicate. By comparing volatile (odorous) chemicals from Boana prasina treefrogs and from bacteria grown from their skin, Brunetti et al (2019) discovered that the strong odor of B. prasina is partially produced by skin-living bacteria. Odor-producing bacteria had been identified in mammals and insects but were previously unknown in amphibians. Brunetti and colleagues also found that odorous (volatile) chemical profiles differed substantially between males and females, perhaps because of differences in how they spend their time or what they eat, which can influence what microbes survive on the frogs. However, Brunetti et al also suggest that these chemical profiles may be shaped by natural selection and could play a role in communication, but that more research is needed to test this hypothesis. As stated in their article, "studies on the ecological role of host–microbiome associations in amphibians are in their early infancy" – and we look forward to hearing more. (RTarvin)
Desmognathus fuscus by Todd Pierson
February 25, 2019: Most salamanders must breath in both water and air so they use gills, lungs, skin, and other organs for breathing at various times during development. Plethodontid salamanders, also known as lungless salamanders, do not even have lungs and rely heavily on breathing through their skin and an area near the back of their mouth. Until recently, the molecular changes that allow lungless salamanders to efficiently breath through their skin have remained completely unknown. Lewis et al. (2018) show that lungless salamanders express a novel paralogue of the gene surfactant-associated protein C (SFTPC) within areas (such as the skin) that lungless salamanders use to breathe. In other vertebrates, SFTPC is critical for gas exchange in the lungs and is expressed only in the lungs. This new paralogous gene appears to be found only in salamanders, but, similar to SFTPC, in lunged salamanders it is expressed only in the lung. Lewis et al. (2018) propose that this new gene paralogue may be one reason lungless salamanders have thrived and account for more than two-thirds of salamander species. (MWomack)
Eurycea latitans by Tom Devitt
February 18, 2019: The Edwards-Trinity aquifer system of west-central Texas is one of the richest groundwater ecosystems on earth, home to dozens of endemic species with narrow distributions. In a detailed study, Devitt et al (2019) investigated the phylogeography of groundwater-obligate endemics, which is comprised of 15 species of permanently aquatic plethodontid salamanders (genus Eurycea). They inhabit surface springs and spring-fed streams, and water-filled caves and conduits below ground. Some live temporarily in the aquifer, while others are obligately subterranean, appearing on the surface only accidentally. Diversification has been driven by dynamic geomorphological and hydrogeological processes, resulting in instances of both adaptive and nonadaptive population divergence and speciation. The narrow ranges and high degree of specialization of these salamanders make them especially vulnerable to changes in water quality and quantity resulting from rapid urbanization and climate change. As a result, several species have been listed as threatened or endangered under the U.S. Endangered Species Act and are highly vulnerable to extinction. This study brings value to the conservation of this understudied, difficult to access but critical biological resource (Tracy 2019). (TDevitt)
Rana sierrae by Sam Murray
February 11, 2019: A study by Ellison et al (2019) investigates the interaction between Batrachochytrium dendrobatidis (Bd), the pathogen that causes the disease chytridiomycosis, and the bacterial skin microbiome of the endangered Sierra Nevada Yellow‐legged frog, Rana sierrae, using both culture‐dependent and culture‐independent methods. The study found that the skin microbiome of highly infected juvenile frogs is characterized by significantly reduced species richness and evenness, and by strikingly lower variation between individuals, compared to juveniles and adults with lower infection levels. In a culture‐dependent Bd inhibition assay, the bacterial metabolites we evaluated all inhibited the growth of Bd. Together, these results illustrate the disruptive effects of Bd infection on host skin microbial community structure and dynamics, and suggest possible avenues for the development of anti‐Bd probiotic treatments. (VV)
Cryptobranchus alleganiensis by Twan Leenders
February 4, 2019: Eastern hellbenders (Cryptobranchus alleganiensis alleganiensis) are entirely aquatic, giant salamanders, which inhabit fast-flowing streams in North America that have clean water and rocky bottoms. Eastern hellbender populations have been experiencing tremendous declines and are currently being considered for listing under the U.S. Endangered Species Act. Wineland et al. (2018) evaluated eastern hellbender population persistence in West Virginia, a poorly studied portion of the species’ range. Using environmental DNA (eDNA), they found that over a third of sites in West Virginia that historically harbored hellbenders no longer do. Of the locations where hellbenders remained, many were in or near the Monongahela National Forest. Statistical models by Wineland and colleagues further suggested a higher density of roads surrounding historical populations may have led to population declines and extirpations. This is likely because roads and other impervious surfaces release substantial runoff that degrades water quality and alters stream flows. This work using eDNA highlights the importance of minimizing future landscape development while also protecting existing forests and reforesting degraded terrestrial landscapes to protect highly sensitive freshwater amphibians like imperiled hellbenders. (MLambert)
Limnonectes palavanensis by Johana Goyes Vallejos
January 28, 2019: Sex role reversal, in which the time, effort and risk invested in offspring by male parents exceeds that of females, is a rare phenomenon with important implications for sexual selection theory. Under sex role reversal, males invest so much time and effort into caring for offspring that they become a limiting resource for females, and females actively compete for access to potential mates. Previous research has identified sex role reversal in a few birds (e.g. jacanas) and insects (e.g. Australian kaytidids in the family Tettigoniidae). In amphibians, evidence has been sparse. In the Majorcan midwife toad, males care for clutches of eggs wrapped around their legs, and there is some evidence that females actively court and compete for males. New research provides evidence that sex role reversal may occur in Palawan Wart Frog from Borneo, Limnonectes palavensis. Goyes Vallejos et al. (2017) found that female Limnonectes palavensis called more frequently than males, and that multiple females would approach individual males and call to them. Subsequently Goyes Vallejos et al. (2018) demonstrate that males spend long periods of time caring for their offspring. They do not attempt to leave the area or search for new mates while caring for a clutch. While further evidence is needed to conclusively demonstrate sex role reversal, this species provides one of the best candidates for this phenomenon in frogs to date. (KSummers)
Dr Lee Berger
January 21, 2019: For her breakthrough research on chytridiomycosis, a disease that affects amphibians and is likely the worst amphibian disease in history, Dr. Lee Berger was awarded Australia’s Prime Minister’s Prize for Science in Fall 2018. A decade ago, Dr. Berger and an interdisciplinary team of scientists discovered the pathogenic chytrid fungus, Batrachochytrium dendrobatidis, as the cause of mass die-offs of amphibians. The discovery was almost 20 years after global amphibian declines began. Part of the reason it may have taken scientists so long to discover the disease is because the idea that an infectious disease might be responsible for host extinction events seemed unlikely given that disease theory suggests hosts would be expected to evolve resistance or that a disease caused by a hyper-virulent pathogen may fade out when hosts disappear. Dr. Berger’s research not only changed our understanding of the foundations of disease ecology, but also has helped motivate research to discover pathways to mitigate the effects of the disease. She continues her active research on fungal pathogens. (VV)
Rana sylvatica by Tracy Langkilde
January 14, 2019: Human activities ranging from vehicle traffic to industry are making the world an increasingly noisy place to live in; two recent studies show frogs have found ways to cope with the human soundscape. Tennessen et al. (2018) studied wood frogs (Rana sylvatica) in northeastern United States where noise from vehicle traffic is physiologically stressful to recently metamorphosed tadpoles, negatively impacting frog health. However, these researchers found that wood frogs from populations living near human noise have rapidly evolved to no longer be stressed by noisy human environments. In Panama, predators like bats and midges avoid noisy urban areas because they rely on sounds to hunt. Halfwerk and colleagues (2018) found that male túngara frogs (Engystomops pustulosus) from urban habitats can flexibly adjust their calls. Urban dwelling male túngara create more conspicuous calls, which are more attractive to females. When these urban males are placed in the forest, they adjust their calls to be less conspicuous and therefore less obvious to predators. Male túngara frogs from forests are unable to flexibly adjust their calls if they are placed in the city. Together, these studies show that some frogs species can rapidly evolve to deal with noisy human environments whereas others can adjust their behaviors accordingly. (MLambert)
Glandirana rugosa by Pierre Fidenci
January 7, 2019: How sex is determined in frogs is complicated. In some species, males have two different sex chromosomes (an XX-XY sex chromosome system, like mammals) whereas females of other species are the sex with two different sex chromosomes (a ZZ-ZW sex chromosome system, like birds). Whether a species has an XX-XY or ZZ-ZW system has changed dozens of times throughout frog evolution. The Japanese wrinkled frog (Glandirana rugosa) is an evolutionary witness to the remarkable complexity of frog sex determination. Some populations have an XX-XY sex chromosome system whereas others have a ZZ-ZW system. In central Japan, there are adjacent populations of wrinkled frogs with different sex chromosome systems. Ogata et al. (2018) recently discovered a hybrid zone where these two populations meet. They found here a ZZ-ZW system but also a hybrid sex chromosome system. In this hybrid population, the Z-chromosome is partially derived from the old ZZ-ZW population’s Z-chromosome and partially derived from the XX-XY population’s Y-chromosome. The hybrid population’s W-chromosome is surprisingly derived from the X-chromosome of the XX-XY population. This work illustrates how the fantastic diversity of sex determining systems in frogs can arise from recycling sex-determining genomic material across populations and species. (MLambert)


back to News by Year
Bolitoglossa dunni by Franklin Castaneda
December 31, 2018: Happy New Year's from AmphibiaWeb! 2018 has been a productive year: we've added 155 new species, mapped over 300 species ranges, and added 62 species accounts from four herpetology classes. We've also revamped all our family pages. The Amphibian Disease portal continues to grow hosting now almost 18,000 samples from 353 species and 25 countries. We also authored a few friendly papers on amphibians: Amphibian Primer in Current Biology is a concise introduction to amphibians and the Science Journal adapted a recent paper on Bullfrogs and Bd in a primer aimed for teenagers. What may be most noticeable is our new logo on the website! Talented, SF Bay Area animator Jonathan Monterroso created our recognizable new logo which has now launched new items for sale on our Zazzle store. Best wishes to you in the new year and please look forward to many new things at AmphibiaWeb!
Lithobates michiganus by unknown
December 24, 2018: The Onion recently announced the discovery of a new species of ranid frog from Michigan, Lithobates michiganus. The species is diagnosed from others by the possession of a hat and cane and baritone singing voice, among other characters. While a scientific name, diagnosis, and photograph are provided in the electronic publication, AmphibiaWeb has not added this new species name to our database because the information provided does not meet the requirements for availability as set out by the International Code of Zoological Nomenclature. While the Code can sometimes be confusing, AmphibiaWeb has recently posted guidelines for making new taxonomic names available in electronic publications, and the Taxonomic Subcommittee has forwarded a copy to the editorial staff of The Onion. (DB)
Anaxyrus terrestris by William Flaxington
December 17, 2018: One outstanding debate in the chytrid literature is whether amphibians use behavioral thermoregulation to fight off infection. A recent study by Sauer et al. (2018) put this question to the test using five different amphibian species infected with Bd and exposed to a thermal gradient. They found no evidence of behavioral thermoregulation in any species but did find a correlation between thermal preference and Bd growth. They found that species adapted to cold temperatures had higher Bd growth at warm body temperatures, and species adapted to warmer temperatures – such as the Southern Toad (Anaxyrus terrestris) – had lower Bd growth at higher body temperatures. The authors argue that previous studies finding associations between host temperatures and Bd abundance were a result of the pre-existing variation in thermal preference between individuals rather than a behavioral response to being infected. This study advances our understanding of how selection may act on individuals within a species to confer Bd resistance. (AByrne)
Mercurana myristicapalustris by Ansil B. R.
December 10, 2018: Described in 2013, Mercurana myristicapalustris is a rare frog species that has a limited range, inhabiting the once-widespread evergreen Myristica swamp forests of the Western Ghats of India. Abraham et al. (2018) report an extensive investigation into the reproductive behavior and larval development. Reproducing during the short pre-monsoon season, this frog displays a mixture of prolonged and explosive breeding, with males using acoustic and physical defenses of calling perches while advertising to females with a complex repertoire. Once in axillary amplexus, the larger-sized female carries the male to a low point in the leaf litter where she digs a shallow burrow in the loamy soil in which to lay eggs. After water accumulates in the nest and surrounding area, motile larvae emerge from the jelly capsule indicating that hypoxia is a trigger for larval emergence. The authors hypothesize that the species is limited to this short window of reproduction because the low oxygen and high acidity of the swamp water requires larval development to be fast and to occur early in the monsoon season. Because the species is highly dependent on Myristica swamp environments, which are critically endangered, they are especially at risk from climate change. (AChang)
Isthmohyla pseudopuma by Angel Solis
December 3, 2018: We have entered a new epoch – the Anthropocene – in which human activities play a dominant role in governing Earth processes. Well-curated museum collections offer the unparalleled potential to study the origins and spread of infectious disease, the biological impact and presence of contaminants over time, physiological stress, and species range shifts due to human activities. Schmitt et al. (2018) discuss the myriad ways researchers have used museum collections to this effect and highlight the critical need to continue building and maintaining collections to understand ongoing environmental change. Of their examples, they illustrate how beautifully-curated collections have provided exceptional evidence that the fungus Batrachochytrium dendrobatidis has been widely dispersed by humans and is a causative agent of many amphibian declines globally. Although contemporary specimen collection is regularly criticized, it is imperative that scientists continue collecting new specimens and that they do so across space and time. Schmitt and colleagues further urge museums to diversify their specimen types (e.g., skeletons, skins, fluid-fixed, and tissue samples from multiple organs) and to intensify the detail and accessibility of specimen metadata. These specimens will be critical for future researchers to understand further environmental change. (MLambert)
Eleutherodactylus brevirostris by S. Blair Hedges
November 26, 2018: Haiti has experienced rapid deforestation. A new report in PNAS (Hedges et al 2018) finds that forest cover was reduced to 4.4% in 1988 to 0.32% in 2016, and 42 of the country's highest mountains have lost all primary forest. Mass extinction of wildlife, notably frogs, is taking place. All primary forest is forecast to be lost by 2035. Clearing of forests for agriculture has taken place for centuries, but as the forest has reduced the final blow is being delivered by charcoal production, in response to local demand. Haiti has the largest proportion of endangered amphibians on earth; of its 57 species, 52 have been evaluated and 30 are listed as critically endangered. Another 12 are endangered and others are too poorly known to evaluate. Recent detailed surveys of six mountains with forest and four without found dramatic losses with deforestation. Several unnamed species were discovered, already at risk of extinction. (DW)
Ambystoma maculatum by Matthew L. Niemiller
November 19, 2018: As a disease vector, it is important to control mosquito populations. However, biological control with introduced mosquitofish (Gambusia affinis) has the unintended consequence of altering ecosystems. Watters et al. (2018) explored the effectiveness of using native amphibian larvae in Missouri instead. They found that Leopard frogs (Rana sphenocephala), while consuming a large number of mosquito larvae, ate fewer mosquitos than mosquitofish. The Spotted Salamander (Ambystoma maculatum), on the other hand, consumed as much mosquitos as mosquitofish. Moreover, there was a positive relationship between mosquito consumption and salamander larvae body size providing encouragement to assess more native amphibians for mosquito control. However Thorpe et al. (2018) indicate other considerations. They found a body size-dependent response to varying prey densities. With small African Clawed frog (Xenopus laevis) tadpoles, a type II functional feeding response is shown, increasing feeding rates with prey density until a threshold when the predator cannot keep up with the prey, while larger tadpoles exhibit type III response, characterized by lower than expected feeding rates at low and high densities but increasing feeding rates at increasing intermediate densities. This suggests a need for size diversity in biological control. (AChang)
Odorrana margaretae by Yu Zeng
November 12, 2018: Ring species, complexes of populations that differentiate genetically around a natural barrier, should be relatively common based on the large array of natural conditions suitable for their formation. So their rarity may be due to scientists discovering only isolated parts of rings and not recognizing the piecemeal parts for the whole. The Sichuan Basin in China is a predicted site for ring species formation, and a new paper by Qiao et al. (2018) argues that the frog complex Odorrana margaretea is a ring species. The species has a ring-shaped distribution and the chain of populations maintains a mostly gradual and continuous genetic connection, except where differentiated populations meet secondarily in the northwestern part of the ring. Two refugial components are thought to have separated, differentiated and later reconnected. In the southeast, a genetic "melting pot" occurs in the secondary contact region, but in the northwest there is partial reproductive isolation, supporting the ring-species hypothesis. (DW)
Rana catesbeiana by William Flaxington
November 5, 2018: Invasive species can harm native ecosystems by providing a pathway for pathogen invasion. For amphibians, the most devastating pathogen is the chytridiomycete fungus Batrachochytrium dendrobatidis (Bd). A study by Yap et al (2018) shows a link between the introduction of the American bullfrog (Rana catesbeiana) and the spread of Bd in western North America. Using museum records, the study found that American Bullfrogs arrived in the same year or prior to Bd in most (83%) western watersheds that had data for both species (n=603 watersheds), suggesting that Bd-GPL in North America may have originated in the eastern US, and bullfrogs may have facilitated Bd invasion in the western US. They show in a suitability model which integrates habitat suitability and host availability, that watersheds with non-native R. catesbeiana in the mountain ranges of the West Coast have the highest disease risk. More studies that use archived specimens from natural history collections are needed to test invasion hypothesis of Bd globally. Read an adaptation of this study as teaching material for high schoolers in Science Journal for Kids (pdf). (VV)
Sachatamia albomaculata by Alberto Sanchez-Vialas
October 29, 2018: The die-offs observed in the amphibian communities of Panama are a well-studied example of catastrophic Bd-related declines. Now that Bd (or Batrachochytrium dendrobatidis) in Panama is enzootic, it remains to be seen how and if certain amphibian species can recover in the face of ongoing Bd exposure. A recent study by DiRenzo et al. (2018) combined contemporary amphibian surveys with a novel modeling approach to describe a pattern of eco-evolutionary rescue promoting host-pathogen coexistence. They show that for persistent species there is no difference in survival rate between infected and uninfected amphibians. Additionally, they found that Bd transmission was highest in areas of low amphibian abundance. While some species are persisting in Panama, amphibian species richness is approximately 40% lower than pre-Bd conditions. This study makes important strides in using statistical modeling to describe the dynamics of recovering amphibian communities. (AByrne)
Microhyla fissipes by Devin Edmonds
October 22, 2018: Given the diversity of amphibian species, more amphibian model organisms are sorely needed to address fundamental questions in developmental biology, regeneration, toxicology, genetics, and human disease research. However, most anuran model organisms are Xenopus species that are not representative of most frog life histories or biology. In a well-argued paper, Liu et al. (2016) recommended Microhyla fissipes as a new model organism because of its small size, ease of its husbandry, large clutch size, and transparent tadpoles that allow for direct observation of development. Additionally, as a member of the suborder Neobatrachia, M. fissipes is a better representative of 95% of extant frog species. Researchers are now creating inbred lines of Microhyla fissipes and creating standards for feeding and breeding this species. In preparation for future experimental designs, Wang et al. (2017) has also published a detailed embryonic development table for the species. (AChang)
Triturus marmoratus by Wouter Beukema
October 15, 2018: Few long-term studies explore the effects of infectious disease and climate change on amphibians. A new study in the high alpine amphibian communities of central Spain (Bosch et al 2018) reports on the results of an 18-year survey where amphibians have been exposed to both climate warming and the emergence of chytridiomycosis. This study shows ongoing impacts of chytridiomycosis on two of the nine species and climate effects on four of the nine species. Their data suggest a decreasing effect of chytridiomycosis, and an increasing positive effect of climate. They caution, however, that the net positive effect of climate change will turn negative as amphibian breeding habitat become unavailable as water bodies dry, a pattern that may already be underway. (VV)
Necturus punctatus by Todd Pierson
October 8, 2018: Amphibians have some of the largest and smallest known genomes of all tetrapods. Liedtke et al. (2018) shows that, although genome size is incredibly variable across amphibians, the majority of amphibian genome size evolution has occurred gradually over time. The best supported evolution model for genome size shows a single jump in size occurring as genome size increased in the ancestor of salamanders. Salamanders have the largest amphibian genomes, with the Neuse River Waterdog (Necturus lewisi) holding the title for largest tetrapod genome size (140 pg)! Furthermore, they found no support for the hypothesis that amphibian genome size evolves in association with changes in development (shifts such as changes from larval to direct development) but did see an association between genome size and length of development and climate (temperature and humidity). Despite amphibians having the widest range of tetrapod genome sizes, the evolution of genome size in this group can be largely explained by random, gradual change over time and appears to have little to do with the drastic changes in development that have repeatedly evolved within amphibians. (MWomack)
Rana pretiosa by Stephen Nyman
October 1, 2018: Is global climate change affecting amphibian communities now and is it likely to affect them in the future? A group of North American amphibian biologists ( Miller et al. 2018) used a demographic approach to study time-series data of 81 species of amphibians. The goals were to quantify the relationship between climate and local population dynamics together with factors that determine such relationships, and to assess the likelihood that rate of decline in amphibians might be explained by recent climate changes. The wide-ranging, phylogenetically informed analysis concluded that changing climate, while not the proximate cause of declines, is a strong predictor of the declines in local species in some regions. While the interpretation of the results is difficult, changing climate does explain why some populations are declining faster than others. (DW)
Guibemantis milingilingy by Miguel Vences
September 24, 2018: New species of amphibians continue to be named at a pace of about 3 per week. Many of the newly described species are from well-explored regions, where they have been found in narrowly limited habitats. Examples are Eurycea sublavicola from a few hundred m of stream in Arkansas, USA, Hynobius tosashimizuensis, known only from about 0.35 km2 on Shikoku Island, Japan, Hypogeophis montanus, a small caecilian known only the highest elevations (above 700 m) of the Island of Mahe, Seychelles, where the total dimensions of its range are about 1 x 2 km. Guibemantis milingilingy is known only from a tiny area above 2000 m near the peak of Marojejy in northern Madagascar, where it lives and reproduces in frond axils of Pandanus plants. Many new frogs of the genera Proceratophrys and Brachycephalus from Brazil have apparently tiny geographic ranges. Lesser studied areas, such as the Peruvian highlands, continue to produce apparently small-ranged species of Pristimantis and Phrynopus. These reports suggest that the rate of species description is unlikely to drop anytime soon. (DW)
Duellmanohyla soralia by Todd Pierson
September 17, 2018: Disease-causing pathogens are significant contributors to amphibian population declines. A recent review (Blaustein et al 2018) summarizes experimental studies that assess effects of three pathogens (Batrachochytrium dendrobatidis, B. salamandrivorans, and ranaviruses) on amphibian hosts. It includes experimental studies in the laboratory, in mesocosms, and from the field as well as experiments on the interactive effects of these pathogens with other contributors of amphibian declines. Though well-designed experimental studies are critical for understanding the impacts of disease, inconsistencies in experimental methodologies limit our ability to compare and draw conclusions. Studies found host susceptibility varies by species, host age, life history stage, population and biotic (e.g., presence of competitors, predators) and abiotic conditions (e.g., temperature, presence of contaminants), as well as the strain and dose of the pathogen, to which hosts are exposed. The review suggests the importance of implementing standard protocols and reporting for experimental studies of amphibian disease. (VV)
Hyla cinerea by John White
September 10, 2018: Langowski et al. (2018) revealed new insights on the biomechanics of how frogs attach to (and detach from) surfaces by examining the toe pads of the American Green treefrog (Hyla cinerea) with new technologies. Using a combination of histology, immunohistochemistry, and synchrotron micro-computer-tomography (l-CT), the researchers obtained an extremely detailed 3-D characterization of tree frog toe pads. All toe pads examined shared a general layout with a ventral collagen layer, collateral ligaments, a septum compartmentalizing the subcutaneous volume into a distal lymph space and a proximal gland space, and muscular structures. Perhaps most interestingly, the collagen layer can withstand a shear load of up to 6.5 N! Furthermore, the researchers hypothesize that the septum facilitates proximal peeling of the pad and detachment from surfaces. With this new knowledge, researchers can better explain the mechanics and physics behind frog climbing and expect that frog toe pads will help design biomimetic adhesives. (MWomack)
Hylorina sylvatica by Richard D. Sage
September 3, 2018: Since January 2004, AmphibiaWeb has posted a monthly list of the latest scientific papers in amphibian declines. This immeasurably useful service was performed by Dr. Tim Halliday. Tim Halliday was the international director of the DAPTF, Declining Amphibian Populations Task Force, which was founded in 1990 and was pivotal in many of the international, national and regional coordinations in amphibian conservation to this day. His lifelong devotion to amphibians is best reflected in his beautifully illustrated Book of Frogs and his colorful original artwork. We are sad to announce that Tim, after a long tenure with AmphibiaWeb, will be stepping down from his monthly contributions. We are grateful for his AmphibiaWeb service and wish him well. Tim, we thank you sincerely.
Indotyphlus maharashtraensis by Varad Giri
August 27, 2018: Filling in needed data on the distribution of chytrid in Asia, Thorpe et al (2018) report on their systematic survey of the lethal pathogen Batrachochytrium dendrobatidis (Bd) in the Western Ghats, a biodiversity hotspot in western India. Taking account of the topographic heterogeniety of the region, they surveyed Bd in amphibians comparing habitats and elevations, from rocky plateaus to coastal area, and different factors such as connectivity, edaphic and climatic conditions, and anthropogenic impacts. They found Bd in 15 out of 21 species including the first records in caecilians in India, the Critically Endangered Xanthophryne tigerina and Endangered Fejervarya sahyadris. Although no individuals had external signs of chytrid, they suggested the low overall prevalence to be signs of an historic infection. Bd prevalence tended to be highest in proximity to human disturbance regardless of elevation and related factors; the authors caution that transmission is still a vital but poorly known factor in Bd infections. (MK)
Bufo spinosus by Alberto Sanchez-Vialas
August 20, 2018: Identifying the biological mechanisms underlying seasonality in infection can enable better prediction and prevention of future infection peaks. A study by Daversa et al (2018) tracked Spiny Common Toads (Bufo spinosus) within and across annual cycles to assess seasonal variation in movement, body temperatures and infection from the fungal pathogen, Batrachochytrium dendrobatidis (Bd). Across annual cycles, toads did not consistently sustain infections but instead gained and lost infections from year to year. Radio-tracking data showed that infections were lost after breeding migrations and pronounced seasonal variation in toad body temperatures may be the reason. This study provides evidence of migratory recovery (i.e., loss of infection during migration) in a wild populations and may help explain differences in susceptibility to Bd. (VV)
Rana boylii by Stephen Nyman
August 13, 2018: Rana boylii, the Foothill Yellow-legged Frog of Oregon and California, is a declining species considered to function as a "sentinel" for assessing ecological health of stream ecosystems. Its phylogeography was studied using a large dataset (RADseq) in a landscape genomics approach (McCartney-Melstad et al. 2018). The five primary clades are extremely differentiated, with about half of the range occupied by a rather genetically uniform population. The peripheral clades are hierarchically substructured and should be treated as separate management units for conservation purposes (rather than previous watershed units). The species is apparently extinct in southern California and the southwestern-most peripheral clade in Monterey County is near extinct and shows the lowest genetic diversity. This study finds Foothill Yellow-legged Frog to be one of the most genetically diverse frog species and points the way for improved species recovery targets. (DW)
Ensatina eschscholtzii by Heidi Rockney
August 6, 2018: Which explains skin microbiome variation in amphibians, microhabitat or taxonomy? Bird et al (2018) explored this in Ensatina and Batrachoseps species, predicting that more genetically related host populations would have more similar microbiomes than more distantly related populations. They found overall (alpha) diversity in microbes differed among Ensatina in all clade groups, and between Ensatina and Batrachoseps. Species composition (beta) diversity differences between Ensatina lower clades were not correlated to host genetic distances, and salamander identity at higher taxonomic levels (genus and Ensatina higher clades) was a weak predictor of microbiome composition. They observed overlap in the microbial species on salamander skin and in surrounding soil, but the relative representation of those species differed significantly. They conclude that environmental factors, rather than host traits, are likely driving these salamander microbiome assemblages. (VV)
Ranitomeya reticulata by Evan Twomey, BIOWEB
July 30, 2018: AmphibiaWeb announces a new working relationship with the outstanding Ecuadorian online biodiversity project BioWeb Ecuador. Accounts for all Ecuadorian taxa can be accessed under an "Anfibios del Ecuador" tab, for any of the currently recognized 615 species recorded from the country. These Spanish-language accounts are thorough and include up-to-date information on conservation status and phylogenetic relationships. Point locations from El Museo de Zoología de la Pontificia Universidad Católica del Ecuador (QCAZ) are mapped on the background of a MAXENT-based models of expected distribution. Superb photographs are designed to show anatomical details in addition to the portrait quality general views. Ecuador has a megadiverse amphibian fauna, ranking fifth among all countries but a strong first of the top ten in species per unit area. AmphibiaWeb thanks our Ecuadorian colleagues, led by Santiago Ron, for this superb contribution to open access information on amphibians. (DW)
Plethodon metcalfi by John P. Clare
July 23, 2018: How will salamanders deal with climate change? A new experimental study (Riddell et al. 2018) found that plethodontid salamanders show remarkably plastic responses to ecological conditions, which bode well for anticipated increases in climatic temperatures. The study integrated experimental physiology and behavior into a mechanistic species distribution model and predicted extinction risk based on the capacity of individual salamanders to maintain energy balance both with and without plasticity. The important conclusion is that incorporating plasticity fundamentally alters ecological predictions by reducing risk of extinction. These findings help understand how salamanders in the southern Appalachian biodiversity hotspot dealt effectively with Pleistocene climatic events. They likely "sheltered in place", as suggested by the many phylogeographic studies showing substantial geographic structuring of genetic variation. (DW)
Dendrobates tinctorius by Hugo Claessen
July 16, 2018: The startlingly bright colors and intricate patterns of Neotropical poison frogs are icons of warning coloration. Barnet et al. (2018) show in a recent paper that at least in Dendrobates tinctorius, the bright color patterns may simultaneously scream "Here I am!" to nearby would-be predators, yet be relatively undetectable to predators farther away. They measured the frog’s complex patterns of yellow and blue on a black background as perceived by different types of potential predators (reptiles, birds, mammals). Using a machine learning algorithm, they assessed the ability of different visual systems to discriminate D. tinctorius from a leaf litter background at different distances. Close up, discrimination by each visual system was highly accurate, but far away, discrimination declined dramatically. In the field, they used model frogs with different color patterns to show that cryptic (brown and black) models had fewer predation attempts against a natural leaf-litter background, whereas background did not affect the attack rates on purely aposematic (bright yellow) models. The tinctorius color pattern also had lower attack rates against the natural background, indicating an element of protective camouflage. Experiments with human "predators" trying to find frogs on a computer screen showed the tinctorius color pattern was just as aposematic as the bright yellow morph close-up, but from a distance was just as hard to see as cryptic coloration. They conclude a kind of perceptual averaging occurs, in which the different colors of the intricate pattern blend together at a distance, making the frogs virtually invisible in their natural background. (KSummers)
Bolitoglossa splendida by Alex Monro and Eduardo Boza Oviedo
July 9, 2018: Conservationists make surprisingly little use of the extensive records of extinction of taxa in the fossil record. Tietje and Roedel (2018) make use of fossil-based models to predict the extinction risk of living species of amphibians. Data for 354 extinct taxa were obtained from the Paleobiology Database and for living taxa from AmphibiaWeb and IUCN Red Lists. A fossil-calibrated model predicted durations of living amphibians in succession from Least Concern (LC) to Extinct (EX). LC species have a median predicted duration twice that of Near Threatened (NT) species and four times that of other IUCN categories. Importantly, Data Deficient (DD) species were predicted to have a median duration that was most similar to that of Critically Endangered (CR). Unfortunately, in excess of one quarter of all amphibians, including most recently named taxa, are considered to be DD. (DW)
Anaxyrus californicus by Sam Stewart
July 2, 2018: How amphibians will respond to ongoing climate change is uncertain and doubtless will vary among taxa and environments. A study of the Arroyo Toad (Anaxyrus californicus) examined skeletochronology and marked populations to determine age of individuals and age-related population structure of local populations in their environment in coastal southern California (Fisher et al. 2018). This area is affected by periodic multiyear droughts. Age structure of populations of toads in areas of predictable water availability is younger than for areas of surface water unpredictability. The toads are estimated to live seven to nine years. This means that periods of extreme drought, extending across a number of consecutive years, might surpass the life span of frogs. Amphibians such as Arroyo Toads are thus vulnerable to local and regional extinction in ephemeral freshwater systems. (DW)

Plethodon punctatus by Will Lattea
June 25, 2018: Markle and Kozak (2018) determined the mean critical thermal maximum (CTM) and mean acclimation ability of 16 species of Desmognathus and eastern Plethodon in order to determine how acclimation ability relates to geographic range size. All had comparable CTM, from 31.7 to 33.1 celsius but varied substantially in acclimation ability. They measured standard metabolic rates at three different temperatures and conducted a phylogenetically informed analysis. Wider ranging salamanders display greater acclimation ability than those with smaller geographic ranges. The authors suggest that this greater physiological advantage may have been an important factor in the expansion of range sizes and is likely to provide greater protection from extinction. (DW)

Bufo gargarizans by Todd Pierson
June 18, 2018: In homoeothermic (or internally regulated, warm-blooded) animals, the link between larger brains and longer lives is well established. Slower development may be linked to better homeostasis and increased cognition, which in turn increases chances of survival. Yu et al (2018) sought to explore this relationship in brain size in an ectothermic group, namely frogs, where it has been a mystery. After controlling for the effects of shared ancestry and body size, they found a positive correlation between brain size, age at sexual maturation, and life span across 40 species of frogs. Moreover, the ventral brain regions, including the olfactory bulbs, are larger in long-lived species. They showed with their frog study that the relationship between life history and brain evolution follows a general pattern spanning vertebrate groups. (MK)

Rana sylvatica by Todd Pierson
June 11, 2018: Nitrogen balancing in amphibians is important for osmoregulation, cryoprotection, and metabolic inhibition. In some vertebrates, gut bacteria aid this balance by producing urease, an enzyme that breaks down urea. However, until recently it was unknown if gut bacteria played a role in amphibian nitrogen-recycling. Wiebler et al. (2018) investigated the role of hindgut microbiomes in Rana sylvatica, a frog known for storing urea during its hibernation in the winter, by comparing the urease activity and microbial community in hibernating males with active males and by artificially increasing the concentration of urea in the blood stream. They found that while active frogs have a greater concentration of bacteria in their hindgut, hibernating frogs have a greater diversity of bacteria that produce urease, and have more urease activity. Additionally, increasing the concentration of urea in the blood stream increase bacterial urease activity. They provide the first report of nitrogen-recycling by hindgut bacteria in amphibians and encourages more study to determine the role of gut bacteria in the osmoregulation of other amphibians. (AChang)

Andrias davidianus by Benjamin Tapley
June 4, 2018: Giant salamanders in China are in trouble because of a combination of exploitation for food and intense captive breeding activities that have mixed genetically distinct groups across its known range. Yan et al. (2018) shows that the animals currently known as Andrias davidianus should be split into at least five different cryptic species. Chinese giant salamanders have been farm-raised for their meat with the government encouraging the release of some individuals in a misguided conservation attempt. However, the farm-raised individuals were bred without consideration of genetics and their release could result in the loss of genetic distinctness, merging the five species into one. Further Turvey et al. 2018 presents a dismal picture of the current status of wild populations; despite intense field work, a seasoned group of biologists were only able to find no more than a handful of individuals. Governmental action will be required to preserve those few wild populations that still exist. (DW & AChang)

National Geographic video
May 28, 2018: Hopping and jumping are among the most characteristic ways that most living frogs get around. While some features of the skeleton that are associated with this form of locomotion can be gleaned from fossils, there is very little direct evidence of hopping in the fossil record of frogs. Recent work from Park and colleagues (2018) provides the first well-studied example of frog trackways based on Late Cretaceous deposits on Saok Island in South Korea. Approximately 65 tracks representing 16 trackways show impressions of the hands and feet of frogs both walking and hopping. These tracks reveal that these relatively small frogs (probably less than an inch in length) were already accomplished hoppers, moving through the air at least six times their body length. (DB)

Nanorana parkeri by Kai Wang
May 21, 2018: One of the first frogs to have its whole genome sequenced is Nanorana parkeri, a Tibetan frog that breeds at elevations from 2,800 m to almost 5,000 m, making it perhaps one of the highest elevation frogs. A research team has used availability of its genome to study variation along geographic and elevational gradients (Wang et al. 2018). Genomes were obtained from 63 individuals and used to study adaptation and species formation. Selection was detected in 579 highly divergent genomic regions, involving 365 genes in 51 functional classes. High altitude adaptation was evidenced in genes associated with blood circulation, response to hypoxia and UV radiation. Such adaptation plays a significant role in maintaining and driving continued divergence, even leading to reproductive isolation. The paper opens a new era in the study of genomics of natural populations of amphibians. (DW)

Bombina orientalis by Pierre Fidenci
May 14, 2018: A multinational research team (O’Hanlon et al 2018) has concluded that the infamous chytrid fungal pathogen of amphibians (Bd) likely originated on the Korean peninsula (or nearby area) and spread nearly world-wide recently. The largest number of discrete genetic lineages, including the Global Panzootic Lineage of Bd (BdGPL, the invasive, hypervirulent form), are found there. Bd seems to have little trouble spreading; all variants have been found in the commercial trade. A surprising finding is just how rapidly the invasion occurred -- within the 20th century. BdGPL is estimated to have originated between 120 and 50 years ago, and yet it was detected in relatively remote parts of Central America as early as 1972. Accordingly, this is receiving much notice: Lips (2018) describes its wide-ranging implications and National Geographic also reports on its findings. (DW)

Hydromantes samweli by Robert Hansen
May 7, 2018: The Shasta Salamander complex (Plethodontidae) in northern California long has been known to display substantial genetic diversity, even though its total distribution occurs within an 850 km2 polygon (119 km2 of that space occupied by Lake Shasta). A new analysis (Bingham et al. 2018) finds that description of two new species, Hydromantes samweli and H. wintu, is warranted. The three species comprising the complex (including H. shastae) are morphologically cryptic forms that differ in some morphometrical details but are very distinct in allozymes and DNA sequences, and they are habitat-restricted to mainly limestone outcrops in a region that experiences very high summer temperatures and requires underground refugia. Plans to raise the current Shasta Dam will result in the loss of significant habitat for these three salamander species. (DW)

Pseudophilautus procax by Peter Janzen
April 30, 2018: A recently published paper (Nowakowski et al. 2018; see Pyron 2018) examines the impact of habitat conversion on amphibian abundance and representation in communities. While there are both winners (which gain in abundance) and losers (reduced in abundance and driven eventually to extinction), the former are overrepresented in modified landscapes. 81% of species studied declined in abundance where habitats were converted, while only 19% increased. Species with specialized life histories and narrow microhabitat requirements saw strong decreases (e.g., tropical salamanders 4X decrease; rhachophorid frogs 28X decrease; terrarana frogs 6X; all direct developing). Species might survive in rice paddies or cow pastures, or show other features that predispose them for human coexistence. Within communities, sites lost 2 to 11 species on average and 66% decreased in evolutionary history (this is a phylogenetically informed analysis). Strong phylogenetic homogenization is in progress. Identifying especially sensitive clades should be an important priority in conservation strategy. (DW)

Siamophryne troglodytes by Nikolay A. Poyarkov
April 23, 2018: Many new species result from splitting existing species; novel, distinctive frogs are rare. An exception is Siamophryne troglodytes, a new genus and new species of microhylid frog endemic to a single limestone cave of Thailand (Suwannapoom et al 2018). More unusual, few frogs are cave dwellers, and Siamophryne shares many features of troglodytes: large eyes, long limbs, with slender digits and expanded digital tips. In contrast, most microhylids are squat with short limbs and small eyes. What is equally interesting is its biogeography. Siamophryne is mostly closely related to Gastrophrynoides from the Malay Peninsula and Borneo. Gastrophrynoides in turn is the sister-group of a diverse clade of Asterophryinae, a group endemic to the Papuan region and southern Phillipines. Thus, Siamophryne and Gastrophrynoides connect the mainland to a diverse endemic archipelago lineage. (DC)

Ameerega trivittata by Paulo Roberto Melo-Sampaio
April 16, 2018: There is mounting evidence that most amphibians are pretty good at finding their way home. Recently, Pašukonis et al. (2018) strapped tiny radio transmitters to Three-striped Poison Frogs (Ameerega trivittata) to see how well they could navigate back to their home territories after being moved different distances. Ameerega trivittata are particularly interesting to study because they lay their eggs on land and once they hatch, adult males move their tadpole young via piggyback to bodies of water. Thus, Ameerega trivittata may be especially talented at finding their way around the forest. The researchers found that even when the frogs were moved further away from their home than they would normally travel, the frogs could navigate straight back to their home territory. This means the frogs may have a map-like navigation system; however, it is still uncertain what cues from the environment the frogs use to find their way home. (MWomack)

Colostethus panamensis by Alberto Sanchez-Vialas
April 9, 2018: Amphibians in Panama have experienced declines for over a decade due to the disease chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd). In Science, Voyles et al. (2018) documents the recovery of frogs in Panama despite continued virulence of the pathogen. The study shows that frog defenses have improved across multiple species by comparing Bd-inhibition of skin secretions collected before the Bd outbreak and more recently. Additionally, they conducted infection experiments, lymphocyte challenge assays, and whole genome sequencing on Bd isolates collected from Panama during the Bd outbreak and 10 years later. They found that the pathogen is as deadly as ever, pointing to host factors driving population recoveries over a relatively short period of time. Despite not using live infection experiments to connect the effect of skin secretions to frog survival, the authors argue their data provides evidence for just one of many host-mediated factors that may be contributing to frog recoveries. They emphasize monitoring and protecting small remnant populations as an important conservation priority and argue that studying recovering populations will allow for more informed strategies to combat this ever-present, deadly disease. (AByrne)

Babina daunchina by Jing Che
April 2, 2018: Xue et al. (2018) recently revealed in frogs the brain regions that are responsible for allocating attention to important sounds. Animals encounter a wide variety of sounds in their environment but some sounds are more important and catch our attention more readily than others. In other animals (mammals, birds, and other tetrapods) the forebrain plays an important role in drawing attention to important sounds in the environment; however, amphibians have a far less developed forebrain. Xue et al. show the telencephalon may mediate attention to mating calls in frogs. In music frogs (Babina daunchina), males call from underground burrows to attract females and these calls are an important mating signal. Further, they found males and females differ in the neural connections responsible for sound attention, perhaps reflecting differences in mating strategies between the sexes. When male music frogs call, other males may prepare to respond/compete. Meanwhile, females dynamically assess and monitor many acoustic cues, perhaps enabling females to choose the best mate. (MWomack)

Leiopelma archeyi by David C. Cannatella
March 26, 2018: Archey’s frog (Leiopelma archeyi) is considered one of the most endangered and evolutionarily distinct frogs in the world. This small frog occurs in the moist, subalpine scrub of New Zealand’s North Island in the Coromandel Peninsula and the Whareorino Forest, and is known for its direct developing young (having no tadpole stage). In March 2018, New Zealand’s Department of Conservation will proactively combat one of the threats to the frogs by setting out over a thousand self-resetting rat traps in Whareorino Forest. The deployment of automatically resetting rat traps apparently has the benefit of reducing the need for human intervention which allows long unsupervised implementation as well as reducing the exposure of the tiny frogs to human-transmitted diseases in these remote areas. The NZ Department of Conservation has shown that reducing introduced predators such as rats has allowed frog populations to stabilize and do well in translocated areas like Pureora, south of the Coromandel Peninsula. (MK)

Salamandra lanzai by Wouter Beukema
March 19, 2018: In the race to prevent the spread of Batrachochytrium salamandrivorans (or Bsal), a fungal pathogen deadly to salamanders, scientists have been investigating its ecology and host-pathogen dynamics. Spitzen-van der Sluijs et al. (2018) report that Bsal may be a poorer disperser than previously thought; they found no evidence of Bsal spreading between two adjacent fire salamander subpopulations after several years. From lab experiments, they conclude that direct contact with infected hosts/vectors is a more likely pathway of disease spread compared to passive dispersal (e.g., through water) by Bsal. The authors suggest that biosecurity measures target human-mediated Bsal movement. The European Union recently set forth new health protection measures in salamander trade, such as requiring animals to have Bsal-free certification prior to importing. This policy action formalizes steps towards a clean(er) trade program. (TYap)

Hypsiboas faber by Leonardo de Souza Machado
March 12, 2018: Frogs occupy many different microhabitats, from underground burrows to the tops of the tallest rainforest trees. In a broad comparative study, Citadini et al. (2018) wanted to better understand how limbs and locomotion varied among frogs that occupy different microhabitats. The authors examined limb evolution and quantified maximum jumping distance for 64 frog species from Brazil and Australia. They found that torrent, arboreal, and semi- aquatic frogs tended to have longer hindlimbs and jumped farther whereas fossorial and terrestrial species often had shorter hindlimbs and jumped less far. Citadini et al. support the overall hypothesis that limb evolution plays an important role in allowing frogs to occupy such a large range of microhabitats. (MWomack)

Incilius fastidiosus by William E. Duellman
March 5, 2018: Often we overlook the untold human side of amphibian declines. Dr. Karen Lips was one of the first biologists to witness and document amphibian extinctions. In this open access article, she not only recounts her personal experiences surrounding the circumstances that led her to be in Central America during a mass extinction of amphibians, but she also gives her point of view on what we can expect for the future of amphibian conservation. The Pico Blanco Toad, Incilius fastidiosus, was the focus of her early field work and is now listed as Critically Endangered. (VV)

Rana sylvatica by John White
February 26, 2018: The costs and benefits of phenotypic plasticity, the ability for organisms to change a trait in response to their environment, has long been of interest to evolution research. However, we lack understanding of how plastic traits evolve in a broad phylogenetic context. Relyea et al. (2018) examined plasticity in a broad comparison of the embryos of 19 amphibian species, spanning three families and five genera by exposing them to two predator cues (crushed egg and predatory crayfish) and a control. Five life-history traits (hatching time, stage at hatching, mass at hatching, development rate, and growth rate) were tracked and compared across species to see if and how plasticity exhibits a phylogenetic signal. The responses from the different species varied greatly; phylogenetic signals were found in many traits. However, it was rare for phylogenetic signaling to be found for trait plasticity. Using a best-fitting trait-evolution model (Ornstein-Uhlenbeck), the authors found that in three traits the plasticity evolution rate was higher than the trait evolution rate, while in the other two, the plasticity evolution rate was lower. The results provide evidence that constraints on the evolution of life-history traits of amphibian embryos is based more on phylogenetic position than the evolutionary rate of plasticity. The trait-evolution model also suggests that the traits examined may be at an adaptive optima with their plasticities. (AChang)

Ambystoma mexicanum by John P. Clare
February 19, 2018: The axolotl is the most common salamander used in biological research; they are easily bred, and thousands live in home aquariums and labs. Its long association with humans is fascinating. In the 13th century, the indigenous Mexica people built an island city in Lake Texcoco in the Central Valley of Mexico. They also built floating gardens and canals, which the native axolotls invaded. Eventually, the lakes were drained and the salamanders were cut off. Their numbers declined; a 1998 census found 6,000 axolotls per square kilometer. In 2000, Luis Zambrano, a biologist at the Universidad Nacional Autónoma de Mexico, found only 1,000 animals/km2. By 2008, the census registered 100/km2, and currently the estimate is only 35/km2. With isolation, reduction in numbers, invasive predators, and environmental contaminants, the axolotl is almost extinct in the wild. (DCC)

Leptodactylus pentadactylus by Ignacio de la Riva
February 12, 2018: Heteromorphic sex chromosomes refers to sex chromosomes that differ in appearance and amount of genetic material. The traditional model of species exhibiting heteromorphic sex chromosomes is that they only have two pairs of sex chromosomes. While this is the common model in birds and mammals, amphibians are known to have a greater variation in sex determination from some species not exhibiting heteromorphic sex chromosomes at all to others with the traditional model of pairs. Gazoni et al. (2018) characterized the chromosomes of six female and seven male Leptodactylus pentadactylus, collected from the wild. They found that of the 11 pairs of chromosomes that the species has, more (six) pairs are sex chromosomes than autosomal. Among vertebrates, this is the largest number of sex chromosomes known in a species. Evidence also suggests that L. pentadactylus is part of a larger species complex and their findings may represent the effect of chromosomal rearrangements in the evolutionary process. (AChang)

Oophaga pumilio by Brian Freiermuth
February 5, 2018: Why do distinct morphological forms, like color patterns, persist in some species? One idea contends that male-male competition may maintain polymorphisms if aggression tends to be stronger towards similar, or towards common, morphs. The strawberry poison frog (Oophaga pumilio) is well-known for the extreme color variation between island populations in the Bocas del Toro Archipelago of Panama, and also exhibits within-population polymorphism in parts of the archipelago. Yang et al. (2018) used populations with blue and red and intermediate morphs to test this hypothesis. They used frog models (complete with moving platform and acoustic backup) to challenge territorial males in two monomorphic populations (blue and red), and two polymorphic populations (one with a predominance of blue, and the other red). While males in each monomorphic population showed more aggression towards their own color morph (consistent with predictions), in the polymorphic populations, aggression was higher towards the blue morph in both cases (defying predictions). The authors conclude aggression towards the opposite (or most common) morph was unlikely to explain the maintenance of polymorphism in this system. One open question is whether this within-population polymorphism is, in fact, stable, but we may have to wait a long time to confirm this. (KSummers)

Odorrana andersonii by Wang Lijun
January 29, 2018: Cathelicidins are a family polypeptides, known for their antimicrobial properties, that are found in immune and skin cells. About 30 cationic peptides have been isolated in various vertebrates. However, despite amphibians being known for their complex skin polypeptide secretions, only seven cathelicidins have been identified from five amphibian species. Cao et al. (2017) recently isolated a new cationic peptide, Cathelicidin-OA1, from Odorrana andersonii that possess antioxidant properties but no antimicrobial properties. Furthermore, experiments with Cathelicidin-OA1 on mouse models revealed full-thickness skin wound healing properties, which is a first for amphibian cathelicidins. Cathelicidin-OA1 promoted wound-healing by increasing macrophage recruitment to wound sites, resulting in faster skin cell production and tissue formation. These findings help us better understand this family of polypeptides and promise the development of better wound-healing agents. (AChang)

Rana sierrae by Devin Edmonds
January 22, 2018: The high elevation, relatively pristine lakes of the southern Sierra Nevada (California, USA) has been the scene of massive frog die-offs from chytridiomycosis caused by the fungus Bd (Vredenburg 2010). Recent advances and practices in environmental DNA surveying enabled a study by Kamoroff and Goldberg (2017) to detect Bd a month prior to a frog die-off in Sequoia Kings Canyon National Park. This strongly suggests the utility of eDNA surveying for early detection of Bd in areas thought to be susceptible to outbreaks, which may give biologists a new early warning method and time for conservation efforts. (MK)

Bolitoglossa ramosi by Mauricio Rivera Correa
January 15, 2018: Among vertebrates, adult salamanders are unique in their ability to regenerate complex tissues, such as limbs. The model organisms for limb regeneration are the Axolotl (Ambystoma mexicanum, family Ambystomatidae) and species from the family Salamandridae. The two families use different cellular mechanisms of regeneration and axolotls have very different life histories from newts as the former is fully aquatic while the latter exhibits a traditional, biphasic life cycle. Arenas Gomez et al. (2017) characterized limb regeneration in Bolitoglossa ramosi (family Plethodontidae), a fully terrestrial salamander with direct development. Among the differences in regeneration, they found that B. ramosi takes longer than other species to regenerate limbs, leading to questions regarding the relationship between limb regeneration and direct vs indirect development. (AChang)

Duttaphrynus himalayanus by Gururaja K.V. Acharya
January 8, 2018: Biodiversity survey work is a critical step to assess and monitor the state of amphibians in any given area, even protected ones. A herpetology survey conducted by Shrestha and Shah (2017) in Manaslu Conservation Area in western Nepal along the China border illustrates this in a multipronged strategy. Their survey included traditional methods such as literature review, visual encounter surveys, patch sampling and opportunistic observations combined with less commonly used ethnographic questionnaire. Of the 21 species documented by the literature, they found 5 species including a new record for the area. Of the 8 species of documented amphibians, only Duttaphrynus himalayanus was encountered in the field; three frog species were noted in interviews as popular food items. The authors note this local ‘delicacy’ could have significant impact on biodiversity and show how taking into account human use is an important part of survey work. (MK)


back to News by Year
  • December 31, 2017: 2017 has been busy for AmphibiaWeb serving a worldwide audience, an average of over 25,000 pageviews a week, over 1.3 M for the year. In 2017, we added expert species accounts from Axel Hernandez for Tylototriton and Echinotriton , updated salamander accounts from Jean Raffaelli, and, of course, species accounts by herpetology students around the US-- Look for integration of more species trait data in 2018. With the support of the US Forest Service, we launched the Amphibian Disease portal to allow researchers to archive and share their chytrid disease samples (both negative and positive), an important step to furthering our understanding of this deadly amphibian disease-- Look for Bdmaps data integration in 2018. We continue to update a comprehensive list of all amphibian species including 158 new species described in 2017-- Look for enhancements and new correlative analysis to explore this data in 2018. Check out our AmphibiaWeb Map Gallery. Thank you to all our users for your contributions and support; we wish you a Happy New Year and look forward to serving you in 2018!
  • December 25, 2017: The lowland Yellow-legged frog, Rana boylii, was present at a number of sites in southern California but has not been seen since the late 1970s. Adams et al. (2017) hypothesized that the fungal pathogen Bd was an important factor in the rapid decline. They used a unique integrative approach including analysis of museum specimens for histological or molecular evidence of Bd, examination of field books of biologists deposited in archives, interviews with field biologists, and diverse historical evidence to build an argument that is consistent with their hypothesis. The study is a novel approach and presents a methodology that may be useful in other instances of amphibian disappearances in regions affected directly and indirectly by multiple stressors, including factors associated with urbanization. (DW)

  • December 18, 2017: Frogs have evolved mechanisms that enable systemic delivery of toxic antimicrobial peptides (secreted in their skin), which are sufficiently fast-acting to evade predation. A new paper (Raaymakers et al. 2017) shows how this happens. The peptides affect the oral epithelium of predators (snakes, in this case) by making it especially permeable to toxins secreted at the same time. The toxins enter the predators’ bloodstream and organs with near instantaneous outcomes. Enhancement of absorption exists in representatives of widely divergent taxa, suggesting that it may be an ancient and general defense system in frogs. This study demonstrates previously unknown functions for these peptides thought to be important only in immune responses, and opens pathways for studying epithelial absorption, which may be particularly important in predators (such as snakes) that have some difficulty subduing struggling or inflating frogs. (DW)

  • December 11, 2017: Until 2016, the tadpoles of the frog family Micrixalidae had not been described. In their study, Senevirathne et al. (2016) provide the first in-depth description of tadpoles from Micrixalidae, a family endemic to the Western Ghats of India and known for their elaborate foot flagging courtship. Females bury their eggs in the sand of streams where tadpoles live a fossorial lifestyle, using their eel-like bodies to maneuver through the substrate. Finding food while buried can be difficult but Micrixalus herrei tadpoles thrive as "sand-eaters" that ingest sand and then feed on organic matter found among the sand grains. Tadpoles of M. herrei have a number of rare morphological traits that show convergence with other fossorial tadpoles known globally. However, M. herrei show distinction from other described fossorial tadpoles by having ankylosed ribs. We do not yet know why M. herrei tadpoles live underground but the authors propose rapid fluctuations of surface water in streams during the pre-and post- monsoon periods of the Western Ghats, extreme within-stream predator pressure, and the abundance of sub-surface food as potential selection pressures. (MWomack)

  • December 4, 2017: New species of amphibians continue to be described at a rate of about 2.9 species per week! Many of the newly discovered species lay eggs that develop directly without tadpoles and they typically have small to very small geographic ranges. Such is the case with the microhylid genus Stumpffia, endemic to Madagascar, a clade of mainly small to miniaturized frogs (a few are much larger than the others). A new paper by Rakotoarison et al. (2017) describes 26 new species based on a multidimensional analysis. The genus is highly diversified genetically as well as morphologically and there is also some variation in life history (See Stumpffia on AmphibiaWeb). Regrettably, 18 of the total of 41 species in this genus are recommended for classification as Endangered, and eight as Critically Endangered. The new species tend to come from what are literally the last wild places. (DW)

  • November 27, 2017: Chytridiomycosis, an emerging infectious disease (EID) caused by two fungal pathogens, Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal), threatens amphibian diversity. When Bd was first described in 1999, action was not taken rapidly, and a global pandemic ensued. With the recent discovery of Bsal, a second amphibian pandemic is looming. Yap et al. (2017) review what is known about Bsal since its discovery in 2013, the global efforts to minimize its spread, and regulatory gaps that impede a rapid response. The emergence of this pathogen provides an opportunity to improve global biosecurity and safeguard humans and wildlife by limiting the spread of EIDs in wildlife. (TYap)

  • November 20, 2017: The Hula Painted frog, Latonia nigriventer, was the first frog to be declared extinct by the IUCN in 1996. First discovered in 1940 in the Hula Valley, presently in northern Israel, its habitat was subject to severe disruption resulting from the drainage of marshes for agriculture. Never common, it was not seen from 1955 until its rediscovery in 2011. Intense study since that time has focused on the last remnant marshes and within two years, 13 adults were found. Perl et al. (2017) reports events since then, including the discovery of 64 adult females, 42 adult males, 29 juveniles and 40 tadpoles. The 2011 discovery was from a small nature reserve, but most of the new individuals are from a neighboring site. The occupied range is estimated to be at least 6.5 km 2 . Much descriptive information and natural history is provided including its breeding calls, and detailed description of the tadpoles. Evidence of infection by the chytrid fungus is presented, but there is no sign of negative impact, possibly because of positive effects of antimicrobial peptides. Ongoing habitat degradation remains the primary concern. Recognizing the elusiveness of the Hula Painted frog, Renan et al (2017) applied eDNA techniques, which amplifies trace DNA in the water, to detect and classify its preferred habitat. This new monitoring method is encouraging that more frogs will be found and effective protections can be put in place. (DW)

  • November 13, 2017: Genomic sequencing technology has allowed us to detect genetic structure at an unprecedented resolution. With such levels of detail comes the difficulty of distinguishing between structure associated with populations versus that of speciation events. A study by Chan et al. (2017) show that widely-used species delimitation programs erroneously recognized population structure as distinct species in a group of Torrent Frogs in Malaysia (Genus Amolops). Using a variety of genomic methods, they demonstrate that gene flow was prevalent among a number of populations that were initially identified as separate species. Their study highlights the potential misuse and abuse of popular species delimitation methods and calls for more cautious implementation of these methods especially for cryptic species that could involve gene flow. (K-OChan)

  • November 6, 2017: Spadefoot toads (Scaphiopodidae, Pelobatidae) are noteworthy for their divergent larval periods and responsiveness to pond drying. A study by Kulkarnie et al. (2017) compared hormonal variation underlying these differences. In response to pond drying, Pelobates cultripes and Spea multiplicata accelerate metamorphosis, increase standard metabolic rate (SMR), and elevate whole-body content of thyroid hormone and corticosterone. In contrast, Scaphiopus couchii, with the shortest larval period, highest whole-body thyroid hormone and corticosterone content, and highest SMR, is least affected. Their findings support the hypothesis that the atypically rapid and canalized development of S. couchii evolved by genetic accommodation of endocrine pathways which control metamorphosis, thus showing how phenotypic plasticity within species can evolve into trait variation among species. (DW)

  • Breaking News! November 1, 2017: One of the most iconic salamanders, Jackson’s Climbing Salamander, has been rediscovered in the recently established Finca San Isidro Amphibian Reserve (also known as Yal Unin Yul Witz) on the northern slopes of the Sierra de los Cuchumatanes, Guatemala, very close to the original discovery site. A sub-adult found by reserve guard Ramos Leon is only the third specimen ever seen. The species had not be seen since September 1975, and was listed among the top 25 most wanted species in the world by Global Wildlife Conservation’s The Search for Lost Species. This event is a valuable reminder of the important contribution to wildlife preservation of focused habitat protection. Bolitoglossa jacksoni is a strictly arboreal salamander whose close relatives in the subgenus Bolitoglossa range from San Luis Potosi, Mexico, to central Panama. All are arboreal and lay eggs that hatch as miniatures of adults and have no aquatic larval stage. Hence, they typically are difficult to find.

  • October 30, 2017: Although many animals avoid toxic prey, some use the toxins of their prey to ward off predators. However, toxic animals risk self-poisoning unless they can resist their own toxins. Tarvin et al. (2017) found that in poison frogs the basis of self-resistance to the neurotoxin epibatidine is a single genetic change that evolved in three groups; nature hit upon the same solution repeatedly. This change occurs in the nicotinic acetylcholine receptor, the molecular target of epibatidine. It makes the receptor more resistant to epibatidine, but it inhibits normal function by decreasing sensitivity to acetylcholine. To cope with this acetylcholine issue, some poison frogs evolved additional mutations that compensate for the cost by modifying the molecule so that acetylcholine activation is normal, but the negative effect of epibatidine is still reduced. (DCC)

  • October 23, 2017: Parental care in frogs is a fascinating, yet understudied facet of amphibian behavioral ecology. This behavior is rare, in fact, only 10-20% of anurans. Delia et al. (2017) recently explored the functional dynamics, sex-role characteristics, and evolution of parental care in glass frogs (Family: Centrolenidae). Their integrative study of 40 species combined behavioral field observations, maternal commitment assays, disturbance trials, predation experiments, and comparative phylogenetic methods to both elucidate patterns of care, and analyze the evolution of sex-roles. Parental care was observed for all 40 species, including eight for which care has never been documented. The care-giving sex was variable across the family, and phylogenetic analyses suggested that rather than no care-to-male care transitions, male care evolved 2-3 times from female-only care. Moreover, they suggest that extended parental care past brooding was associated with male care state transitions. (JFrederick)

  • October 16, 2017: Ancestral salamanders likely had a biphasic life cycle. Hypothesizing that adaptations at one stage might limit adaptations at the other, Bonett and Blair (2017) studied rates of evolution of the basic body morphology of taxa with the ancestral biphasic cycle and those that are permanently aquatic and permanently terrestrial. Both had accelerated evolutionary rates relative to taxa that retain the ancestral life cycle, but rates were significantly higher in the aquatic as compared with the terrestrial taxa. This suggests that constraints on evolution can be stage-specific. Long-term shifts in life cycle complexity can have long lasting effects on phenotypic diversity in salamanders. (DW)

  • October 9, 2017: Sensory losses or reductions are frequently attributed to relaxed selection. However, frog species have lost tympanic middle ears many times, despite their use in acoustic communication and for hearing airborne sound. Womack et al. (2017) set out to determine whether pre-existing alternative sensory pathways enable frogs lacking tympanic middle ears (or ‘earless anurans’) to hear airborne sound as well as eared species or to better sense vibrations in the environment. They used auditory brainstem recordings to compare hearing and vibrational sensitivity among 10 species (six eared, four earless) within the Neotropical true toad family (Bufonidae). They found that species lacking middle ears are less sensitive to high frequency sounds; however, low frequency hearing and vibrational sensitivity are equivalent between eared and earless species. Furthermore, extratympanic hearing sensitivity varies among earless species, highlighting potential species differences in extratympanic hearing mechanisms. They discuss how sufficient extratympanic hearing and vibration sensitivity along with species-specific behaviors may allow earless lineages to detect conspecifics, predators, prey, and tolerate middle ear loss. (MWomack)

  • October 2, 2017: Net diversification rates (NDRs) are defined by speciation rates minus extinction rates through time. Species richness variability is owed to NDRs; however, the drivers of diversification rates themselves are poorly understood. Moen and Wiens (2017) investigated which ecological factors are best correlated with NDRs among frog families. They first compiled microhabitat data from IUCN and AmphibiaWeb with existing phylogenetic and climate data for ~3,300 sp. across 53 families. They then tested the relationships between NDRs and microhabitat, climate niche position, and climate niche change. Interestingly, they found that microhabitat explained the most of the variation in anuran NDRs with an emphasis on arboreality. This finding raises important considerations for our understanding frog diversification, namely the role of arboreality in: reproductive diversity among radiating lineages, expanding the vertical dimensionality of available habitats, and facilitating ecological opportunity through new adaptive zones. (JFrederick)

  • September 25, 2017: Hyla versicolor has long been known to use tree canopies. However, Laughlin et al. (2017) recently discovered that the treefrogs use natural habitats much higher than previously recorded, more than 12 meters above ground. The authors initially set up passive-infrared sensor camera traps to study white pine (Pinus strobus) canopy ecology but unexpectedly captured night images of H. versicolor at 18 meters high on four separate occasions over 14 months. The images of H. versicolor were always associated with southern flying squirrels (Glaucomys volans), which were more likely to be sensed by the cameras than the small ectothermic frogs. During that time, the researchers also directly observed another H. versicolor individual during a summer day at 20.5 meters. The researchers speculate that the frogs are utilizing cooler, wetter microhabitats in the mid-canopy that allow them to maintain these heights during the day and at night. These observations highlight the need for natural history information on H. versicolor and on the non-breeding habitats and behavior of amphibians in general. (AChang)

  • September 18, 2017: The region of the western Amazon and foothill of the Andes is home to the highest anuran biodiversity, and understanding how its communities are assembled sheds light on processes that maintain amphibian biodiversity. In a recent study, Jiménez Robles et al (2017) examined species richness, beta diversity, and reproductive traits of amphibians locally at a site in Ecuador, and regionally using >100 sites across the Amazon and Andean foothills. Whereas species turnover across habitats was the main predictor at local scales, showing the importance of preserving a diversity of habitat types, at regional scale, elevation emerged as the main predictor explaining changes in species richness, reproductive modes and biotic dissimilarities. (ACatenazzi)

  • September 11, 2017: The chytrid fungus, Batrachochytrium dendrobatidis (Bd), affects hundreds of amphibian species around the world, yet many hundreds of species become infected yet are not susceptible. Multiple genomic strains (some vary in virulence) of the pathogen have been identified but only from a few Bd samples, due to the fact that pure Bd cultures are difficult to obtain. A new study (Byrne et al 2017) developed a custom Bd genotyping assay capable of working on material from skin swabs (a common collection method for Bd surveillance). The assay has the power to accurately discriminate among the major Bd clades, and could greatly increase our ability to interpret disease dynamics of amphibians in the wild. (VV)

  • September 4, 2017: A question that has long interested evolutionists is whether stages in complex life cycles are coordinated during evolution, or do they evolve independently? Sherratt et al. (2017) studied larval and adult specimens of 166 of the 244 Australian frogs using multivariate morphometrics in a phylogenetically informed analysis to explore macroevolutionary patterns. They found that tadpoles and adults evolve independently. Tadpoles display extensive homoplasy and little phylogenetic signal, possibly because of the apparent ease in which microhabitat shifts of tadpoles occur during species formation, and because tadpole body form is linked to ecology. Based on patterns of lineage densities in morphospace, the authors that argue that morphological innovation is easier in adult frogs than in tadpoles. (DW)

  • August 28, 2017: AmphibiaWeb is pleased to announce new species accounts for Crocodile Newts Tylototriton and Echinotriton and true salamanders from northwestern Africa (Salamandra algira), prepared by Axel Hernandez. The newt accounts are derived from Axel's attractive and useful new book (available from Chimaira). The newt accounts are based on extensive field experience and the book is lavishly illustrated with Axel's photos. He also presents maps prepared under his direct supervision. The African salamander accounts include separate parts for the four distinctive, geographically separated subspecies. Together, there are 26 full new accounts. We thank Axel Hernandez for his contributions and continuing cooperation. (DW)

  • August 21, 2017: A frog so distinctive that it required a designation as a new family, the Nasikabatrachidae, is one of the great biodiversity discoveries of this century. Now a second species of this clade, restricted to the Western Ghats of peninsular India, has been described (Janani et al 2017 Alytes PDF). In the short time since the initial discovery, a number of new localities of the first species, Nasikabatrachus sahyadrensis, have been recorded, all from the western slopes of the Western Ghats. Nasikabatrachus bhupathi is well separated geographically from the other, on the eastern slopes, an area that is generally drier and has a different climate. The new species breeds during the northeast monsoon, whereas N. sahyadrensis experiences a more humid environment and breeds during the southwest monsoon. Specialized rheotropically adapted tadpoles utilize cascades during seasonal flows. These species have no close relatives in India; their remotely related sister taxon is the Sooglossidae, endemic to the Seychelles. This distribution is a possible outcome of the tectonic history of the Indian Ocean region. (DW)

  • August 14, 2017: Frog calls are typically only produced by males, with the females of some species occasionally responding. However, while studying Limnonectes palavanensis, Goyes Vallejos et al. (2017) found that advertisement calls were primarily produced by females. Males also had advertisement and courtship calls, but they only produced them sporadically. The authors also found that females aggregate and call around a single male in a lek-like formation in which the male chooses a female. Lastly, after laying eggs, females leave males to guard eggs and transport tadpoles. All of these behaviors together demonstrate the first known instance of a sex-role-reversal mating system in amphibians. (AChang)

  • August 7, 2017: In the late 1990s, researchers linked the emergence of the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), with declines and extinctions of amphibians. The fine scale movement of the pathogen, across hundreds of meters, has been described (Vredenburg et al. 2010), but the larger scale dispersal of the pathogen, over 100s to 1000s of kilometers, is not well understood. Two reports hypothesize birds as dispersers. Garmyn et al. (2012) tested 397 wild geese in Belgium and found that 15% of them had evidence of Bd on their feet. In lab experiments, they showed that Bd is attracted to and can grow on goose toe tissue. A more recent study (Burrowes and de la Riva 2017) sampled 48 preserved aquatic bird specimens collected in the Bolivian Andes, an area where Bd has caused mass declines, and found evidence of Bd on 42% of the specimens. Clearly bird dispersal of Bd is possible. The next steps require a better understanding of how long Bd zoospores survive on birds, making transmission possible. (VV)

  • July 31, 2017:

    George Bernard Rabb
    January 2, 1930 - July 26, 2017

    Amphibians lost their most stalwart advocate with the death of George Rabb, longtime director of the Brookfield Zoo, one-time President of the Species Survival Commission and tireless leader of conservation movements and activities throughout most of his long lifetime, including leading efforts at the IUCN. George worked in the background, constantly prodding others into action, raising funds for favored programs, and encouraging others whether in the field, lab, NGO, legislature or halls of Congress. He was present at the 1990 Irvine meeting, in which evidence of a worldwide amphibian decline was first formally presented. Working with David Wake and others, he founded the Taskforce on Declining Amphibian Populations. He worked steadily on behalf of its several successor organizations. As a student at U Michigan, George worked on lizards, frogs and salamanders. He named species currently known as Dendrotriton megarhinus, Chiropterotriton cracens, C. priscus, C. magnipes, Aquiloeurycea praecellens (all plethodontid salamanders), and the frog Plectrohyla pycnochila, all valid. Dendrotriton rabbi was named in his honor, as well as Ecnomiohyla rabborum (which honors him and his late wife Mary). Farewell, good and loyal friend.

  • July 24, 2017: A study by Burkart et al (2017) compared susceptibility of two species of Peruvian marsupial frogs to chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd), and found that Gastrotheca nebulanastes (or Kosñipata Marsupial Frog) is susceptible, whereas its congener, Gastrotheca excubitor (or Abra Acanacu Marsupial Frog), is resistant. The study compared the anti-Bd abilities of cutaneous defenses, including skin bacteria and skin peptides, between the two species and found that bacteria, but not peptides, differed between the two species in their ability to inhibit Bd growth. The results highlight the importance of anti-Bd skin bacteria in providing frog species with protection from Bd and may inform mitigation strategies for other wildlife diseases. (VV)

  • July 17, 2017: On May 12, 2017, Canada took an official stance to protect amphibian diversity in North America by amending their Wild Animal and Plant Trade Regulations to restrict all salamander imports for one year. This was done in an effort to prevent the spread of Batrachochytrium salamandrivorans (Bsal), a deadly fungal pathogen that, if introduced, could decimate native amphibian populations and threaten ecosystem health. This proactive approach follows recommendations from AmphibiaWeb researchers who identified high Bsal-risk areas in North America by integrating Bsal habitat suitability, host availability, and salamander trade data (Yap et al. 2015). Other scientists have called for preventive measures as well, including the Canadian Wildlife Health Cooperative (Stephen et al. 2015) and the United States Geological Survey (Richgels et al. 2016). The one-year moratorium buys time for researchers to learn more about Bsal and develop a long-term strategy to defend against disease spread. (TYap)

  • July 10, 2017: Frogs rebounded from the end-Cretaceous extinction, 66 million years ago, in spectacular fashion. While many frog lineages survived, three prospered. The ranoids, hyloids and microhylids, comprising about 88 percent of living species, explosively radiated, taking advantage of newly vacated ecological opportunities. These are phylogenetically deeply nested lineages that trace back to African roots, according to a study by Feng et al. (2017). The dating of the synchronous events is based on an analysis of sequences of 95 nuclear genes and 20 paleontological and geological calibration points and is an exact match with geological time estimates. The newly radiating lineages took advantage of the rapidly developing angiosperm-based forests. Arboreal and direct-developing taxa, in particular, thrived early and throughout subsequent times. (DW)

  • July 3, 2017: Understanding species thermal niche is critical to predicting how amphibians will respond to climate change. To characterize the thermal niche of European alpine newts (Ichthyosaura alpestris), Gvoždík and Kristin (2017) devised a suite of behavioral and physiological experiments. Using both thermal gradient tracks to calculate preferred temperatures and respirometry trials to monitor aerobic capacity, they tracked food digestion as a measure of thermal performance. Given knowledge of ectotherm physiology one would predict that satiated newts should optimize their aerobic capacity for digestion (i.e., select thermal habitats that maximize their ability to process food). However, the alpine newts in their experiments instead behaved more “economically”, preferring body temperatures that were lower than those required for maximum aerobic capacity. They demonstrate the importance of considering maintenance costs for understanding measures of maximum physiological performance. Here, alpine newts did indeed demonstrate thermoregulatory behavior that maximized their ability to process food, yet they did it relative to the lowest possible energy expense. (JFrederick)

  • June 26, 2017: Habitat loss may be the most important factor in the biodiversity crisis. Campos et al. (2017) focus attention on the amphibian fauna of the Atlantic Forest of Brazil and conduct an integrative analysis examining taxonomic, functional and phylogenetic diversity to generate a cost-effective conservation plan. The inclusion of cost effectiveness is novel and enables the establishment of new priorities for biodiversity assessment that will doubtless be of general utility. Their analysis highlights priorities (at three levels of urgency) for establishment of additional protected areas. They calculate land cost effectiveness per year for preservation, and propose that protected areas be increased in size by from 5% to 16%, depending on which priorities are selected. This is an innovative and progressive approach that merits careful study. (DW)

  • June 19, 2017: The Northern Red-legged Frog (Rana aurora) is of particular conservation concern in the Pacific Northwest, where their population has decreased in abundance and in site occupancy in recent years. Nelson et al. (2017), using passive acoustic monitoring devices, have shed light on this cryptically breeding ranid dispelling previous notions of their natural history. They found that red-legged frogs actually breed over the course of at least 32 days instead of a brief two week window as previously thought. Most interestingly, they report that underwater chorus length lasted nearly 8 hours on average, with a maximum chorus length of 14 hours over the course of a single day! Their acoustic analyses also showed calling effort was affected by temperature specifically reduced by cold snaps. This study demonstrates the importance of continued acoustic monitoring for sensitive species, especially when conservation strategies often rely on occupancy and detection surveys. (JFrederick)

  • June 12, 2017: Habitat alteration is a main driver of global amphibian declines, but why are some species more impacted than others? Nowakowski et al (2017) compiled published abundance data for species from natural and adjacent disturbed habitats on five continents and examined their life history traits, population trends according to IUCN, and other factors to identify the features responsible for differing species sensitivity to habitat modification. In analyzing 204 species, they found species with small ranges with terrestrial larvae or larvae developing in lotic habitats are most sensitive to local habitat degradation. This refines previous studies, which also have correlated the highly imperiled state of narrowly endemic species, with specific traits that can help focus conservation efforts globally. (MK)

  • June 5, 2017: North American newts, Notophthalmus, form a relatively young clade that appears to be experiencing a mini-adaptive radiation (DeLisle and Rowe 2017). Derived taxa are becoming more aquatic. Males are diverging from females as a result of disruptive selection related to competition for food. This increase in sexual dimorphism is manifest in feeding-related head morphology. The authors suggest that sexual antagonism and its resolution may accompany local adaptation, environmental change and adaptive radiation, in contrast to some theoretical work suggesting that evolution of sexual dimorphism might act as a constraint. (DW)

  • May 29, 2017: Often conservationists lack information critical to developing recovery strategies for endangered species. The Cape Platanna, Xenopus gilli, is restricted in distribution to a few sites in southwestern Cape, South Africa, always in sympatry with Xenopus laevis, an invasive species. Vogt et al. (2017 PeerJ) assessed niche differentiation at two sites. The diet of X. gilli is much more diverse than that of X. laevis. Both consume large numbers of tadpoles of different amphibian species (reaching as high as 45% of prey), including congeners, but X. laevis, which is about three times as common as its congener, also consumes adult X. gilli and is thus a direct predator as well as a dominant competitor. Furthermore, dietary overlap is greater between smaller members of each species. An effective conservation strategy for X. gilli is likely to require removal of X. laevis. (DW)

  • May 22, 2017: Do steep thermal gradients limit dispersal and promote species diversification? In his classic “mountains are higher in the tropics” hypothesis, Janzen proposed that dispersal across mountain passes should be more arduous for tropical organisms exposed to reduced temperature seasonality than for temperate organisms. Zuloaga and Kerr (2016) adapted this prediction and examined whether temperature overlap between sites located at both sides of mountains ranges was associated with differences in amphibian assemblages. Although sites with low thermal overlap were generally associated with high species turnover, particularly in the tropical Andes, the study also found low thermal overlap across mountains of North America around 60º N, where amphibian assemblages are much less diverse and species turnover is low. These findings are likely conservative, because dozens of new high-elevation tropical amphibians are described every year, reinforcing the study’s conclusion that additional factors, in addition to the strength of thermal barriers, must play important roles in amphibian diversification across mountain ranges. (ACatenazzi)

  • May 15, 2017: Resident microbial communities living on amphibian skin can have significant effects on host health, yet the basic ecology of the host-microbiome relationship of many amphibian taxa is poorly understood. Prado-Irwin et al (2017) used NextGeneration sequencing to characterize intraspecific variation in the skin microbiome of the salamander Ensatina eschscholtzii xanthoptica, a subspecies composed of four genetically distinct populations distributed throughout the San Francisco Bay Area and the Sierra Nevada mountains in California, USA. They found that salamanders from four geographically and genetically isolated populations harbor similar skin microbial communities, and that they were significantly different from those of the surrounding terrestrial environment. These results suggest that the relationship between E. e. xanthoptica salamanders and their resident skin microbiomes is conserved, possibly indicating a stable mutualism between the host and microbiome. (VV)

  • May 8, 2017: Many amphibian species that are phenotypically indistinguishable are genetically very distinct, leading to the recognition of "cryptic" species. The reverse case, in which interspecific variation in traits such as color is high, relative to genetic divergence, is less common. Tarvin et al. (2017), in a study of the poison frog group Epipedobates, found that among species that are otherwise easily distinguishable by calls and coloration, genetic divergence is only 2 to 3%. Moreover, this rapid divergence resulted in two independent origins of colorful aposematic species. Probably no other group of frogs shows so rapid an origin of the aposematic phenotype. (DC)

  • May 1, 2017: The genus Microhyla (family Microhylidae), consists of 40 known South and Southeast Asian species that reproduce in still waters. Only two species are known to exclusively breed in plants. One of those is Microhyla arboricola, which breeds in water-filled tree hollows and lays eggs above water collected in the hollows much like co-existing species in the Rhacophoridae family. Vassilieva et al (2017) further examined the unique biology of M. arboricola and found that the tadpoles were hatched with endogenous yolk supplies but switched to oophagy, or egg consuming, once the yolk ran out. Their mouth and body morphology is consistent with oophagy. This marks the first Microhyla species to display tree-breeding and oophagy. (AChang)

  • April 24, 2017: Bsal, the recently discovered fungal pathogen of amphibians, has proven to be highly virulent and has wiped out local populations of salamanders in northwestern Europe. Thanks to a new report by Stegen et al. (2017) we have a much better understanding of Bsal, and what has been learned brings no comfort. Pathogenicity and transmission were studied. They found no evidence of decreased virulence since discovery of Bsal, which is expected in host-pathogen interactions. Experiments to increase immunity of the salamanders failed. There is no evidence of immunity in populations studied. In nature, the fungus is able to survive for long periods in the form of thick-walled, water-resistant encysted spores, not previously reported in Bd or Bsal. These spores likely can survive sufficiently to travel on the feet of waterfowl and persist in the environment without hosts for some period. The combination of biological traits makes Bsal a truly formidable threat to salamanders. (DW)

  • April 17, 2017: Amphibians as ectotherms are limited by their surrounding temperatures, and since we are entering a period of rapidly changing global climate, it is imperative that we understand how they will react. In tropical montane regions, critical thermal limits are thought to be correlated with the elevational distribution, but von May et al. (2017) recently discovered that both tolerance to heat and cold vary substantially along a montane gradient in the Andes-Amazon region of Peru. Their study considered the temperatures of the microhabitats in which the frogs live, and found that lowland amphibians are more sensitive to increased temperatures than high-elevation species, because they live at ambient conditions that are closer to their critical thermal limits. (VV)

  • April 10, 2017: AmphibiaWeb and Map of Life have teamed up in an ambitious project called VertLife (NSF Grant 1441652) which aims to coordinate and compile comprehensive information on vertebrate distributions, life history traits and multi-loci molecular phylogenies. As part of our data partnership, we present the new Map of Life widget on each species page. Details of their spatial datasets are seen in a new tab called Map of Life, which includes point observations from GBIF, checklist inventories and expert range maps (e.g., Scaphiopus couchii). We still offer BerkeleyMapper views of VertNet data and range maps that come from either IUCN or AmphibiaWeb efforts. A plethora of spatial data is available that can help inform conservation decisions or highlight discrepancies worthwhile of study. As VertLife progresses, look for new features on AmphibiaWeb pages.

  • April 3, 2017: Frogs around the world are beloved for their striking colors and markings that can be involved in camouflage, warning predators, and attracting mates. Yet once the lights go out, our focus tends to shift to the noises they make and not what they look like. A new study by Taboada et al. (2017) finds that at least one frog, Hypsiboas punctatus, is naturally fluorescent. Compounds found in the lymph and skin glands fluoresce through the transparent skin making the frog standout in the dark. While known for just one species, this may be more widespread across frogs and yet another form of visual communication. (DB)

  • March 27, 2017: High elevation tropical environments are experiencing rapid change as a consequence of climate warming, and their glaciers are melting fast. The ongoing deglaciation is opening up new aquatic habitats for pond-breeding amphibians. Seimon et al. (2017) describe the vertical migration of Pleurodema marmoratum, Rhinella spinulosa and Telmatobius marmoratum to newly deglaciated ponds up to 5400 m in the Andean Cordillera de Vilcanota of Peru. Over the past decade, the newly established anuran populations have endured chytrid epizootics, changes in pond hydrology, and sharp reduction in the abundance of T. marmoratus. Despite these challenges, the three species continue to breed in this system of connected wetlands, and populations of T. marmoratus have recently recovered, possibly because individuals have acquired greater resistance to chytridiomycosis. (ACatenazzi)

  • March 20, 2017: The world’s amphibians have undergone a pandemic caused by the chytrid pathogen Batrachochytrium dendrobatidis (Bd), and the devastation is worse than any previous disease. In 2013, a new chytrid pathogen, Batrachochytrium salamandrivorans (Bsal), was identified infecting and killing fire salamanders (Salamandra salamandra) in Europe. Martel et al (2014) proposed that Bsal was introduced into Europe on Asian salamanders transported to Europe in the international pet trade. A new study by Laking et al. (2017) supports that hypothesis by discovering Bsal in wild salamanders in Vietnam. They report low level Bsal pathogen endemism (<3% prevalence) in 8 species of salamanders. They also report two key discoveries: Bsal and Bd co-existence within populations, and Bsal can occur in warmer than expected water bodies. (VV)

  • March 13, 2017: The recently emerged salamander-killing chytrid fungus, Batrachochytrium salamandrivorans (Bsal), threatens hundreds of species, yet is still largely unknown. Schmidt et al. (2017) used mathematical models to predict Bsal temporal and spatial dynamics. Using parameters associated with the fire salamander (Salamandra salamandra) and expert opinion, their model predicts Bsal outbreaks can occur at densities as low as one female per hectare, putting nearly all wild populations at risk. They also estimate that Bsal can move at a speed of 11.5 km/year. Since Bsal can lead to local extirpations in a relatively short time, the authors recommend that any effort to control an outbreak will likely be extremely difficult, and instead the focus should be on limiting pathogen spread and establishment among sites and populations. (Alan Chan-Alvarado)

  • March 6, 2017: A notable trend in the herpetological literature is the growing digital library of regional herpetofaunas. To this list, Kuzmin et al. (2017) have added "The Amphibians of Mongolia" (KMK Scientific Press), a distinctive contribution available gratis as a 304-page pdf on AmphibiaWeb's new page. The volume is in Russian and English, and co-authored by Mongolian and Russian biologists. Only five frog and one salamander species are known in the State of Mongolia; the volume presents extensive information in sections on their population declines, conservation, ecology, and biogeography. The species accounts are thorough, with full synonymies, species descriptions, photos of tadpoles, and maps with georeferenced locality data. The book ends with a variety of color plates, picturing not only each species and their habitats, but also herpetologically themed petroglyphs, sculptures, and postage stamps. (DC)

  • February 27, 2017: The Night Frogs, Nyctibatrachidae, is a small, ranoid family endemic to the Western Ghats in peninsular India. Until now, the moderate-to large-sized species (up to more than 80 mm body size) have been primarily stream-dwelling. Research in the Western Ghats continues to be productive, with new species from several families being announced at regular intervals, and it is widely recognized as an important biodiversity hotspot. Garg et al. (2017) discovered seven new nyctibatrachids, but what is special about this find is the first miniaturized species in the family. Four of these new species, roughly 12 - 15 mm body size, were found in damp forest floor leaf litter and marsh vegetation. Apparently all have a tadpole stage. They have been overlooked in the past because of the small size, insect-like call, secretive habits and different habitat preferences, and they are locally abundant. Nevertheless, these habitats are subject to strong anthropogenic influences. The authors estimate that about one-third of nyctibatrachids are threatened with imminent extinction. (DW)

  • February 20, 2017: What happens when diverging subpopulations of more brightly colored members come into contact with less colorful ones? If preference is driven by either sexual selection, or natural selection, or both, we expect to see the two populations merge. Segami Marzal et al. (2017) ask whether an increased risk of predation acting directly on female preferences could counter this tendency, enhancing the probability of population divergence in a poison frog (Oophaga pumilio) where populations of aposematic (bright) and cryptic (dull) morphs come into contact in Bocas del Toro Archipelago, Panama. Using photos of the frogs, they trained chickens to peck at cryptic frogs for a reward. Their subsequent experiments showed that cryptic frog morphs were more likely to be discovered and pecked when they occurred near a brightly colored, aposematic morph. Thus, females of a cryptic morph might suffer a higher risk of attack when approaching a brightly colored male; this could directly select against female preferences for such males and hence reduce interbreeding between morphs, ultimately enhancing the probability of population divergence and speciation. (Kyle Summers)

  • February 13, 2017: Things are looking up for the Titicaca Water frog, Telmatobius culeus, also known as the “scrotum frog.” In January 2017, Peruvian President Pedro Pablo Kuczynski announced that the government will build ten water treatment plants around Lake Titicaca, the largest freshwater lake in South America. For decades, the lake has experienced high levels of water contamination resulting from mining activities, agricultural runoff, and raw sewage flowing into the lake—threatening local wildlife and people. Categorized as Critically Endangered by the IUCN Red List of Threatened Species, T. culeus is an iconic species because of remarkable adaptations to aquatic life at high elevation. The species was recently included in Appendix I of CITES, the Convention of International Trade in Endangered Species of Wild Fauna and Flora, in a measure to curtail its illegal collection and trade. News about construction of water treatment plants was equally well received by locals and the conservation community, especially after massive die-offs of the frog were reported from various sites around the lake. (Rudi von May)

  • February 6, 2017: Many species of Dusky Salamanders (Desmognathus) co-occur in southeastern United States. The greatest levels co-occurrence are at mid-elevations, where as many as 6 species are found. Are species richness patterns the result of ecological limitations or evolutionary diversification (speciation/extinction balance) of taxa displaying niche conservation? Camp et al. (2017) hypothesize that species are physiologically restricted to mid-elevations. They use niche-modeling approaches to test the hypothesis, concluding that species richness is not limited by physiological constraints. While important questions remain, the authors suggest that climatic factors affect habitat availability and, possibly, energy input. Biotic interactions among species may also be significant. (DW)

  • January 30, 2017: The tropical leaf-litter frog, Lithodytes lineatus, sports impressive yellow stripes along its back and typically lives in the nests of leaf-cutter ants (genus Atta), yet does not appear to suffer attacks from the ants, known to be highly aggressive towards nest intruders. De Lima Barros et al. (2016) tested the hypothesis that the frogs use chemical mimicry by producing or acquiring a coating of chemicals on their skin that deceives the ants into perceiving them as nest members rather than intruders. They tested individual L. lineatus against four similar species of frogs by confining them with leaf-cutter ants, and found that while all the other species were attacked, L. lineatus individuals were not and made no attempt to escape the ants. The researchers then prepared a skin extract from L. lineatus used to coat 10 individuals of another species (10 others were coated with purified water as a control). In contrast to the controls, the frogs coated with L. lineatus skin extract were not attacked by the ants. This provides experimental evidence that chemicals on the skin of L. lineatus provide an effective form of mimicry. (Kyle Summers)

  • January 23, 2017: Chytrid fungal pathogen NOT found in freshwater prawn: A correction- In August 2016 we highlighted a peer-reviewed study reporting Bd infection in a freshwater prawn (Paulraj et al. 2016). This news was unusual and exciting because little is known about the occurrence and importance of non-amphibian hosts for Bd. However, Pessier et al (2016) conclude that the supporting data and photomicrographs do not convincingly demonstrate the presence of Bd in the tissues of the affected prawns. They point out when putative hosts are identified, it is critical to provide adequate morphologic, molecular, and culture-based evidence. Molecular approaches (PCR) alone are inadequate because they cannot distinguish between the incidental environmental presence of Bd and true infection with replication of the fungus in host tissues. The identification of non-amphibian hosts for Bd is an important area of ongoing investigation into disease-related causes of global amphibian population declines. (VV)

  • January 15, 2017: Giant salamanders (Andrias in east Asia, Cryptobranchus in east North America) are remnants of an ancient lineage. Thanks to new field studies of the Japanese species (A. japonicus), we now know that males provide parental care, and for a very long period of time. Males actively seek burrows in stream banks that might serve as sites for mating and nesting. Females enter the burrow, occupied by a "den master" male and mating and external fertilization of the eggs takes place. The den master then provides parental care (tail fanning, agitation of eggs, and hygienic filial cannibalism of unfertilized eggs, or dead or dying embryos and larvae and other specialized behaviors) (Takahashi et al. 2016). Such behavior occurs over a long time period, up to seven months. The study adds substantial new information concerning egg deposition and parental care in nature, and will be critical for attempts to improve habitat and other recovery attempts for these amazing animals. (DW)

  • January 9, 2017: Throughout much of the Pacific Coast and Sierra Nevada drainages, the once abundant Foothill Yellow-legged frog (Rana boylii) has been disappearing, mainly due to habitat destruction, water diversion and pollution. In 2005, only 30 California sites had populations of 20 or more adults, including in the heart of their range in California’s north coast where the frogs have lost a quarter of their historic sites. On December 14, 2016, the Center for Biological Diversity (CBD) formally petitioned the US Fish And Wildlife Service to list the Foothill Yellow-legged frog as a threatened species under the California Endangered Species Act. This joins the the CBD’s 2012 petition for federal listing under the Endangered Species Act. Hopefully the state can act to protect this frog faster than the federal officials, which is expected to make a decision in 2020, none too soon for a disappearing species. (MK)

  • January 2, 2017: Happy New Year’s! In 2016, AmphibiaWeb recorded 107 new species, the fewest since we began keeping count in 2004. There were several revalidated taxa, raised from synonymy or uncertainty, giving a current total of 7,614 recognized amphibian species. The new taxa are from 20 families and 24 countries, so discoveries continue to be widespread and diverse. No new caecilians were described, but 11 salamanders (2 families) are new including the beautiful Aura's Golden Salamander. The greatest number of new species are in the Strabomantidae (22) and Microhylidae (17). Brazil (14) had the largest number of new species, followed by Papua New Guinea (13), India (11), and Ecuador (10). 10 were from Mesoamerica but none from the United States. Only 2 were reported from Africa, 2 from Madagascar, 2 from Australia and none from Europe. East Asia plus South Asia accounted for 31.

  • 2016

    back to News by Year
  • December 19, 2016: The earliest anuran with a nearly complete skeleton is Triadobatrachus massinoti from the Triassic of Madagascar. A new study (Lires et al. 2016) focuses on its limbs and those of a selection of modern frogs, salamanders and lizards. Previous hypotheses have interpreted the shortened but still somewhat elongated trunk, short tail, anuran-like but short pelvic girdle and somewhat elongated limbs as indications that hopping and jumping, along with salamander-like crawling, were important forms of locomotion in this early frog relative. The new research used multivariate morphometrical analyses of limbs, from which the authors argue that Triadobatrachus moved mainly by body undulations accompanied by asynchronous movements of the limbs. Furthermore, they argue that leaping or jumping was not possible, and that the anuran-like morphological features may not have evolved in a concerted fashion leading directly to synchronous limb movements and jumping. A provocative argument that these features are exaptations for jumping, co-opted during anuran evolution, needs further development. This isolated fossil will continue to tantalize researchers; more fossils are badly needed. (DW)

  • December 12, 2016: Costa Rica has the highest density of amphibians among all the countries in the world (4.05 species per 1000 km2; comparable figures are 2.9 for Panama, 1.9 for Ecuador). A new field guide by Twan Leenders (Cornell U Press 2016) reports 204 native species (with one more salamander published since the book appeared) an increase of 27 species since Savage’s 2002 book (The Amphibians and Reptiles of Costa Rica, U Chicago Press). There are now 147 (plus 3 introduced) frogs, 53 salamanders and 7 caecilians. Only Guatemala (85), Mexico (143) and USA (190) have more salamanders, but many countries (led by Brazil with 992) have more frogs. (DW)

  • December 5, 2016: The amphibian pet trade is known as a potential pathway for the global spread of amphibian pathogens, but few studies have looked at how pathogens in amphibians could spread to other species. A new study by Ip et al (2016) screened an imported shipment of Chinese Fire Belly newts (Cynops orientalis) and discovered they were infected with a rhabdovirus pathogen of freshwater fish, listed as notifiable to the Office International des Epizooties (OIE). This discovery reveals a novel route for potential spillover of this economically important pathogen as rhabdovirus has not previously been documented in amphibians and provides new evidence of the risks of live animal trade to wildlife. (VV)

  • November 28, 2016: Minute salamanders (Plethodontidae: Thorius) were once very common in montane habitats bordering the eastern and southern margins of the Mexican Plateau, where they have experienced an adaptive radiation in miniature. Molecular data have proven to be essential for sorting specimens into species, which are then discerned to differ in morphology, ecology, elevational distribution, etc. Species detection is an ongoing activity, made difficult by the increasing rarity of these tiny animals. A new paper (Parra-Olea et al. 2016) revises the taxonomy of the southern and easternmost members of the genus in Oaxaca, Mexico, redescribing two species while describing and naming three others. The new species all are considered to be critically endangered, and the entire genus appears to be on the brink of extinction from as yet undetermined causes. (DW)

  • November 21, 2016: Despite the genomic revolution, the first complete genome of a frog, Xenopus tropicalis, was sequenced only in 2010. Session et al. (2016) have sequenced the genome of another species, Xenopus laevis. Because X. tropicalis is diploid and the X. laevis is tetraploid, important inferences can be made about genome evolution. Based on analysis of the rate of synonymous mutations in protein-coding genes, they estimated that the two species diverged from each other about 48 mya, a date is remarkably close to the estimate based on phylogenetic analysis of fossils, morphology, and other genomic sequences. They also calculated that the lineage of tetraploid Xenopus species originated 17–18 mya from two now extinct diploid ancestors. (DC)

  • November 14, 2016: Using citizen science data from the Frog Mortality Project (1992-2013), which tracked reports of mass frog die-offs in the UK, and spatio-temporal models to reconstruct the spread of Ranavirus, Price et al (2016) tested three hypotheses for the increase in disease reportings of this emerging infectious disease. First that outbreaks were reported more frequently; second, that climate change had altered the host-pathogen relationship; lastly, that the pathogen was spread to novel places. Their results suggest that both amphibian movement and human activity contributed to the spread of disease. Further, phylogenetic analysis of Ranavirus point to at least two separate incursions to the UK. Human-mediated spread is both a cause for alarm and an opportunity to alter behaviour and hopefully arrest disease spread. (MK)

  • November 7, 2016: Maciel et al. (2016) analyze relationships of the semiaquatic and aquatic South American caecilians (Typhlonectidae), including all five genera. Their integrated analysis of molecular and morphological data (including new characters) finds that while Potamotyphlus and the lungless Atretochoana share several derived characters, Potamotyphlus is the sister taxon of Typhlonectes, not of Atretochoana. Accordingly, pulmonary reduction occurred convergently in Atretochoana and Potamotyphlus. This careful and thorough study opens new avenues of research questions about the evolutionary dynamics of the clade, such as examination of the ecology and development of reduced pulmonary function. (MH Wake)

  • October 31, 2016: The Strawberry Poison Frog (Oophaga pumilio) of Central America has undergone a dramatic radiation in color pattern across allopatric populations living on different Panamanian islands of the Bocas del Toro archipelago and the nearby mainland. Previous research had found that a number of the island populations showed biased mating preferences toward the color pattern of their own population, suggesting that sexual selection is driving divergence, reproductive isolation and ultimately speciation. In a transition zone between red and blue frogs, Yang et al (2016) carried out a key test of whether mating preferences are likely drivers of reproductive isolation and speciation by comparing preferences of a contact zone population where individuals encounter pure morphs (red and blue) and intermediates. As expected, they found that pure morphs from either side of the contact zone displayed a significant preference for their own color pattern morph (e.g., blue females preferred blue males). Yet, intriguingly, they found that frogs from the contact zone showed a strong preference for the red morph, even if they were blue. This contradicts a key prediction that sexual selection is driving reproductive isolation and speciation in this system, and opens up questions of what is preventing the blue morph from being swamped by genes for the red morph, which is the common mainland pattern of O. pumilio. (Kyle Summers)

  • October 24, 2016: Major habitat restoration moves ahead for two endangered montane frogs in California. After years of review and planning, the National Park Service (USA) is officially moving forward with major plans to restore high elevation aquatic ecosystems in the Sequoia and Kings Canyon National Parks in the Sierra Nevada of California. These actions will help recover two endangered montane frogs, the Sierra Nevada yellow-legged frog (Rana sierrae) and the Sierra Madre or Southern Mountain yellow-legged frog (Rana muscosa). These significant conservation actions, based in part on results from a 2004 field experiment (Vredenburg 2004) showing rapid recovery of endangered frogs after removal of introduced non-native fish (trout) from habitats, will help the frogs as they face new threats such as disease, drought and climate change. (VV)

  • October 17, 2016: Nearly all of the reports on global patterns of amphibian extinction and decline have been bad news, with hundreds of species lost and thousands in jeopardy. A new report in PNAS (Knapp et al 2016) shows a regional pattern of recovery across hundreds of populations in Yosemite National Park for a charismatic species, the Sierra Nevada Yellow-legged frog. The study is based on >7,000 frog surveys over a 20-year period and showed recovery despite ongoing stressors such as disease and introduced predatory fish. Results from a laboratory experiment indicate that these increases may be in part because of reduced frog susceptibility to chytridiomycosis, but the cessation of fish stocking also contributed to the recovery. Continuing studies will determine if local extinction sites become repopulated. (VV)

  • October 10, 2016: Despite knowing that the pathogen Batrachochytrium dendrobatidis (Bd) is an important factor in global amphibian declines, much of its ecology and life cycle is unknown. To further studies in the lab, Betancourt-Roman et al (2016) examined the role of invertebrate hosts as potential infection models to study virulence and pathogenicity of Bd. Contrary to previous studies and suggestions, the electric blue crayfish and nematode were not negatively affected despite heavier inoculum loads and a larger variety of pathogen genotypes tested than in previous studies. In fact, infected crayfish generally gained weight and suffered no fatalities. This study provokes more questions on the ecology of Bd with respect to micro- and macro-invertebrates. (MK)

  • October 3, 2016: Asexual, parthenogenetic animals are rare, and although they have a short-term selective advantage, they are considered evolutionary dead-ends that should not persist in the long-term. Despite this theory, an asexual lineage of mole salamanders (Ambystoma sp.) has been estimated to have existed for ~5 million years. Cryptic sex has been proposed as an explanation for why this lineage has persisted. Gibbs and Denton (2016) tested this hypothesis using genome-specific microsatellite DNA markers to compare gene flow to asexual females from either sympatric or allopatric males. They determined that relatively high rates of unidirectional gene flow was occurring from sympatric sexual males to asexual females. Their results also indicate the unisexual lineage has a strong selective advantage that prevents the partial genome exchange from sexual males from overwhelming the lineage and causing its extinction. (AChang)

  • September 26, 2016: Acoustic signals of frogs have been extensively studied, but much less is understood about their visual signals. In an extensive review, Rojas (2016) draws attention to polymorphism in color pattern within populations of a species. Although intra-populational polymorphism in pattern is known in several cryptic species, aposematic species are not expected to be polymorphic because this would reduce the efficiency of predator learning. Nonetheless, some species are. Although there is evidence that sexual selection may play a role, other explanations, such as spatiotemporal variation in selection, are possible. These are likely to be fruitful new avenues of research on the origin and maintenance of color pattern. (DC)

  • September 19, 2016: Has horizontal gene transfer influenced the pathogenicity of the chytrid pathogen? After the chytrid genome sequence was released, Sun et al. (2011) used phylogenetic methods to identify genes that had been acquired by the fungus through horizontal gene transfer (HGT). They found various genes in the chytrid genome acquired from other organisms, including those known as virulence effectors. In particular, a large CRN (“crinkler protein”) gene family was transferred to the chytrid from oomycetes, and another family encoding serine peptidases from bacteria. Together, the sets of genes are known to be involved in pathogenicity in multiple contexts, including infection of keratinized tissue (a key feature of chytrid infection) in other pathogens and both gene families are expressed during the infection of host tissues by the chytrid. Further, research on CRN13 gene effector product in plant cells show that they target nuclear DNA, causing cell damage and death, and in Xenopus embryos, cause abnormal cell development (Ramirez-Garces et al. 2016). A new study (Sun et al. 2016) shows further evidence for the horizontal gene transfer of pathogenic genes into the chytrid. In a broad survey, the authors identified 23 gene families acquired by HGT, including five gene families likely involved in infection and pathogenicity. Hence, accumulating evidence points to genes acquired by the chytrid through HGT may have contributed to the devastating virulence of this fungal pathogen. (Kyle Summers)

  • September 12, 2016: In a “Biological Conservation” article, Rowley et al (2016) called for all Southeast Asian newt species to be listed by CITES. This recommendation is based on known threats and documented population declines caused by the amphibian pet trade and findings by the authors that the majority of the pet trade was trafficking wild-caught animals that ultimately ended in Europe, North America, and other parts of Asia. More specifically, between 2005 - 2014, over 7,500 individual newts were imported to the US, and between 2011 - 2013, 718 individuals were imported to the EU. However, these numbers are underestimates as much of the amphibian pet trade is undocumented. CITES listings of Appendix I, II, or III (when species are endemic to a single country) are honored by all the countries the newts are known to be imported into and would allow better monitoring and regulation of each species. (AChang)

  • September 5, 2016: Max Sparreboom | In Memoriam: January 18, 1951 - August 30, 2016
    AmphibiaWeb regrets the passing of Max Sparreboom at the age of 65. Max was a distinguished scholar of Asian languages and former Dean of the Faculty of History and Arts of Rotterdam Erasmus University, and Director of the Praemium Erasmianum Foundation, which awards the Erasmus Prize. He was well-known to the international herpetological community for his comparative ethological studies of salamanders and especially for his masterful and comprehensive book The Salamanders of the Old World (2014). At the time of his death, Max was a Research Associate of Naturalis Biodiversity Center in Leiden, The Netherlands. Max contributed 76 photos to AmphibiaWeb. He will be deeply missed by colleagues and friends. (DW)

  • August 29, 2016: Factors responsible for the high species richness of tropical amphibians remain elusive. A new study (Vijayakumar et al. 2016) of the Shrub Frogs, Raorchestes, the largest vertebrate radiation in Peninsular India, tests alternative hypotheses using a well-resolved, dated phylogeny with information on geological and geographic events, glaciation and climatic history, and ecology (e.g., ecological gradients). All of these factors have played roles in clade diversification, but they vary across space in their effects and have acted at different times during the last (at least) 30 million years. The study highlights the significance of a major gap (Palghat Gap) in the Western Ghats system, and the importance of the geography of the different massifs making up the system. Although most species formation has been allopatric in nature, high elevation massifs have acted as centers of diversification, with parapatry being important, whereas low and mid-elevation portions of the southern Western Ghats act as biodiversity "museums". (DW)

  • August 22, 2016: A major concern with amphibian pathogens is their introduction into new regions. A new study by Garcia-Diaz et al (2016) used two statistical models, each under two different scenarios, to investigate the effectiveness of border and post-border biosurveillance and biosecurity in reducing the likelihood of introductions of ranaviruses via non-native amphibian species into Australia. Biosecurity is thought to be relatively effective in Australia. The total number of amphibian stowaways increased with high transport pressure between 2004 and 2012, illustrating the increased need for biosecurity screening. Border and post-border biosecurity activities led to a reduction in the risk of introduction of alien ranaviruses into Australia. Although far from perfect, biosecurity screening should be emphasized as a critical factor in limiting the diffusion of amphibian pathogens. (DW)

  • August 15, 2016: A new study by Paulraj et al. (2016) reports the discovery of the chytrid pathogen Batrachochytrium dendrobatidis (Bd) in 15 shrimp farms in Tamil Nadu, India, where it infects the freshwater prawn Macrobrachium rosenbergii, a major food source in India. The pathogen is reported to be the responsible agent in several major pandemics that have strongly affected the prawn fishery. While Bd has been reported in some crustaceans before, this is the most extensive study to date and shows that Bd may have diverse reservoirs in different regions and ecological communities. (DW)

  • August 8, 2016: Studying disease has been important in amphibian decline research, not only informing amphibian conservation but also helping build the foundations of disease ecology. A new paper by Hite et al. (2016) examined habitat–disease links through direct effects on parasites (the chytrid fungus) and indirect effects on parasite predators (zooplankton), and the combined effects of host diversity and key life stages of hosts. A field experiment in alpine ponds showed that ultraviolet radiation (UVR) killed the free-living infectious stage of the fungus, but in permanent ponds had higher infection prevalence. Two indirect effects worked together to counteract parasite losses from UVR: (i) UVR reduced the density of parasite predators and (ii) permanent sites fostered multi-season host larvae that fueled parasite production, thus sites with higher diversity of host species had lower prevalence of infection. While habitat structure explained considerable variation in infection prevalence through two indirect pathways, it could not account for everything. This study demonstrates the importance of creating mechanistic, food web-based links between multiple habitat dimensions and disease. (VV)

  • August 1, 2016: What are the highest temperatures that frogs can tolerate? Kuchinoshima Island is a tiny (13.33 km2) volcanic island in the Tokara group, just south of the main islands of Japan. It harbors a population of the Ryukyu Kajika Frog Buergeria japonica, which has limited breeding sites. Tadpoles on this island were found in hot springs, and a new study (Komaki et al., Amphibia-Reptilia 2016) reports on the thermal tolerance of the species. The highest temperature of a pool occupied by tadpoles was 46.1 °C. Experiments show that this is very close to the critical thermal maximum of the species. Other frogs are known to inhabit hot springs but this is the highest temperature recorded in nature. (DW)

  • July 25, 2016: The Cajun Chorus Frog, Pseudacris fouquettei, the most recently named frog in the United States, hybridizes with the Southern Chorus Frog, Pseudacris nigrita. A hybrid zone exists across the lower Pearl River at the Louisiana-Mississippi border. Since the zone was first characterized in 1980, its center has remained stable. However, it has widened substantially (Engebretsen et al 2016). This indicates that the region is not a tension zone, with strong selection against hybrids, but that hybrids are relatively fit. Hybrids are more common than in the past, and more widespread. The sister taxa appear to be gradually merging. Monitoring the zone should be a research priority for future workers. (DW)

  • July 18, 2016: The reproductive modes of anurans are the most diverse of terrestrial vertebrates, and a major challenge is identifying selective factors that promote the evolution or retention of reproductive modes across clades. Portik and Blackburn (2016) examined these topics in a comparative phylogenetic framework using Afrobatrachian frogs, an ecologically and reproductively diverse clade, and more than half of the total frog diversity found in Africa (~400 species). In this group, they inferred direct development has evolved twice independently from terrestrialized reproductive modes involving subterranean or terrestrial oviposition, supporting evolution through intermediate stages. They also detected associations between specific ecomorphologies and oviposition sites, and demonstrated arboreal species exhibit an overall shift towards using lentic water systems for breeding. These results indicate that changes in microhabitat use associated with ecomorphology, which allow access to novel sites for reproductive behavior, oviposition, or larval development, also promote reproductive mode diversity in anurans. (Daniel Portik)

  • July 11, 2016: Indian biodiversity is concentrated in three major, disjointed, wet-zones: North-East India and the Western and Eastern Ghats of peninsular India. There is little overlap in the biota found in each of these zones, which begs the question of what the biogeographic origins for the biota are in each zone and how the biota are related to each other. Gower et al. 2016 explored these questions using the genus Gegeneophis, which occurs in both the biologically well-explored Western Ghats and the less explored Eastern Ghats, to build a molecular clock. Although the mechanism is still unclear, they found that the only known Eastern Ghats caecilian, Gegeneophis orientalis, split from all Western Ghats at least 35 mya during the late Eocene or early Oligocene. The authors argue for increased exploration of the Eastern Ghats as the region may have provided a moist refugium for a sustained amount of time during the mid-Cenozoic era and thus may have many undescribed, low-vagility, endemic, taxa. (AChang)

  • July 4, 2016: Arboreal embryos of Red-eyed Treefrogs (Agalycnis callidryas) hatch prematurely and very rapidly (6.5 - 49 seconds) in order to escape from snake attacks. Cohen et al (2016) studied the three stages of hatching (pre-rupture shaking and gaping, vitelline membrane rupture near the snout, and muscular thrashing to escape). Electron microscopy revealed hatching glands densely clustered on the snout that are filled with vesicles that release their contents rapidly at hatching. Hatching in most anurans is relatively slow. Characterization of the postulated hatching enzyme remains to be accomplished. Comparative studies of the glands should reveal differences among taxa to determine whether this or other novel mechanisms are employed. (DW)

  • June 27, 2016: To gain a better understanding of the African genus Amietia, which is currently composed of 16 cryptic species, Larson et al. (2016) recently analyzed the genus using newly collected samples from The Albertine Rift, which is home to five Amietia species, and published species sequences. They showed that Amietia is monophyletic, diverged in the late-Oligocene to early-Miocene (17.44–31.97 mya), and contains more species than previously thought. Amongst the 79 samples collected, a known vertebrate biodiversity hotspot, they found six undescribed species. All of the new species were found in unprotected land and all the Amietia species in the Rift are currently threatened by political instability, habitat loss, and chytridiomycosis. Although political instability makes it difficult for researchers to gain access to areas where these undescribed species exist, the researchers are optimistic that more undescribed species can be found there and urge future surveys and conservation efforts in the area. (AChang)

  • June 20,2016: A new study (Willaert et al. 2016) presents the first details of the reproductive behavior of frogs of the Indian endemic family Nyctibatrachidae. There are several surprises. The subject of the study, Nyctibatrachus humayuni, is a stream-breeder. Both males and females call, although the latter is rare and of unclear function. Males call from territories that may be partly submerged, but usually are on rocks, vegetation and fallen trees bordering or overhanging the stream; territories were observed up to 4 m above water. A female approaches a male, who mounts the female without using a grasping amplexus, instead using the hands to hold onto vegetation, thus supporting the pair. This is termed a "dorsal straddle". This loose embrace is short in duration. Immediately after the male dismounts, the female lays the full clutch in a few seconds, without any physical contact with the male. The eggs when collected immediately are already fertilized, leading to the hypothesis that the male spreads sperm over the surface of the female's back and legs, enabling fertilization as the eggs are laid. (DW)

  • June 13, 2016: The hylid frog fauna in parts of South America is sufficiently rich to permit recognition of different locomotor modes and habitats, suggesting ecomorphs. In an impressive new paper, Soliz and Ponssa (2016) studied 14 hylids that differed in locomotion and habitat. Biomechanical analysis focused on relationships between ligaments and sesamoid skeletal elements. A special role for heterochrony is suggested. They tested hypotheses of adaptation versus common ancestry using a phylogenetic analysis, and present evidence for both effects. This detailed, well-illustrated study will likely prove to have heuristic value for other taxa and regions. (DW)

  • June 6, 2016: Eastern North American woodlands have been invaded by Asian earthworms, potent ecosystem engineers. They accelerate leaf litter decomposition and nutrient release, consume detritus, and alter edaphic properties, all potentially significant to co-occurring salamanders. An experimental lab and field study (Ziemba et al. 2016) examined the impact of invading earthworms on Eastern Red-backed Salamander, Plethodon cinereus, in Ohio. Salamanders use lower quality microhabitat and consume fewer prey in the presence of earthworms, and behave aggressively toward earthworms. Earthworms and salamanders share cover objects less often than random expectations. Earthworm abundance was negatively associated with abundance of some salamander classes. Loss of cover and physical exclusion of salamanders likely hinders salamander performance, Thus, a scenario following earthworm invasion is reduced recruitment and abundance. While P. cinereus is widespread and abundant and is not under immediate threat, related species with restricted geographic ranges might well face great threat from future earthworm invasion of their isolated ecosystems. (DW)

  • May 30, 2016: Over 25 years ago when researchers first began tackling the problem of global amphibian declines, studies began by focusing on single factor hypotheses that might explain global patterns. Since then, many studies have proposed that multiple factors may be responsible. The USGS Amphibian Decline Working Group (Grant et al 2016) studied 61 documented areas in North America covering 83 species to test the impact of four hypothesized large-scale factors: human disturbance, chytridiomycosis, pesticide effects, and climate change, especially in rainfall. They found that each stressor was regionally variable but did not explain declines at a continental scale. They conclude that the best conservation strategy must emphasize local solutions rather than a large-scale comprehensive approach. (VV, MK)

  • May 23, 2016: How long do salamanders live? Staub (2016) reviews evidence for salamanders of the family Plethodontidae, and concludes that these generally small animals can attain relatively great age. The most direct evidence is from captive animals, and members of Plethodon, Aneides and Phaeognathus, among others, have attained ages in excess of 30 years (the individual in the photograph was collected as an adult in April 1985, and is still apparently in robust health). In a separate field study (Staub 2016a), Aneides flavipunctatus longevity was estimated to be on the order of 18 or 25 years, using different methods. Other field estimates also show long lives, as great as 32 years. Methods tend to be conservative, and some individuals might be substantially older. (DW)

  • May 16, 2016: The Paradoxical Frogs, genus Pseudis, are so-named because the tadpoles of the first-named species, P. paradoxa, are enormous, larger than the adults. The tadpoles have bodies that are ovoid in general shape and very large; in lateral view, tadpoles are triangular in outline and higher than wide, with well-developed tail musculature. A new study focused on P. fusca and P. tocantins (Santana et al. 2016) demonstrates that, like other species of Pseudis studied so far, they have typical tadpoles, although each of the six species studied has distinctive features associated with the oral disc. Despite their extraordinary tadpoles, Pseudis is in the family Hylidae. (DW)

  • May 7, 2016: Saturday, May 7, has been declared Salamander Saturday, a day to promote international awareness of salamanders and to promote their conservation. The Foundation for the Conservation of Salamanders has developed activities for this day throughout the US and in Canada. We celebrate salamanders everyday. Learn more about salamanders on AmphibiaWeb. See some Amazing Salamander profiles from our Amazing Amphibian archives.

  • May 2, 2016: Duellman, Marion and Hedges (2016) offer an alternative taxonomy for hylid frogs. No new data are presented and the authors’ goal, to use taxonomy to reflect biogeographic divergence, can often be accomplished by use of subgenera. AmphibiaWeb will move methodically to accept or reject specific features of this taxonomy, which is purely subjective and not required by any cladistic or nomenclatural considerations. We invite your views via Twitter or Facebook in the coming weeks. Examples of the proposed taxonomy: Hylidae is split into three families; Hyla is subdivided, with the effect that it no longer occurs in the New World; western tree frogs are placed in a newly genus; new genera are established for some tropical clades.

  • April 25, 2016: Besides making its hosts sick, a pathogen may also alter the host's behavior. An and Waldman (2016) found that Japanese Tree Frogs (Hyla japonica) with natural infections of Batrachochytrium dendrobatidis called longer and made more rapid calls than did uninfected males. This may have two effects, possibly interrelated. Because female frogs are known to be generally attracted to males that call longer and faster, pathogen transmission might be enhanced. Alternatively, the altered calls might result from selection on males for early reproductive success in anticipation of a premature death. However, it is unknown whether Japanese tree frog females prefer infected males. (DC)

  • April 18, 2016: Signaling between parents and offspring is a topic of interest in animal behavior and evolution, mostly in birds and mammals. A common question is whether offspring begging directed at parents represents an “honest signal” of need (hunger), or a signal of quality (with larger, higher quality offspring able to signal more strongly). Yoshioka, Meeks and Summers (2016) tested this question in Ranitomeya imitator, the Mimic Poison Frog, which shows pair-bonding and biparental care. The male and female cooperate to place tadpoles in tiny pools of water (phytotelmata), and then return to feed the tadpoles infertile eggs as it develops. They showed regulating food levels across development, tadpoles receiving less food increased begging levels significantly over the course of development, relative to tadpoles given more food. An experiment manipulating the amount of begging that tadpoles perform (under identical feeding regimes) revealed costs of begging in terms of developmental rate and growth. An experiment on parental feeding revealed that parents preferentially fed tadpoles not receiving supplemental food, relative to siblings whose diet was supplemented with extra food. They conclude that tadpole begging in this species serves as an honest signal of need. (Kyle Summers)

  • April 11, 2016: Although general convention says that stress reduces reproduction, a species’ length of breeding season and its lifespan also play a role. Woodley and Porter (2015) recently tested the interaction of stress, length of breeding season, and lifespan in Spotted Salamanders, Ambystoma maculatum, which are long-lived, explosive breeders, by comparing the time it took males to deposit spermatophores (sperm packages that females use to fertilize eggs) and how many spermatophores were dropped in males deliberately stressed by handling and control males. They found that, while there was not a significant difference in how long it took males to drop spermatophores, stressed males deposited significantly more. The authors suspect that this may be a strategy to increase reproductive potential when there is a greater risk to survival. (AChang)

  • April 4, 2016: The Rough-skinned Newt,Taricha granulosa, is engaged in an evolutionary arms race with its only known significant predator, the Common Garter Snake, Thamnophis sirtalis. In regions where snakes are absent (such as some islands near Vancouver Island, Canada), newt toxicity is low to absent, whereas in sites where toxicity-resistant snakes are common (various sites in California and Oregon), newt toxicity is high to very high. The authors of a new paper (Hague et al. 2016) studied newts in southeast Alaska, where snakes are absent, and as expected, toxicity levels were low at most sites examined. However, puzzling variation was found. In one lake on Wrangell Island, no toxicity was found, but newts from another lake on the same island displayed surprisingly high levels, rivaling those in some areas where snake predators have high toxin resistance. Various explanations are offered, but reciprocal selection does not fully explain the toxicity variation in newts. (DW)

  • March 28, 2016: A new report from Europe (Spitzen-van der Sluijs et al 2016) shows that the introduced chytrid pathogen, Batrachochytrium salamandrivorans (Bsal), spread from the Netherlands and Belgium into Germany, as previously predicted. This pathogen was only recently discovered and is related to the the fungal pathogen Batrachochytrium dendrobatidis (Bd) that has decimated amphibians globally as it has spread into naive populations. They analyzed 1019 skin swab samples collected from 55 sites. The infected animals were found at 7 sites in the Netherlands, 4 sites in Belgium, and 3 sites in Germany (total infected sites 14 of 55 sites). The study is important because it provides important data from the field on the current distribution of Bsal, and provides benchmark data extremely useful for the basic understanding of the dynamics of the host pathogen interaction for this newly emerging pathogen. (VV)

  • March 21, 2016: Most family-level radiations of frogs are continental. One of the few island archipelago radiations is the Ceratobatrachidae, a clade of 96 species on the islands of Southeast Asia and the Southwest Pacific. However, the closest relative of ceratobatrachids is unknown, and so the biogeographic origin of the clade is unclear. Yan et al. (2016) discovered that three species of Limnonectes (family Dicroglossidae) are more closely related to ceratobatrachids than to other taxa. Surprisingly, these species are from mainland China, where no ceratobatrachids were previously known. This discovery provides a biogeographic link for an enigmatic radiation of island frogs. (DC)

  • March 14, 2016: Plethodontid salamanders are more agile than other salamanders and they are known to jump, especially to escape predation. Ryerson et al. (2016) studied jumping in six species (three genera). All were capable of jumping by lateral body bending followed by rapid straightening, which propels the salamander into the air. Most likely force to propel the animal is applied through one or both hind limbs. Salamanders jumped a maximum of 1.8 times head+body length and jump height is scaled with body size and forelimb length. Species did not differ in any other aspects of performance, except takeoff velocity where longer salamanders are slower. No correlation was found between tail length, or even presence of a tail, and any variable. Further kinematic analysis is needed to understand how salamanders maintain jumping performance no matter the size. (DW)

  • March 7, 2016: How will amphibians respond to global warming? A new study by Orizaola and Laurila (2016) finds that three populations of the Pool Frog (Pelophylax lessonae) from the northernmost populations, isolated in the Uppland district north of Stockholm, Sweden, display greater thermal phenotypic plasticity than three populations from Poland (about the center of the species distribution) and Latvia (2 from northern-edge populations). The Uppland populations show greater temperature-induced plasticity affecting duration of the larval period, mass at metamorphosis, and growth rate, than other populations. All these variables are important in facilitating positive responses to periodic warm spells in colder environments with shorter growing seasons. Geographic variation in plasticity of life history components should be considered in predicting responses of particular species to climate change. (DW)

  • February 29, 2016: One of the most widespread amphibians has thought to be the Southeast Asian common toad, Duttaphrynus melanostictus, considered a human commensal that has widely spread by human actions. It was thus a surprise when Wogan et al. (2016) reported a high level of geographic and genetic structure in the species and the discovery of three distinct lineages: Asian mainland, coastal Myanmar, and Sundaic islands. These represent at least three and possibly multiple species, which have higher conservation value than currently recognized. The species complex has been introduced to such distant places as Borneo, Sulawesi and Seram, and even Madagascar. Which species have been introduced and what their ecological niches, geographic ranges, and dispersal potentials remain to be determined. (DW)

  • February 22, 2016: Tim Halliday has produced a beautiful book on frogs (The Book of Frogs: a life-size guide to six hundred species from around the world, Ivy Press). Following 37 pages of short but informative sections on aspects of frog biology, species accounts begin. The presentation is comprehensive and cosmopolitan, following a skeletal phylogeny from AmphibiaWeb. Each is headed by a short but informative data table and a map of the world showing distribution. Each account shows a full-size photo, and for all small species a large detailed photo, with carefully but interestingly written introductions to the species and information about similar species. Each account has a small drawing that enhances the presentation. The photos, mainly from AmphibiaWeb photographers, are well-chosen. All families and a surprisingly large number of genera are represented. This is a very entertaining and informative book –highly recommended!

  • February 15, 2016: Birds and mammals are well-known for their behavioral flexibility and learning aptitudes, but these traits are not as well-characterized in amphibians. Liu et al. (2016) investigated these traits in the poison frog Dendrobates auratus, a species with complex reproductive strategies that may favor highly flexible forms of learning. Experiments on serial reversal learning using a two-sided maze with distal visual cues revealed that the frogs could learn to identify the correct exit. Probe trials in which visual cues were switched demonstrated that the frogs relied on these cues. Serial reversals demonstrated that the frogs learned to learn more rapidly across trials, employing rule-based strategies to solve the maze with increasing rapidity, thus demonstrating high levels of behavioral flexibility and learning ability in an amphibian. (Kyle Summers)

  • February 8, 2016: Spadefoot toads (family Scaphiopodidae) are a familiar part of the North American frog fauna and relatively common in the North American fossil record. Chen et al. (2016) fill in an important gap in our understanding of this group with a fossil from the late Paleocene of Mongolia. Their work suggests that the two genera of living spadefoots (Scaphiopus and Spea) last shared an ancestor near the end of the Cretaceous. They also suggest that the presence of this early spadefoot frog in Asia supports dispersal into North America via Beringia in the Early Cenozoic. (DB)

  • February 1, 2016: In a new review, Alessandro Catenazzi (a member of the AmphibiaWeb Team) assesses the state of the World’s amphibians. The paper, filled with new information and ideas, is a thorough introduction to the issues involved in amphibian declines and attempts to combat them. The main focus is on immediate and new threats, ranging from infectious diseases to climate change. The status of amphibian conservation activity is surveyed and continuing threats (as from the recently discovered and apparently salamander-specific chytrid fungus) are evaluated. Synergistic effects are highlighted, as between disease and climate change. Catenazzi argues for more field studies of amphibian physiological ecology (for example, critical thermal limits). He discusses paradoxes, such as the discovery rate of new species while the taxon as a whole declines. His conclusion is that humans will need all their ingenuity, motivation and moral impetus to save amphibians. (DW)

  • January 25, 2016: Parental care in anurans usually takes the form of attendance of eggs. Male attendance of eggs laid on vegetation has evolved independently in two genera of the glass frogs, family Centrolenidae: within Centrolene and within Hyalinobatrachium. Now Valencia and Delia (2016) have discovered parental care in a third clade of centrolenids, Ikakogi tayrona, the geographically (Sierra Nevada de Santa Marta, Colombia) and phylogenetically isolated sister-taxon of all other centrolenids. Unexpectedly, the attendance in Ikakogi tayrona is by females. Care functions are similar in both males and females, but females are somewhat more risk-tolerant, probably reflecting the more direct link to fitness in females. (DW)

  • January 18, 2016: A reflection of the gravity with which the scientific community regards the Bsal “salamander-devouring” pathogen, the US Fish and Wildlife Service has issued an unprecedented ruling to address this biodiversity crisis. The ruling implements the Lacey Act by listing as injurious to wildlife, and thereby banning, 201 salamanders, mainly Asian species believed to be Bsal carriers and popular in the pet trade, from importation and interstate transportation. By specifically targeting the salamander species which are suspected to be susceptible to and carriers of the new chytrid fungus, the US FWS aims to protect the global hotspot for salamander diversity in North America, centered mainly in the US. The ban, broad in its scope yet specific in its named species, has yet to be tested as written to strike the balance between protection from an emerging infectious disease and ongoing research, which frequently requires transportation of samples and specimens. The interim ban is effective on January 28th and an open commentary period is available until March 14th. (MK)

  • January 12, 2016: A massive experiment in extinction prevention is underway in Panama, where many organizations and individuals are involved in a captive breeding program. An evaluation of the program (Gratwicke et al 2015) reports that 18 species are being held for conservation purposes, with numbers in captivity ranging from over 1,000 (Atelopus zeteki) to 1 (a single male of Ecnomiohyla rabborum). Of these, 5 are Atelopus species and the 6th is Gastrotheca cornuta and each are represented by at least 10 males and 10 females. An expert survey analysis (based on 1387 responses from experts for 215 Panamanian amphibians) ranks all species according to their perceived susceptibility to chytrid infection, probability of finding founders, probability of going extinct in the wild, and probability of avoiding extinction through captive breeding programs (using lower and upper bound for the three probabilities). The probability of successful captive breeding is medium to high for about 2/3rds of the Panamanian species but the challenge is daunting. Already about 4% of the species are missing. They conclude captive breeding could improve the odds of avoiding extinction for some species that have declined. Many of the species (notably salamanders, caecilians) are too rarely encountered to be part of the program. (DW)

  • January 4, 2016: Starting the new year on a positive note: Woodhams and colleagues (2015) recently created the Antifungal Isolate Database, nearly 2,000 strains of naturally occurring cutaneous bacteria with anti-fungal properties that are found on amphibians. This database will help researchers and managers select the appropriate strain for bioaugmentation to combat chytridiomycosis infections, help researchers find new strains with anti-fungal capabilities during whole genome sequencing, and predict how new strains will function. Two files are available are available now: (1) a FASTA file of the bacterial isolates’ 16S rRNA gene sequences and (2) a metadata of the 37 host species, host life stage, geographic region (12 countries from 5 continents), and the taxonomic identity and anti-fungal capacity of each strain. Once launched, they hope to continue to add new projects to the database, which could prove to be a powerful new tool in amphibian conservation. (AChang)


    • December 28, 2015: 2015 has been a good year for AmphibiaWeb-- we’ve seen our species accounts grow to 33% of all known amphibians (over 3,100 species accounts in total), which has also increased by 115 new species described in 2015. Our new accounts include French excerpts from Jean Raffaëlli’s 2nd edition of Les Urodèles du Monde for all salamanders, and contributions from students in seven herpetology classes around the US. Most importantly, we saw heightened urgency for a call to action against the latest threat to salamanders worldwide from a recently described chytrid fungus, Bsal. AmphibiaWeb and the US Forest Service joined a national task team to develop an Amphibian Disease portal to aggregate data and coordinate efforts in the field and lab to understand how to combat this emerging infectious disease. In 2016, we will launch this effort and will need your support to make a difference in amphibian conservation. Happy New Year's!

    • December 21, 2015: What were the musculoskeletal changes needed to transverse from water-dwelling locomotion to the much more demanding terrestrial life about 390 million years ago? Kawano et al (2015) asked this of the earliest tetrapod and examined Tiger Salamanders (Ambystoma tigrinum) as proxy. Specifically they measured bone loadings on the fore and hind limbs in a variety of ways assessing the 'safety factor' or margin of extra protection that a limb will take in excessive loads, and found differences when comparing the humerus and femur bones in the stresses they can withstand and experience while walking. Learning how these salamanders, which have similar morphology to the early tetrapods, locomote will allow better modeling and understanding of the biomechanics of our ancestors when they invaded land. (MK)

    • December 14, 2015: A new paper (Bosch et al. 2015) has garnered much attention because of its strong claim: the research team eradicated Bd, the pathogenic fungus of amphibians, from the island of Mallorca in the western Mediterranean. The small island harbors a single species, Alytes muletensis, discovered only about 35 years ago, and there are few breeding sites, mostly in nearly inaccessible deep canyons. Bd appeared a few years ago, probably arriving through human agency, and threatened the species. The team used a common fungicide (itraconazole) and with considerable effort eliminated infection from organisms and the environment; it took five years but it worked – so far. While this is an important proof of concept, application to other parts of the world is problematic. Environmental impacts of the treatment are left unexplored, and the problems of multispecies communities, direct developing species, species with multi-year larvae, among other issues, may render this approach of limited value. (DW)

    • December 7, 2015: A new approach to Bd as a global pathogen of amphibians is proposed by a team of active researchers. As an alternative to focusing on “hot spots” of chytrid infection, James et al. (2015) recognize that it is a global problem and argue for a reframing of questions related to distribution, so instead ask: “where are the cold spots of Bd distribution?” “why are they cold?” These could be artifacts of ignorance, or Bd might never have been present in these areas. Environmental conditions may be outside the tolerance window for Bd. They also suggest that Bd might have been present historically, but frogs evolved defenses (or only resistant species survived pathogen-driven selection); Bd later disappeared or persists at low prevalence. They refer to this as the “Ghosts of Epizootics Past” hypothesis and suggest that an important lesson learned so far is never stop sampling. They suggest that Korea might serve as a compelling control population because Bd is now enzootic in its amphibian fauna. (DW)

    • November 30, 2015: Disease dynamics are rarely simplistic and often difficult to reconstruct historically; chytridiomycosis is no exception. Sette et al 2015 examined chytrid prevalence using both historic museum and current field samples of the California Slender salamander, Batrachoseps attenuatus. From random samplings of about 30k museum specimens, they found that Bd emerged rapidly in Northern California and exhibited a non-linear pattern of spread. By resampling the historic positives sites, they were able to determine that modern-day persistence of Bd was negatively correlated with time since first detection of infection, suggesting that recent invasions were more likely to persist, and positively correlated with proximity to lentic aquatic habitat, suggesting that aquatic carriers of Bd may transfer it to terrestrial B. attenuatus populations. Interestingly, sociality was also suggested as an important factor in disease spread and populations exposed earliest to Bd showed lower probability of aggregation behavior in the field. (MK)

    • November 23, 2015: The expansion of Cane Toads (Rhinella marina) in Australia is well known, but the species has been widely introduced elsewhere as well. A new study (Narayan et al. 2015) focuses on the impact of its introduction into Fiji on the native frogs. This experimental study of frogs in enclosures and in nature showed that Fiji Ground Toads (Cornufer vitianus, formerly Platymantis vitiana) were adversely affected by the invasive species, which exploits broader ecological roles and has strongly negative indirect effects. Most importantly, there is a significant reduction in reproductive success, the probable result of high stress levels as reflected in hormone measures. (DW)

    • November 16, 2015: Defenses against predators are assumed to promote speciation because the defense provides a release from predation. Arbuckle and Speed (2015) examined the macroevolutionary effects of chemical defense and conspicuousness in amphibians and found that for conspicuous species the speciation rate was 2-3 times higher than for cryptic species, but the extinction rate was the same. In chemically defended amphibians, they show speciation rates were about 2 times that for undefended species. Surprisingly, however, the extinction rate was three times higher in lineages with chemical defense than without it. The authors suggest several explanations for this as well as suggest that understanding defensive traits may be instructive to predicting extinction. As important may be opening the discussions about conservation policies applied to higher at risk, chemically defended species and how we categorize them. (DC)

    • November 9, 2015: On November 8, 2015, Peru established an enormous new national park in the heart of the Amazon Basin. Parque Nacional Sierra del Divisor encompasses 1,335,000 hectares and abuts the Brazilian national park Serra do Divisor (about 843,000 hectares). Together both parks protect more than 2.14 million hectares (an area larger than the states of Connecticut and Rhode Island combined). Herpetologists M. Barboza de Souza and C. Rivera found 67 species of frogs and one salamander in 16 days of work during a Rapid Biological Inventory conducted in 2005 (Field Museum, RBI 17); doubtless many more amphibians occur in the area. The new park protects an area of diverse topography, highlighted by a scattering of impressive old volcanos. The actions of the governments of Peru and Brazil to preserve a vast area of extraordinary biodiversity value also protect the ancestral territories of several Amazonian indigenous groups. (DW)

    • November 2, 2015: An international team, composed of field biologists from the Palawan Centre of Sustainability, the National Museum of the Philippines, the Palawan Council for Sustainable Development, and the University of Kansas has recently rediscovered the long-lost Malatgan Caecilian, Ichthyophis weberi, from north-central Palawan Island, western Philippines. Discovered in the early 1900s, this species has not been observed in the field since the 1970s. Thought to have been possibly extinct, I. weberi may be a dry microhabitat specialist (found away from water in dry forest floor detritus), which has escaped detection by biologists who have searched in vain for the species in moist, riparian, or semi-aquatic microhabitats. The expedition also rediscovered the Palawan toadlet (Pelophryne albotaeniata), not seen in the last 40 years. (Rafe Brown)

    • October 26, 2015: The Amphibian Survival Alliance (ASA) and their partners have been hard at work creating protected areas. In August, they announced the creation of Ankaratra Massif Reserve in Madagascar, which was the result of a five-year effort to protect rare Madagascan endemics, such as William's Bright-eyed Frog (Boophis williamsi) among other amphibians and reptiles. In September, they announced the creation of the San Isidro Amphibian Reserve in Guatemala, where, in 2009, an international team of scientists, including UC Berkeley's Ted Papenfuss and Sean Rovito, rediscovered the Finca Chiblac Salamander, Bradytriton silus, and the Long-limbed Salamander, Nyctanolis pernix, which had not been seen in over 30 years. Still missing since its discovery in 1975 is the Jackson's Climbing salamander, Bolitoglossa jacksoni, also presumed endemic to the Sierra de los Cuchumatanes. With protection, we have hope to rediscover that species, too. (AChang)

    • October 19, 2015: Although the chytrid fungus, Batrachochytrium dendrobatidis (Bd), has been known to cause amphibian die-offs since the 1990’s, little work has been done to assess the long-term ecological consequences of disease-driven amphibian extirpation. Rantala et al. (2015) surveyed a Panamanian stream to determine if and how the structure and function of the aquatic ecosystem had changed over the 8 years since an amphibian die-off. They found a decrease in coarse organic matter and species richness of both macroinvertebrate and tadpoles. Furthermore, changes were seen in the nitrogen cycle that was not immediately apparent after the die-off. Interestingly, there was no evidence of functional redundancy or compensation by other species after the loss of amphibians, even after 8 years. The authors urge more studies of disturbed ecosystems over longer periods of time that measure multiple ecosystem functions to understand ecosystem processes. (AChang)

    • October 12, 2015: The recently described second species of pathogenic fungus, Batrachochytrium salamandrivorans (Bsal), was originally found in the southeast of The Netherlands and subsequently found in Belgium causing mass die-offs of fire salamanders. However, it has not yet been reported in other countries in natural settings. Sabino-Pinto et al 2015 reports a widespread infection of Salamandra (in four different species and 12 subspecies) in a captive-breeding facility in Germany. The source of the infection is unclear, but the very fact that Bsal is present in captive animals and that these animals may have been distributed elsewhere is deeply disturbing, and bears out the hypothesis of its possible spread from Asia to Europe. The paper also highlights the pivotal role of the pet trade industry in combatting this threat. (DW)

    • October 5, 2015: Many cases of overexploitation of amphibian species remain poorly documented because exploitation and consumption happen at very local scales. Recent work by Thomas & Biju (Salamandra 2015) extensively documents tadpole consumption in the endangered purple frog, Nasikabatrachus sahyadrensis – the sole species of the Nasikabatrachidae described in 2003. At a single study site in the Western Ghats of India, thousands of tadpoles were harvested per year, as well as adults. While potentially sustainable, the combination of heavy exploitation with annual variation in monsoon rains likely have a long-term negative impact on this threatened and biologically unique species. (DB)

    • September 28, 2015: Endocrine-disrupting chemicals in the environment are known to affect sex differentiation of amphibians during development. Agricultural pesticides are the most familiar environmental endocrine disruptors, but others include synthesized and natural estrogens (animal and plant). Lambert et al. (2015) found that in metamorphic Rana clamitans the bias toward females was higher in suburban ponds than in forested ponds. As well, the amount of suburban land use (residential landscaping) was related to higher levels of phytoestrogens (plant estrogens) in suburban ponds compared to forest ponds. This suggests that changes in land use are unappreciated sources of estrogen exposure to wildlife. (DC)

    • September 21, 2015: Conservation policy makers rely on the IUCN status of amphibians, of which the designation Data Deficient is the default category for species lacking information for placement. However, DD may be too simplistic, obscuring species that are safe with the threatened. Nori and Loyola (2015) quantify these DD species’ spatial relations to protected areas and heavily human-modified landscapes, and found that on average 81% of DD species’ ranges fall outside protected areas with much of it in human-modified landscapes, up to 58%. Regional variation among Latin America, SE Asia, Africa and Oceania is high and often alarming given the socio-political trends in increases of human-modified landscapes and decreases in protected areas. Their analysis of DD species gives a starting point to address otherwise ignored species. (MK)

    • September 14, 2015: The Central American amphibian fauna may be the richest in the world per unit area and it is one of the most endangered. Wilson et al. (2015; direct link to pdf) evaluate the status of the entire herpetofauna of the region, using their revised Environmental Vulnerability measure, which assigns scores (EVS) of 3 – 20 for all species. They assert: “We regard the IUCN system as expensive, time-consuming, tending to fall behind systematic advances, and over-dependent on the Data Deficient and Least Concern categories. Conversely, the EVS measure is economical, can be applied when species are described, is predictive, simple to calculate, and does not “penalize” poorly known species”. Of the 493 species of amphibians in the region, 70.8% have scores in the high vulnerability category (EVS of 14-20) and 92.4% of 159 salamanders evaluated are in that category. (DW)

    • September 6, 2015: Of the three orders of amphibians, Australia only has one native order, frogs (Anura). However, that changed when Tingley et al. (2015) recently reported on the successful establishment of the European newt, Lissotriton vulgaris in southeastern Australia. The introduction of L. vulgaris is believed to have occurred from escaped or illegally released pets before the species was listed as a "controlled pest animal" and its import subsequently prohibited. The potential ecological implications of this invasion are great as the European newt competes with native frogs and has the potential of producing a neurotoxin that to native predators have no evolutionary history with. Lastly, because the climate in southeastern Australia is similar to the native range of the species, L. vulgaris has the potential to spread across much of southern Australia and Tasmania. (AChang)

    • August 31, 2015: The large (nearly 400 species) family Rhacophoridae, widespread in the Asian subtropics and tropics with a few species in Africa, displays a great array of life history modes. A multigene, phylogenetic analysis of all major clades and nearly a third of the species in the family has enabled Meergaskumbura et al. 2015 to conclude that the ancestral mode was fully aquatic eggs and larvae. The ancestral forms of all but the most basal branches in the tree have a high likelihood of having been terrestrial gel nesters. Direct development and foam nesting characterize the vast majority of rhacophorids and have evolved independently at least twice within the family. As a probable consequence of these evolutionary events, rhacophorids thrive in diverse habitats across a vast geographic range. (DW)

    • August 24, 2015: To better understand why the fungal pathogen, Batrachochytrium dendrobatidis (Bd), varies in mortality outcome with different species, Stevenson et al. (2014) explored how host-specific body temperature at low and high elevations contribute to host Bd response. The authors incubated Bd cultures that mimicked temperatures experienced by three sympatric Litoria species, L. nannotis, L. rheocola, and L. serrata. The culture growth patterns were consistent with recovery rates in nature where the most varied thermal regime, associated with Litoria serrata at low elevation, had slower culture growth rates and a faster species recovery rate in the wild than L. nannotis and L. rheocola, which have a stable and less varied thermal regime, respectively. Their findings support the idea that natural temperature regimes affect the patterns of Bd-driven decline. (AChang)

    • August 17, 2015: No salamanders are known to occur on any of the Caribbean islands. Now a salamander has been found in a piece of amber from the Dominican Republic on the island of Hispaniola. The salamander, a tiny hatchling, has been named Palaeoplethodon hispaniolae, and it is thought to be a member of the family Plethodontidae, and in particular its clade Bolitoglossini, which includes more than 40% of all salamanders (Poinar and Wake, 2015). Bolitoglossines live exclusively in the New World tropics. The amber is dated between 15 and 40 million years. The discovery of this tiny, probably arboreal species should spur renewed attempts to find living salamanders on the larger Caribbean islands. (DW)

    • August 10, 2015: To be considered venomous, not just poisonous, a delivery system needs to be present. Recently Jared et al (2015) showed in two Brazilian frogs a novel method for venom delivery- through spikes in their heads. Corythomantis greeningi and Aparasphenodon brunoi both have bony spikes around the margin of the skull which can pierce through a bed of poison glands, thus injecting the venom into their would-be molesters. They have unusually flexible necks allowing them to twist and turn their heads. Further, they determined that the secretions were 2 times and 25 times more lethal than pitviper venom, respectively. While C. greeningi was able to deliver more venom, A. brunoi has a more lethal venom. (MK)

    • August 3, 2015: A moratorium on US salamander imports may be the best defense against the deadly salamander chytrid fungus, Batrachochytrium salamandrivorans (Bsal), which is poised to devastate North American amphibian biodiversity. Yet, the US Fish & Wildlife Service has not acted to ban imports of salamanders to the US, pending more studies of this recently discovered pathogen. A growing chorus of advocates for a temporary ban includes a new Science Policy Forum report (Yap et al 2015), which presents a salamander vulnerability model showing the regions most at stake. Specifically, the centers of salamander biodiversity in the Southeast US, Appalachia and the Pacific Northwest would be most impacted should Bsal enter one of the adjacent traffic ports. Prevention in this case is the best defense, as we have learned from the wave of extirpations caused by Bd, sister taxon of Bsal. AmphibiaWeb urges immediate action by responsible agencies. (MK)

    • July 27, 2015: It’s a busy time for AmphibiaWeb. Recently, the Society for the Study of Amphibians and Reptiles (SSAR) released their new online, searchable North American Standard English and Scientific Names Database, where you will find links to AmphibiaWeb species accounts for each amphibian. At the SSAR annual meeting at the University of Kansas (July 30th to August 3rd), Michelle Koo of AmphibiaWeb will present a vulnerability model of the alarming Batrachochytrium salamandrivorans (a.k.a. Bsal, the recently described chytrid fungus infecting salamanders) and our proposal for a centralized database to help combat Bsal and Batrachochytrium dendrobatidis (Bd). In fact, more than half of the AmphibiaWeb steering committee will be present, so come find our presentations. We look forward to connecting with you there!

    • July 20, 2015: In a rare example of publishing negative results, Labisko et al. (2015) recently reported the failure to detect Batrachochytrium dendrobatidis (Bd), the culprit behind the often fatal amphibian chytrid infection, in six of eleven amphibian-inhabited Seychelles Islands. These findings included 10 of the country’s 12 amphibian species, which include both frogs and caecilians; 11 are considered globally significant. These findings are particularly important because the climate, habitat, and introduction of Bd susceptible amphibians provide a high potential for Bd to gain a foothold in Seychelles amphibians. The authors recommend the effective implementation of the Seychelles Biosecurity Act and continued monitoring to ensure these unique amphibians stay protected. (AChang)

    • July 13, 2015: Amphibians display a wide spectrum of parental care, from abandonment after laying eggs to provisioning larvae with food after hatching or live birth, which has been considered a fixed trait. Ringler et al. (2015) tested that assumption in Allobates femoralis, a species in which males obligatorily transport tadpoles and females provide no parental care, after observing a small proportion of tadpole transportation by females over a 5 year period. Using both previously observed data and laboratory experiments with wild-caught individuals, the authors tested if mothers transported tadpoles when fathers disappeared. The statistical and experimental results consistently showed that females compensate for unavailable males by transporting tadpoles themselves. The authors urge more cautious labelling of uniparental care as it may oversimplify parental behavioral flexibility. (AChang)

    • July 6, 2015: Rana cascadae is in decline throughout much of its range, and its near extirpation in the Lassen Peak region of northern California was an early example of the general decline of amphibians that has attracted so much attention. Piovia-Scott et al. (2015) studied the relationship of the chytrid pathogen (Batrachochytrium dendrobatidis, Bd) to juvenile survival of R. cascadae in a lake in the Klamath Mts., and a lake in the southern Cascade Mts., northern California. In the first site, Section Line Lake, abundance of juvenile frogs declined by more than 99% between 2009 and 2012, and Bd was 5 times as prevalent as in the other lake, where no clear trend was recorded. Lab experiments showed that the virulence of Section Line Lake Bd was much greater than isolates from other lakes, and genomic differences were also recorded. The study highlights the significance of local processes in host-pathogen dynamics and population declines. (DW)

    • June 29, 2015: The Pine Barrens Treefrog Hyla andersonii is an enigmatic species that exists in three distinct geographic regions: southern New Jersey, the piedmont region of the central Carolinas, and the panhandle of Florida and immediately adjacent Alabama. Warwick et al. (2015) evaluated the species using bioacoustics, microsatellites and morphology, with the goal of making recommendations concerning taxonomy with special consideration for conservation. The guiding principle is Templeton’s conception of populations being conspecific if they display exchangeability. Data were strikingly concordant across the entire combined range, an unusual situation that argues in favor of continued recognition of a single taxonomic species. (DW)

    • June 22, 2015: Last Fall, we highlighted the deadly fungal disease, Batrachochytrium salamandrivorans, now also known as Bsal, which is especially lethal to salamanders having been discovered at sites of mass fire salamander die-offs in Europe (NYTimes Oct 2014). Martel et al 2014 reported on the first susceptibility tests of Bsal on salamander species revealing its lethality to North American taxa. Since then, the US amphibian conservation community has not been idle; several studies and petitions have launched. Indeed a call for banning salamander imports to protect North American species has been growing. One such initiative has been the formation of a Disease Task Team by PARC (read one-page brief here). Their first goal is to build a Strategic Action plan towards protecting North American biodiversity and natural heritage from the Bsal threat. (Browse North American salamanders through our lists by country and state). (MK)

    • June 15, 2015: The Cane Toad, Rhinella marina, has been evolving rapidly during its 80-year period of range extension across northern Australia. Extensively documented phenotypic changes in morphology, physiology and behavior suggest that the pace of change appears to be accelerating. A newly published study (Rollins et al., 2015) focused on gene expression reported differences across the historic – invasion axis, with substantial up-regulation of many genes, especially those involved in cellular repair and metabolism. Shifts in gene expression may well underlie the rapid evolution associated with range expansion. These findings open new research opportunities. (DW)

    • June 8, 2015: It is difficult to place current extinction rates into an appropriate time perspective, but in a new analysis of vertebrate extinctions, McCallum (2015) reaches shocking conclusions. Using IUCN/SSC Red List data, comparisons were made with 16 different approaches and 288 separate calculations. Vertebrate extinctions (using designations of Vulnerable to Critically Endangered) have exploded since 1980, with losses 71-297 times larger than end-Cretaceous events. If the analysis is extended to Data Deficient species, the magnitude approaches 8900-18,500 times the mass extinction of the past. The speeds and magnitudes are sufficiently great that present occurrences constitute a mass extinction, the sixth in Earth's history. (DW)

    • June 1, 2015: AmphibiaWeb team member David Blackburn, California Academy of Sciences curator, and digital artists at Ex'pression College (Emeryville, CA) produced an animated music video for Caecilian Cotillion. The Wiggly Tendrils wrote this lovely song last year to commemorate the 200th species of caecilian, those legless amphibians with secretive lives.

    • May 25, 2015: Cave-dwelling organisms are usually very different than their close epigean (surface-dwelling) relatives. However, cave and epigean forms are often genetically very similar, suggesting that morphological evolution has accelerated. Salvidio et al. (2015) studied foot morphology in Hydromantes strinatii, an Italian cave salamander that seems to be following in Gollum's footsteps. They showed that in a population in a 70 year-old artificial cave, the size and shape of the feet had diverged from that of an epigean population to resemble a the feet of a natural cave population. The larger feet of cave salamanders are thought to be adaptive, supporting a hypothesis of rapid morphological adaptation in response to a new environment. (DC)

    • May 18, 2015: The loss of a species' genetic distinctness via hybridization is a conservation concern sometimes difficult to identify and further impeded when the organisms are secretive and with low population numbers. Fukumoto et al (2015) recently overcame this problem by using environmental DNA, specifically DNA found in water samples, to determine the extent of hybridization between the threatened native Japanese Giant Salamander, Andrias japonicas, and invasive Chinese Giant Salamander, Andrias davidianus. After surveying 37 sites across the Katsura River Basin in Japan, they found 9 sites with exotic DNA, including sites that traditional methods excluded from having invasives. The authors recommend environmental DNA methods for monitoring the spread of hybridization in conjunction with traditional catch and release methods to provide a fuller picture for conservation efforts. (AnnC)

    • May 11, 2015: Hyla is a well-known component of the North American frog fauna. However, more than half of the species of Hyla are found in Europe and Asia. Two possible dispersal routes from North America into Eurasia are west-to-east (trans-Atlantic) or east-to-west (Bering Land Bridge). Dispersal over the Bering Land Bridge has generally been assumed, but has not been tested. Using a biogeographic analysis, Li et al. (2015) concluded that Hyla arrived in Eurasia by two dispersals over Beringia, at 20 mya and at 35 mya. Interestingly, although European Hyla are geographically closer to eastern North American Hyla, they are more closely related to East Asian Hyla. (DC)

    • May 4, 2015: Every herpetology student learns that all salamanders are carnivorous at all life stages, unlike frogs in which the larvae may eat a variety of foods and at least one species eats fruit as an adult. Recent work by Hill, Mendelson and Stabile (2015) has shown that a few species of sirenid salamanders willfully ingest vegetation even in the absence of animal prey associated with it. A literature review indicated that the phenomenon had been noticed during examination of stomach contents, but the observations were variously interpreted as ingestion incidental to foraging for animal prey. Future work on the digestive physiology and microbiota of sirenids is warranted. (Joseph Mendelson)

    • April 27,2015: Elizabeth Kolbert has won the Pulitzer Prize in general nonfiction for her book "The Sixth Extinction: An Unnatural History" in which she travels the world describing mass extinction events, untangling causes, and trying to understand solutions. From her publishers: "The Sixth Extinction" began as a New Yorker article of the same title, about crashing amphibian populations in Panama, and parts of the book were published in the magazine in the two-part series "The Lost World." The award is a recognition of both the power of Kolbert's writing and the urgency of her subject. As the subheading on her magazine piece read, "This time, the cataclysm is us." (VV)

    • April 20, 2015: Phenotypic plasticity in frogs has been known to range from variation in coloration to presence of spines and glands associated with reproduction. However, variation in skin texture has long been assumed to be limited, so much that the number, shape and distribution of tubercles, warts, and other skin protuberances is routinely used as a diagnostic character in species descriptions. The effectiveness of skin texture as a diagnostic trait is now questioned by Guayasamin et al. (2015)'s findings that in two species of the large frog genus Pristimantis, individuals have the ability to quickly change skin texture from tuberculate to nearly smooth. In addition to cautioning about the peril of ignoring intraspecific phenotypic plasticity when making taxonomic decisions, the new study hints at some intriguing hypotheses regarding the benefit of skin change abilities in these Andean frogs. (A slideshow of P. mutabilis remarkable ability.) (ACatenazzi)

    • April 13, 2015: In addition to humans, amphibians also benefit from probiotics. Certain bacteria in the skin microbiome of frogs inhibit infection by the chytrid fungus Bd, a deadly skin pathogen. This suggests a strategy that would allow re-introduction of a virtually extinct species, but, the solution is not simple. Becker et al. (2015) showed that in the Panamanian Golden Frog (Atelopus zeteki), application of bacteria that inhibit Bd in vitro did not do so in vivo. Survival was correlated instead with the composition of the pre-existing skin bacterial community. This indicates that information about the skin microbiome in natural populations may be useful for predicting susceptibility. (DC)

    • April 6, 2015: The fungal pathogen, Batrachochytrium dendrobatidis (Bd) , which causes chytrid infections in amphibians, is known to have varied effects on different species. In some, infection is lethal, while other species appear to be only carriers. Susceptibility to the fungus is thought to be related to the evolutionary history of exposure to Bd. Talley et al. (2015) recently investigated the historic presence of Bd in Illinois, where field surveys showed Bd presence without amphibian die-offs. Their testing of museum specimens of 10 species collected between 1888 and 1989 revealed that Bd occurred in four species (at rates between >7% and 38.3%, with the highest historic prevalence in Rana sphenocephala) from over 120 years ago. Their findings illustrate why evolutionary history is important for effective conservation management plans. (AChang)

    • March 30, 2015: Identifying the effects of climate change on amphibians is important. Connette et al. (2015) warns that ecological factors or systemic bias may be causing apparent body size changes that are attributed to climate change. Connette and colleagues conducted visual encounter surveys of Plethodon metcalfi and measured the body size (SVL) and other parameters of encountered animals for two years and conducted mark-recapture surveys of P. shermani for six years, all in southwest North Carolina. They found that large adult P. metcalfi were disproportionately represented in samples collected shortly after rainfall and towards the middle of the summer active season, with an 11% difference in mean body size across survey conditions. There was large annual variation in P. shermani in all age classes, with larger individuals more likely to be detected after rainfall. Connette et al. (2015) cautions that plethodontid salamanders may be particularly susceptible due to their fossorial nature and sensitivity to high temperatures and moisture, and this could easily lead to biases in surveys. Large multi-year, multi-season surveys are needed for accurate measures of population and body size variation. It is possible that climate change has resulted in selection for smaller adult body size in recent decades, but other factors, such as weather conditions, yearly variation, and exposure during sampling, can also affect findings. (CS)

    • March 23, 2015: As humans have changed global biodiversity, infectious diseases have risen and wildlife managers are faced with the question of how to respond to parasite transmission. Rohr et al. (2015) address this issue by conducting wetland surveys, predators-parasite foraging experiments, testing the effect of different predators on parasitic trematode cercariae infection rates of tadpoles, and mathematically modeling infection rates in frogs. They found that predator diversity decreased infection rate and that predators that feed on parasites but not the focal host (non-intraguild predators), were especially effective at keeping trematode densities down. The authors encourage the cooperation between the fields of biocontrol and disease management and further believe that identifying more traits in predators and hosts may help us combat parasite infections. (AChang)

    • March 16, 2015: Until now, only one genome from the >7,300 species of amphibians has been sequenced. Now, a group led by Chinese researchers from the Kunming Institute of Zoology (Sun et al 2015 PNAS) have produced the second, from Nanorana parkeri, a frog endemic to the Qinghai-Tibetan Plateau. Its genome encodes about 20,000 genes, a number similar to that of humans. At 2.3 gigabases, it is larger than that of Xenopus tropicalis, which is 1.5 gigabases. The addition of a second amphibian genome provides a new source of reference data that is crucial to our continued exploration of the evolutionary connections between genotype and phenotype. (DC)

    • March 9, 2015: Arkive’s Conservation Heroes series highlights Alessandro Catenazzi, one of AmphibiaWeb’s steering committee members, and we thought it would be a good idea to do so, too! Alessandro joined AmphibiaWeb in 2012 when he started working with our co-founder and Associate Director Vance Vredenburg. Further, he is a reviewer for the Red List Assessments. Since then, Alessandro has built an impressive record of research on Peruvian herpetology, chytrid disease, and new amphibian species discoveries. So far, Alessandro and his colleagues have described 16 new species of amphibians including Telmatobius ventriflavum, which he recounts the story of its discovery in the Arkive profile. (MK)

    • March 2, 2015: Scientists have documented that in response to climate change, the timing of breeding has shifting to earlier for many species, but the consequences of this phenomenon for populations and individuals are not known. Bernard (2014) investigated breeding and fecundity in six southern wood frog (Rana sylvatica) populations, and found that warmer winters were associated with earlier breeding in this species, and lower fecundity for females. Earlier breeding also led to slower larval development and changed the timing of metamorphosis to earlier. Changes in the amount of precipitation was not associated with earlier breeding but was correlated with female fecundity. The lower fecundity rates could be caused by increased energy consumption during the warmer winters, but it was unclear why changes in winter precipitation rates were correlated with frog fecundity. (CS)

    • February 23, 2015: In disease dynamics, the "dilution effect" predicts more diverse host communities will have decreased incidence of disease through a complex mix of host-interactions and habitat partitioning. Becker et al (2014) tested this effect of host diversity on chytridiomycosis dynamics with experiments on amphibian host species with a range of traits, from terrestrial to aquatic to arboreal and from multi-species to single species communities. They report that high host diversity led to reduced Bd infection by as much as 66.5 percent less than single species. However, ecological interactions are complex: while one frog, Brachycephalus pitanga, had decreased Bd infections in diverse environments, it may be causing its aquatic neighbors an increase in Bd infections through habitat displacement. (MK)

    • February 16, 2015: Here's a follow up on our January 5th Amphibian News on Limnonectes larvaepartus, the new frog species that was found to give birth to tadpoles. Kusrini et al. (2014) examined the bodies of gravid females to further elaborate on this mode of reproduction. They found several tadpoles being held in the translucent oviduct, which completely filled the abdominal space. Upon closer study, they saw some tadpoles had yolk reserves attached to them, though there were no feces within the oviduct. Scientists determined that the tadpoles feed from yolk reserves rather than the oviduct wall. The yolk reserves are sufficient to last them until birth, at which point they rely on an external food source. Dark particles found in the guts of the unborn tadpoles suggest that they may also consume feces and dead tadpoles before birth. (Gordon Lau)

    • February 9, 2015: Some brightly colored newts, such as Taricha, are defended from predators by tetrodotoxin (TTX) in their skin. But how do newts protect themselves from TTX, a deadly toxin? It is known that genetic changes in the genes for sodium ion channels provide the newts with resistance against TTX. Hanifin and Gilly (Evolution 2015) demonstrated that these same genetic mutations are present even in some newts that do not have TTX, such as Pleurodeles. More importantly, these changes confer on Pleurodeles a small amount of resistance to TTX. This may have opened an evolutionary path to acquisition of TTX as a defense in newts such as Taricha. (DC)

    • February 2, 2015: An important issue in climate change and its relation to disease incidence is acclimation to shifts in temperature and precipitation. Raffel et al (PRSB 2015) support results of earlier work showing that temperature increases could exacerbate the effects of chytridiomycosis because of lags in host acclimation. Chytrid growth was greater in Notophthalamus viridescens following a shift to a new temperature, relative to newts acclimated to that temperature. But there are also important interactions with other factors (e.g., precipitation, soil moisture) that need to be taken into account. The study highlights the complex interaction between environmental effects and disease dynamics. (DW)

    • January 26, 2015: Although navigation has been studied in many vertebrates, very little is known about amphibian spatial learning abilities. Pasukonis et al. (2014) studied homing in territorial male Allobates femoralis, a species that shuttle their tadpoles, to determine if experience played a role in spatial orientation. Using a harmonic direction finder, they found that animals translocated within a familiar range were able to use direct paths back to their territories while animals translocated to unfamiliar surroundings of similar distances, were unable to orient toward their territory. The authors concluded that poison dart frogs use spatial learning for navigation within a local area. (AChang)

    • January 19, 2015: Xenopus laevis, the African Clawed Frog, is the most studied species of frog. Google Scholar yields 19,700 hits in the last five years alone. Ironically, even an experienced field herpetologist would have trouble determining whether a frog was in fact Xenopus laevis. Furman et al. (2015) have solved this problem. Using a multigene analysis of ~183 individuals from throughout Sub-Saharan Africa, they demonstrated that specimens identified as X. laevis in fact represents four species (laevis, petersi, victorianus, and poweri), each restricted to a major geographic region of Africa. Although these names already existed in the literature, they were often applied to the wrong species. (DC)

    • January 12, 2015: As with humans, noise affects the sound transmission of frog calls. Flowing water is a common source of background noise, and stream frogs tend to call at a higher pitch, but why is this? The species may have evolved a higher-pitch call for more efficient transmission--the acoustic adaptation hypothesis. Or, species that call at a less-than-optimal pitch are "filtered out" by the habitat and don't call near streams - the habitat filtering hypothesis. Vargas-Salinas and Amézquita (2014) compiled data on 110 species of stream- and non-stream frogs. After correcting for phylogenetic relationships and body size (larger frogs on average make lower-pitched calls than smaller ones), they found that the habitat filtering hypothesis was better supported than the acoustic adaptation hypothesis. Thus, ecology, more than evolution, explains why stream frogs call at a higher pitch. (DC)

    • January 5, 2015: Amphibians display an amazing array of life histories. In a paper describing a new species of dicroglossid frog from Sulawesi, Limnonectes larvaepartus, Iskander et al. (2014) also describe a new life history specialization. As far as yet known, this is the only frog to give birth to tadpoles. Oviductal tadpoles are well provisioned with yolk and reach at least Gosner stage 35 prior to parturition. The tadpole seen above, at ca. stage 25, was released by a female on capture. There is no evidence that metamorphosis occurs in the oviduct. (DW)


    back to News by Year
    • Happy Holiday season from AmphibiaWeb. 2014 has been a very active year for us, with initiation of new sections: Educational Resources, Stories from the Field, and new efforts underway to develop Life History Trait database and Amphibian Diseases portal. More than 2,200 photos have been added to a database containing about 31,000 photos. During the year, 167 species have been added and our monthly literature listing continues its steady growth and timely production. If you enjoy AmphibiaWeb, help spread the word by visiting our Zazzle AmphibiaWeb Shop and consider making a donation to help ensure our continued success.

    • December 22, 2014: While Rana cascadae is relatively widespread in montane habitats from northern California into southern British Columbia, declines attributed to the chytrid fungus Batrachochytrium dendrobatidis (Bd) seem focused in northern California populations. Piovia-Smith et al. (2014) studied virulence of Bd from two lakes suffering declines, finding that isolates from the midst of the decline were more virulent and induced greater mortality of juvenile frogs than Bd isolated from a more stable frog population. In genomic studies, the virulent isolate showed unusual features, including chromosomal differences. Specific genomic and phenotypic features of Bd might account for differences in mortality within species from different localities, as well as differences among species of amphibians. (DW)

    • December 15, 2014: An emerging biodiversity pattern is that of single amphibian species that are widespread across a continent are found to be complexes of several cryptic species. These are species that are difficult to distinguish without detailed analysis of traits such as mating calls in frogs or DNA sequences. An extreme example is the species Dendropsophus minutus, which extends over several ecoregions, including the wet forests of Amazonia, the coastal Atlantic forests of southeastern Brazil, to dry scrub forest of the Caatinga. Depending on the region, the species occurs from sea level to 2000 m asl. Using mtDNA sequences, Gehara and 29 co-authors (2014) identified 43 lineages within the single "species," many of which may represent cryptic species. The distribution of one lineage covers more than 1 million km2. This broad-brush study is an important first step in documenting taxonomic and biogeographic patterns of Neotropical biodiversity that beg for deeper analysis. (DC)

    • December 8, 2014: Two phylogenetically-related, highly virulent CMTV (Common Midwife Toad Virus)-like ranaviruses have caused mass mortality in multiple, diverse amphibian species (3 salamanders, 3 frogs) in a national park in northern Spain. A new paper by Price et al. (2014) documents these amphibian host populations and follows them in real-time following emergence of these Ranavirus. Multiple amphibian species experienced mass mortality and population collapse at multiple sites in the region. This is striking example of a novel, generalist pathogen repeatedly crossing the species barrier with catastrophic consequences in an amphibian community and is the result of the introduction of a single viral strain. (CS)

    • December 1, 2014: While we have known some animals can sequester diet-based defensive compounds to pass onto their offsprings, it has rarely been shown that there is a behavioural component, such as a preference for such prey by these species. Kojima and Mori (2014) addressed this behaviour in the venomous Tiger Keel-backed snake (Rhabdophis tigrinus) which preys on many amphibians including the robust, toxic Japanese Common Toad (Bufo japonicus). In their field work and prey-preference experiments, they showed that female snakes preferentially sought out the more scarce toads when gravid versus behaviour in males or non-gravid females. By seeking out toads, these females are able to confer more defensive compounds to their offsprings, which may be an effective antipredator defense as well as a rich example of ecological interdependence. (MK)

    • November 24, 2014: Because of their biphasic life history, many amphibians regularly cross roads, where they risk death from vehicles. Under-road tunnels have been used to mitigate traffic mortality with varied success. However, experimental testing for tunnel efficiency has been limited. Hamer et al. (2014) tested tunnel efficiency using two species of Australian bell frogs (Litoria aurea and L. latopalmata) and one species of marsh frog (Limnodynastes peronii), which have very different reproductive seasons than frogs in the Northern Hemisphere. They found far fewer Australian frogs entered and crossed tunnels than northern hemisphere species. The authors attributed this difference to life history and recommend more testing of installed under-road tunnels to determine their efficiency in conservation. (AChang)

    • November 17, 2014: Who would have predicted that an undescribed, cryptic species of frog would be uncovered within New York City? In a recent paper Feinberg and associates describe Rana kauffeldi, a species previously confused with R. pipiens and R. sphenocephala. The new species has a narrow lowland distribution, from northern New Jersey to central Connecticut (including Staten Island), but based on calls, it might occur as far south as North Carolina. Its unique call gave it away, and genetic data confirmed its distinctiveness. (Listen to its call here.) Discoveries such as this are critical in efforts to preserve biodiversity, because few sites remain in the heavily urban area the species occupies. (DW)

    • November 10, 2014: Cryptic diversity takes on special focus in the past month when two newly described species were reported from well known city regions from opposite sides of the globe: New York City and Kochi, India. Using multiple lines of evidence, Feinberg et al 2014 formally described a new leopard frog (Rana kauffeldi) from New York City which ranges along the coast from Connecticut to New Jersey. In Kochi, India, another urban center, Biju et al (2014) described a new Golden-backed frog, Hylarana urbis, along with 6 other Hylarana species also with molecular and morphological data. Both these frogs highlight the dangers of cryptic diversity where new species are discovered already threatened with habitat fragmentation and habitat loss of unmeasurable degree. (MK)

    • November 3, 2014: Last year the second chytrid pathogenic for amphibians was discovered in western Europe. Batrachochytrium salamandrivorans (also known as Bs) seems to be more virulent than its congener. A new study tests susceptibility of salamanders and some other amphibians (Martel et al Science 2014). Exposure of 35 species (24 salamanders) to 5,000 zoospores for 24 hours resulted in most salamanders but no frogs or caecilians becoming infected. 41 of 44 specimens of Palearctic salamanders died, including 5 salamandrid and 1 plethodontid species. Bs was lethal to both North American salamandrids. Bs was present but tolerated by most east Asian salamandrids tested, leading the authors to suggest that Bs spread to Europe from Asia via the pet trade. (DW)

    • October 27, 2014: Carlos R. Vasquez-Almazan, Curator in the Museo de Historia Natural in Guatemala City, is the winner of the Sabin Award in Amphibian Conservation, administered by the Amphibian Survival Alliance this year. This award recognizes the impressive efforts of Carlos in guiding the establishment of new conservation areas in Guatemala, especially the Sierra Caral Reserve. Carlos is an active systematist and ecologist, with a strong focus of amphibian conservation. We show a video presentation of Carlos accepting the Whitley Award from the Whitley Fund for Nature in 2012. AmphibiaWeb congratulates Carlos Vasquez-Almazan for his outstanding efforts in conservation, now recognized by two major awards.

    • October 20, 2014: In a recent issue of Nature Communications, Twomey et al. (2014) report on the Peruvian frog Ranitomeya imitator, which has evolved to mimic locally abundant poisonous frog species. In a classic case of Mullerian mimicry, individuals of R. imitator vary dramatically across a narrow transition zone in which they closely mimic R. fantastica versus R. variabilis. Microsatellite markers reveal restricted gene flow across this transition zone, perfectly matching the transition of R. imitator morphological characters and mating calls. Mate choice experiments revealed strong evidence for assortative mating in R. imitator within the transition zone, proving that genetic isolation can arise from natural selection for mimicry. While it is unclear if these reproductive barriers arose through sympatry or allopatry, the results clearly point to a role for mimicry in the speciation process. (AZink)

    • October 13, 2014: The 10th Latin American Congress of Herpetology will be held in Cartagena, Colombia from November 30 to December 5th, concomitantly with the 4th Colombian Congress of Zoology. The rich scientific program includes nine herpetological symposia, seven of which will present novel findings on Central and South American amphibians. These symposia will cover biogeography, bioacoustics and communication, parental care, ecological physiology, effects of climate change, and conservation. Regular sessions will include evolutionary ecology, physiology, systematic, diversity, conservation, reproductive biology and behavior. Also in the program is a workshop on amphibian parasitology. With 775 presentations scheduled for the event, this meeting will be the largest gathering of herpetologists working in Latin America.

    • October 6, 2014: Pathogenicity in different organisms is known to decline through time in many instances. Voyles et al. (Ecol Evol 2014) conducted experimental studies of two cryo-archived isolates representing two lineages of the amphibian pathogen Batrachochytrium dendrobatidis (Bd). The results support earlier suggestions that Bd may evolve rapidly but also challenge the widely held view that pathogenicity will always attenuate, especially in the lab. This study is an important contribution for understanding the evolution of virulence in this pathogen. (DW)

    • September 29, 2014: The link between microbial communities and individual health is gaining strength in recent years. For amphibians, evidence grows that certain microbes may provide resistance to the fungal pathogen Batrachochytrium dendrobatidis which causes Chytridiomycosis, a leading cause of amphibian decline. Becker et al. (2014), investigated the differences in microbial communities in wild vs. first generation captive-reared Panamanian golden frogs (Atelopus zeteki); reintroductions of captive reared golden frogs has been one method of combating Chytridiomycosis. Although both wild and captive-reared frogs shared 70% of the microbial species, the authors also found significant differences in microbial diversity and richness with captive reared frogs, having on average more species bacteria, and wild animals having communities with greater evenness and phylogenetic diversity. The effects of these microbial differences are currently unknown, but could lead to the failure of reintroductions due to loss of immunity to local pathogens. Thus the authors argue for reducing time spent in captivity or raising captive-reared animals with non-pathogenic native substrates. (AChang)

    • September 22, 2014: Amphibian biologists studying chytrid infections in the tropics have found the highest prevalence in mid-elevation wet forests. Hotter lowland sites, especially in drier habitats, have experienced less impact of chytrid. Zumbado-Ulate et al. (EcoHealth, 2014) studied frogs at two sites in dry, lowland forest in northwestern Costa Rica, finding extremely low prevalence, and in those few frogs infected, low genetic equivalents. Such habitats serve as climatic refugia from chytrid, highlighting the importance of tropical dry forest conservation for preservation of species, such as Craugastor ranoides. (DW)

    • September 15, 2014: For the first time, the auditory apparatus of caecilians, a largely fossorial group of amphibians, has been examined and compared with other animals. Maddin and Sherratt (2014) hypothesized that caecilians would have similar inner ear morphology, specifically semicircular canals that morphologically maximise sensitivity to correspondingly complex physical stimuli, as other animals which demonstrate spatially complex behaviours like living underground and navigating in three-dimensions. Their comparative work within amphibians showed that caecilians and frogs had similar curved canals but caecilians had the largest sacculus of all amphibians (enlarged saccule had been noted in earlier studies) among other differences. Taken together, the inner ear of caecilians shows unique adaptations to fossoriality like increased sensitivity to ground-borne vibrations and degeneration of airborne sound detection. (MK)

    • September 8, 2014: A new study (Pyron 2014, Systematic Biology) of the biogeographic history of amphibians is based on an updated chronogram of 3309 species (about 45%) and existing molecular data. The Pangean origin and subsequent fragmentation into Laurasian (salamanders) and Gondwanan (frogs, caecilians) segments led to occupation of 12 global ecoregions. Earth history (fragmentation and connection) accounts for most patterns of dispersion, but there are three well-supported instances that require long-distance oceanic dispersal: pelodryadine frogs dispersing to Austroasia from South America, micrixalid frogs dispersing to India from likely African origins, and hyperoliid frogs in Madagascar dispersing from Africa. Numerous questions remain concerning details for specific clades, but the broad patterns of distributional history are fairly clear, and both vicariance and dispersal have been important. (DW)

    • September 1, 2014: Currently, the IUCN lists 24.5% of assessed amphibians as Data Deficient. Using high risk traits of life history, environment and habitat loss, Howard and Bickford (2014) predicted the extinction risk of Data Deficient species and found that they are likely to be more threatened by extinction than assessed species. Their models highlight regions of risk anomalies, areas in Central and South America, West Africa, and the island of New Guinea in particular. Models as these may become important tools for conservation assessment when species are deemed Data Deficient, or worse, have not been assessed as in the case of over 1,000 species of amphibians. (MK)

    • August 24, 2014: Tadpoles of tropical frogs show great diversity of anatomy and life history. A recent publication (Oberhummer et al., Zootaxa 2014) describes tadpoles of two megophryid frogs from Borneo (Leptobrachella brevicrus and Leptolalax dringi) that are highly specialized for living fossorially, in gravel beds of small, montane streams. Tadpoles of both species have an elongated, worm-like shape including a long tail and very small eyes. Knowledge of the diversity of tadpoles continues to grow as biologists spend more time in areas of amphibian megadiversity. (DW)

    • August 18, 2014: Peru is well known for its diversity of frogs, yet there have been relatively few field studies of glassfrogs (Centrolenidae) in this country. Research to date indicates that glassfrog diversity is higher in the northern Andes. However, a new study by Twomey et al. (Zootaxa 2014) suggests that part of this trend may be due to sampling effort. The authors conducted fieldwork in Peru, and using an integrative approach to taxonomy they uncovered 4 new species from the family. Their results indicate that more exploration in the Peruvian Andes will likely uncover a higher diversity of glassfrogs than that currently recognized. (Jesse Delia)

    • August 11, 2014: Mountain Yellow-legged Frogs (Rana muscosa and R. sierrae) were once the most commonly encountered vertebrates in the Sierra Nevada of California. Despite having 84% of the combined range included in National Forests or National Parks, both species have severely declined, and frogs have disappeared in 93-95% (minimal estimates) of historical sites. A large multi-agency report (linked here) summarizes the situation, supporting endangered status for the taxa and identifying chytrid infection, trout introductions and habitat loss, among other factors, as contributing importantly to the declines. Some potential remediation efforts are underway, and research is on-going. (DW)

    • August 4, 2014: Amphibian Survival Alliance (ASA) has launched a new online magazine aimed at children 7-14 years of age. As with its other quarterly publication, this one is called Frog Log Jr., which we are hosting on our Education section. AmphibiaWeb contributed the first article and looks forward to collaborating with ASA in the future to help educate young people about the importance and conservation of amphibians. Take a break to read it!

    • July 28, 2014: Color can protect frogs in at least two ways: Dull frogs are cryptic against the background and avoid detection, or conspicuous frogs are easy to detect, but usually have a defense so that predators learn to avoid them. It turns out that pattern, not just color, is also important. Qvarnström et al. (2014) show that video images of dull green Strawberry poison frogs, Dendrobates (Oophaga) pumilio, were inconspicuous to predators (chickens) whereas dull green frogs with blotched patterns were as conspicuous to predators as brightly colored frogs. So, a blotched pattern may provide an evolutionary pathway by which the transition between the adaptive phenotypes can be made. Moreover, blotching may constrain the frequency with which this transition can be made. (DC)

    • July 21, 2014: The chytrid fungus Batrachochytrium dendrobatidis (Bd) has had devastating impact on amphibian populations in many parts of the world and its impact continues, threatening efforts at captive breeding and reintroduction of species. A new paper reports that frogs studied can acquire resistance, behavioral, immunological or both. In experiments, McMahon et al. (2014, Nature) show that frogs exposed and infected by Bd, but subjected to temperature clearance, learn to avoid sources of infection. With forced exposure, the number of previous exposures was a negative predictor of reinfection and a positive predictor of lymphocyte proliferation, thus overcoming pathogen-induced immunosuppression. These results suggest several therapeutic approaches to dealing with Bd. (DW)

    • July 14, 2014: Bonne Fête! In honor of France’s quatorze juillet celebrations, we highlight French amphibians. France has 42 amphibian species, and only 3 endemic species which only occur in its island region, Corsica in the Mediterranean Sea: Discoglossus montalentii, Salamandra corsica, Euproctus montanus. France’s most widespread frog species is the Midwife Toad, Alytes obstetricans, which occurs in almost all parts of continental France but is currently in decline. While Alytes is not particularly known for its legs, France recognized the impact their famous cuisine of frog legs has had on their amphibian populations, and in 1980 banned commercial harvesting of native frogs. ‘Cuisses de grenouilles’ dishes served in France now depend on Asian imports of frogs. Many western European amphibians have core parts of their ranges in France, making it an important biogeographic crossroad. (MK)

    • July 7, 2014: Some amphibians appear to be genuinely rare, making it very difficult to assess their conservation status. A new paper (Batista et al. 2014 Zootaxa) describes two new species of Ecnomiohyla from Panama. Each is represented only by the unique holotype. Frogs of this genus are known as Fringe-limbed Treefrogs. They are large, spend their lives in forest canopies (laying eggs in bromeliads), and are generally encountered only by chance. (DW)

    • June 30, 2014: Everyone knows that frogs have sticky tongues. But, how sticky? A newly published study (Kleintiech et al. 2014) reports on direct measurements in Ceratophrys sp. (likely laboratory bred hybrids). Tongue adhesive forces were found to be very great, so great that they are beyond the body weight of even the very large (for frogs) species of this genus, and more than any potential prey. Adhesion is strong even in parts of the tongue that have low mucous levels, suggesting that surface profiles and material properties are likely to be important factors. Frog tongues are analogous to pressure sensitive adhesives, such as tapes. Sticky indeed! (DW)

    • June 23, 2014: Although many Neotropical salamanders are intimately associated with bromeliads, we know very little about which characteristics salamanders use to select bromeliads. In a study of two sympatric species on Volcán Pacaya, Bolitoglossa morio and B. pacaya, Ruano-Fajardo et al. (2014) report that the two species were found in the same bromeliads across several sites and selected bromeliads with similar characteristics. Salamanders were found more often in larger, cooler bromeliads, and larger salamanders were found in bigger bromeliads with higher pH. Large, cool bromeliads may provide an important buffer for salamanders against adverse environmental conditions, especially in harsh environments such as on the active Pacaya volcano. The fact that the two species selected similar bromeliads means that they probably partition some other element of niche space besides microhabitat. (Sean Rovito)

    • June 16, 2014: For some time biologists have known that amphibians in arctic environments survive the long winters by essentially freezing. A new paper (Larson et al. 2014) reports on tracking Rana (Lithobates) sylvatica in interior Alaska to their overwintering sites and monitoring subsequent activity. The frogs stayed frozen on average for 193 consecutive days, experiencing average minimum temperatures of -14.6°C, with 100% survival. Very high cryoprotectant (glucose, glycolipid) levels in the frog are hypothesized to enhance freeze tolerance. (DW)

    • June 9, 2014: The user-friendly field guide The Amphibians and Reptiles of Mindo, recently published by Alejandro Arteaga, Lucas Bustamante, and Juan Guayasamin, presents data on 101 species found in Mindo, northern Ecuador. Designed for students, naturalists, tourists, and scientists alike, each species account includes a list of field-diagnostic characters, natural history notes, outstanding photographs, and a map of the species’ distribution in Ecuador. A list of expert reviewers and a note on each species’ conservation status is also included. Twelve species found at Mindo have been described in the last 10 years, and additional species records are expected. Although no lungless salamanders have been recorded at Mindo, two species, Bolitoglossa biseriata and B. chica, occur nearby (10 and 18 km away, respectively). This book will stimulate further studies and promote the conservation of the diverse amphibian and reptile fauna in Ecuador. You can purchase or read online now. (RvM)

    • May 26. 2014: The Sixth Conference on the Biology of Plethodontid Salamanders was held in Tulsa, Oklahoma, May 18-20, 2014. The honoree was Steve Tilley, co-organizer of the first conference in 1972 and one of only a few to attend all conferences. Steve presented the Keynote Address, on geographic variation in Desmognathus and problems related to species delimitation. Speakers were mainly from the USA, but talks were given by scientists from China, France and Mexico. Both talks and posters featured many presentations by students. Following the conference, informal field trips in far eastern Oklahoma uncovered four species of Eurycea and one Plethodon. (DW)

    • May 19, 2014: The National Congress in Guatemala, in an overwhelming vote on May 13, approved establishment of the Sierra Caral as a National Protected Area. Within the reserve, on the Honduras border, is the Amphibian Conservation Reserve (ACR, Reserva La Firmeza), purchased with the support of many international organizations working with Guatemalan biologists. The new reserve covers 18,000 hectares and the ACR is 2,300 hectares, one of the richest areas for amphibians in Central America, with at least 35 species, many of which are endangered or critically endangered. This is a major victory in the on-going effort to conserve amphibians in Middle America. (DW)

    • May 12, 2014: While recent work has led to new understandings of the relationships of the frog family Brevicipitidae to other frog families, there has been little attention to the evolutionary history within these African frogs. Loader et al. (2014) provide a detailed phylogeny for the many brevicipitids in the eastern Afromontane region extending from Zimbabwe north to the Ethiopian Highlands. They find strong evidence that this family of rotund, sexually dimorphic frogs originated in the early Cenozoic, and suggest that the high diversity of phylogenetically important lineages in the Eastern Arc Mountains is the result of long-term forest stability. (DB)

    • May 5, 2014: Males of many glassfrogs provide parental care to their eggs. Recent research by Delia et al. (2014) found that Hyalinobatrachium fleischmanni embryos can time hatching to cope with delinquent dads. In this species, there is a lot of variation among fathers—some provide care for up to 19 days, while others abandon clutches as early as three. Working at a site in Sierra Madre del Sur of Oaxaca in Mexico, Delia et al. conducted a male removal experiment to determine if embryos hatch once abandoned. They found embryos hatched several days early when abandoned, but extended development when fathers continued providing care. (Jesse Delia)

    • April 28, 2014: Tadpoles of Occidozyga species have been reported to be carnivorous, preying on insects, even other tadpoles. Haas et al (2014) show new photographic evidence for the previously undocumented larval feeding behavior in O. baluensis, the Bornean Seep Frog, and detailed descriptions of the anatomical adaptations to accommodate their carnivory. They hypothesize that suction feeding is used for gaining prey, and that they are obligate carnivores. (MK)

    • April 21, 2014: The 200th species of caecilian is Ichthyophis multicolor from Myanmar (Wilkinson et al., 2014, Zootaxa 3785 (1) ). To commemorate this event, the California Academy of Sciences and AmphibiaWeb present a celebratory song, Caecilian Cotillion! Enjoy!

    • April 14, 2014: In 1983 Narins and Smith found that body size and call characteristics in males of the Puerto Rican species Eleutherodactylus coqui (the coqui frog) vary with elevation. At warmer, lower elevations, frogs were small, with short, high-pitched calls, whereas high-elevation frogs were larger, with longer and lower-pitched calls. Fast-forward 23 years to 2006: Narins and Meenderink (2014) re-studied the same sites; at a given altitude, today's frogs are smaller with shorter and higher-pitched calls. Based on temperature data, they suggest that these changes in calls result from a warming climate that has displaced populations to higher, cooler regions. If these climatic changes continue, male calls may change to the point where females no longer recognize and respond to the mating calls, which likely would be detrimental to mating success and its survival. (DC)

    • April 7, 2014: Woodland Salamanders (Plethodon) in the southern Appalachian Mountains of the US have responded to climate change by shrinking. Caruso et al. (2014) studied 102 populations of 15 species and found that six Plethodon species have shrunk significantly in overall body size over a 55 year period. The proximal reason is that modeling shows that metabolic rate has likely increased by 7 – 8%, leading to the plastic response in phenotype. Amphibians appear to be more susceptible to environmental change than previously thought, and the current plastic response might well lead to an adaptive response. (DW)

    • March 31, 2014: The presence of predators are known to induce morphological changes in amphibian larvae, a form of phenotypic plasticity. What happens when tadpoles are exposed to introduced predators, like the Red Swamp crayfish, a common invasive species? Nunes et al (2014) experimented with nine Portuguese species (including Iberian endemic Discoglossus galganoi), exposing tadpoles to dragonfly larvae or crayfish cues to measure induced phenotypic plasticity and almost all (8 of 9) altered their morphology with the native predator but only four did in the presence of the non-native crayfish. The variation in responses, including changes in timing of metamorphosis, obviously have implications in predicting the impact of invasive species on amphibian declines. (MK)

    • March 24, 2014: Increasingly Google is the first reference source if you are seeking a comprehensive list of all amphibians in North America. As online information becomes more ubiquitous, the availability of books containing the same information have declined. Countering this trend, herpetologists M. J. Fouquette and A. Dubois have released "A Checklist of North American Amphibians and Reptiles (vol. 1 – Amphibians; reptiles will follow, published by Xlibris, 2014). Fouquette and Dubois' book is not a re-hash of existing information, but includes several novel uses of scientific names, especially of subspecies. A "checklist" is a technical reference that treats all species and subspecies of a taxon in a particular geographic region. It includes extensive information on taxonomy and distribution. The classical checklist is much more than a list. Despite the obvious importance of these, no checklist of the species and subspecies of amphibians of North America, either online or in print, has been available since the "Checklist of North American Amphibians and Reptiles" by K. P. Schmidt in 1953. (DC)

    • March 17,2014: The Rio Frio Salamander, Ambystoma leorae, long ago disappeared from the heavily polluted stream where it was first found. The stream-adapted species, once included in the no longer recognized genus Rhyacosiredon, has been rediscovered (the last report of a surviving population is 1983). A new study (Sunny et al. 2014) reports that the critically endangered species persists in a single population on Volcan Tlaloc, located adjacent to what may be the largest and densely urbanized area on earth. The salamanders, found in two small streams, show low genetic diversity but high average heterozygosity, and three genetic subpopulations were recognized in the restricted geographic range. While it is good news that the species persists, its habitat is very restricted and it remains at high risk of extinction. (DW)

    • March 10, 2014: Late in February 2014, a disturbing discovery was made in Ireland. At a lake in the open flatlands of The Curragh, Kildare, up to 300 frogs were found dead. The cause of the mass die-off remains mysterious but the Herpetological Society of Ireland have taken water samples for testing and urge the public to report any other mysterious frog deaths. (More information is posted on their website.) Although the dead and dying frogs, Rana temporaria, are listed as Least Concern by the IUCN, it is only one of three amphibian species known to Ireland and is a protected species in the Republic of Ireland, where populations have declined from mostly habitat alteration. (MK)

    • March 3, 2014: The chytrid fungus (Batrachochytrium dendrobatidis, Bd) is known to have caused amphibian population collapse and extinction in disease outbreaks globally. The origin of Bd is still unknown, but the timing of emergence in different regions is becoming better characterized. Using qPCR, Rodriguez et al. (2013) tested over 2,700 amphibian specimens collected in Brazil from 1890-2010 for the presence of Bd. They found a mean prevalence of Bd infection of 23.9 % over the sampled time period. They report divergent strains of Bd in Brazilian amphibians and suggest that Bd was not introduced to Brazil via the bullfrog trade. The authors conclude that Bd has been enzootic (endemic) in Brazil for over a century. (VV)

    • February 24, 2014: The eastern slopes of the Andes and the neighboring western Amazonian lowlands in South America house remarkable levels of biodiversity. A new survey of Peru's Manu National Park and its buffer zone (Catenazzi et al 2013) found more amphibian and reptile species than in any other protected area worldwide (155 amphibian and 132 reptile species). Their study also highlights the impact that the chytrid outbreak in the upper portions of the protected area (previously reported in Catenazzi et al 2011) have on species richness. The newly reported species list includes seven imperiled amphibian species and two reptile species. Hear from the investigators in a video of AmphibiaWeb's Rudolf Von May and Alessandro Catenazzi. (MK)

    • February 17, 2014: Woodland plethodontid salamanders play major roles in forest ecosystem dynamics. They are the most abundant vertebrates in many forests, and they are such major predators that they depress invertebrate species populations, thus retarding decomposition and enhancing leaf litter retention. This contributes importantly to carbon sequestration. Best and Welsh (in Ecosphere 2014) used experiments to show that a single Ensatina in a 1.5 m2 enclosure increased litter retention by 13.3%. The contribution of salamanders to ecosystem dynamics in general and to carbon sequestration have been under appreciated. (DW)

    • February 10, 2014: Many conservation efforts for amphibians concentrate on protecting aquatic habitats, yet numerous species have both aquatic and terrestrial life stages. A new study used stable isotopes and stomach contents (from both live animals and museum specimens) to analyze food web linkages for the threatened California Red-Legged Frog ( Bishop et al 2013). The stable isotope data found that 99.7% of this frog's diet came from terrestrial prey. Wet and dry season stomach content samples flushed from live frogs had 90% terrestrial prey, and museum specimens contained 82% terrestrial prey. These data suggest that conservation efforts should protect not only aquatic habitats necessary for reproduction (these frogs have aquatic larvae) but also protect surrounding terrestrial habitats, emphasizing the conservation importance of understanding food web linkages between amphibians and their prey, both aquatic and terrestrial. (VV)

    • February 3, 2014: The African microhylid frog Phrynomantis microps lives unharmed in the nests of ants that are normally highly aggressive to intruders. These ant nests provide the frog with a retreat from predators and also a humid environment during the dry season. Rödel and colleagues (2013) studied the skin secretions of this frog and isolated two peptides that inhibit the aggressive behavior of these ants. These peptides seem to interact with the ants chemoreception and disguise the frogs as either a nestmate or, at the least, as not an intruder. (DBlackburn)

    • January 27, 2014: Alexander von Humboldt and A. R. Wallace are among the renowned naturalists who pioneered the study of Amazonian biodiversity, hundreds of years ago. Despite a long history of exploration, a large number of new amphibians continue to be discovered. The key to these discoveries lies in the use of genetic data for species detection. A monograph, published in the open access journal ZooKeys (Caminer and Ron 2014), found 11 candidate species among populations of what were previously considered two widespread species, Hypsiboas calcaratus and Hypsiboas fasciatus. Based on genetic samples from populations across six countries, the team lead by Marcel Caminer (Museum of Zoology at Catholic University of Ecuador), found unequivocal evidence of the existence of a large number of cryptic species. The genetic results were corroborated with detailed analyses of male calls and body shape and color. The study formally describes four of the new species identified. (Santiago Ron)

    • January 20, 2014: Herpetologist Robert Inger wrote "A frog is a frog is a frog." Frogs have a body plan that has not changed for 200 MY, suggesting an evolutionary constraint. But is this true? Body plans may be related to life-style such as arboreal or fossorial habits, or alternatively, constrained by evolutionary history. Vidal-García et al. (2013) analyzed the Myobatrachidae of the Australo-Papuan region, a radiation with a remarkable diversity of sizes and shapes. Examining the relationship between environmental variables (such as temperature, humidity, topographic slope) and body measurements, they found no clear relationship between environmental niche and body size or shape when taking phylogeny into account. In seeming contrast, they also found that long-legged frogs inhabit wet areas and short-legged species inhabit dry areas. Intermediate species are found in a diversity of habitats. What this means is that both phylogeny and environment are important for "frogness"; evolutionary history has constrained the radiation of certain clades into specialized habitats. (DC)

    • January 13, 2014: Siphonops annulatus is a direct-developing caecilian, abundant in Brazil and northern South America, known for an unusual form of maternal care. The mother coils around her clutch of eggs, and the young hatch late in their development. They immediately commence eating the outer layers of the mother’s skin, which has become thickened with lipids and turns pale gray rather than the more normal blue-black. Gomes et al. (Zoology, 2013) have carefully documented the metabolic, endocrine, and relevant morphological changes that take place during the reproductive cycle of these dermatophagic (skin eating) caecilians. Their study contributes extensive data and analysis that aid in understanding the cycle and the skin response, and constitutes a baseline for endocrine studies of reproduction in caecilians generally. (MHW)

    • January 6, 2014: 2014 is the Year of the Salamander so it is fitting to highlight a report of the first antimicrobial peptides isolated from the skin of a salamander, Cynops fudingensis, a red-bellied newt from China (Meng et al 2013). Specifically this is only the second amphibian species found to have β-defensin antimicrobial peptides, besides the frog Rana chensinensis, although defensin peptides are known from other vertebrates. Likely this is part of the salamander’s immune system, however, its exact role is still speculation and worthy of further investigation. (MK)


    back to News by Year

    • December 30, 2013: AmphibiaWeb ends 2013 with good news! Once again Mendis Wickramasinghe and his team (2013) have rediscovered a frog species from Sri Lanka that had been declared extinct. Pseudophilautus hypomelas, described by Guenther in 1876 based on 14 specimens and not observed for 137 years, was found between 750 - 1400 m elevation in the Peak Wilderness Sanctuary in the Central Hills. This is the third species thought to be extinct that was rediscovered by this team. About 40 individuals were observed, and three collected as vouchers, in habitat that is under high levels of threat. A change of status from Extinct to Critically Endangered is suggested.

    • December 23, 2013: AmphibiaWeb wishes all our users and contributors a safe and happy holiday season! 2013 was a productive year for amphibians and AmphibiaWeb with 146 new species, 944 new photos, 30 new recordings, 62 new species accounts and more to AmphibiaWeb; we are especially grateful to contributors who make AmphibiaWeb possible. As an educational, non-profit organization reliant on donations and grants, we ask those of you making year-end gifts to consider including AmphibiaWeb; funds go directly to support AmphibiaWeb’s mission in amphibian conservation and scientific synthesis.
      Enjoy artwork from the cancelled film, Newt, courtesy of Pixar, as a nod to the upcoming Year of the Salamander, 2014!

    • December 16, 2013: Robert C. Stebbins, who died recently at the age of 98.5 years, published several classic studies on amphibians, notably his monograph establishing the ring-species Ensatina and his study of their natural history. His early book on Amphibians of Western North America was a ground-breaking study, which led to his well-known field guides. His last book, on California amphibians, was published in 2012. All were illustrated by him. At the time of his death, colleagues and friends wrote to express their condolences. Their memories and an interview with him published a few years ago in Copeia are part of a memorial document that stands as a tribute to a remarkable scholar, educator, communicator and artist. Also read a preview of his 2012 memoir, Connecting with Nature, the out-of-print California Amphibians and Reptiles (1972) and the out-of-print The Lives of Desert Animals in Joshua Tree National Monument with Alden Miller (1964).

    • December 9, 2013: Stynoski et al. (2013) reports from observations and experiments conducted on the Strawberry Poison frog, Oophaga pumilio from the Poison Dart frog family, that toxic alkaloids are present in all life stages, not only as adults. However, if tadpoles are fed eggs of a non-toxic and unrelated frog, they have fewer alkaloids than when fed conspecific nutritive eggs. This suggests that provisioning by females contributes significantly to adult toxicity. Further, the ability of Strawberry Poison frog females to arm tadpoles with alkaloids may offer an explanation for selective advantage of nutritive eggs.(DW)

    • December 2, 2013: The frog family Rhinodermatidae has just two species in the genus Rhinoderma, called Darwin’s frogs, which are restricted to Chile and Argentina. Discovered by Charles Darwin during his voyage on the HMS Beagle, Darwin’s frogs are known for their unique reproduction of their tadpoles developing in the vocal sac of their male parent. Sadly, these frogs are in trouble: the Chilean endemic R. rufum has not been seen since 1980, and R. darwinii has experienced population declines in Chile and Argentina. Soto-Azat and collaborators (2013) investigated whether chytridiomycosis was involved in the disappearance of R. rufum and decline of R. darwinii in Chile, by testing museum specimens and live frogs for the presence of the fungal pathogen with quantitative PCR. Among museum specimens, all infected Rhinoderma had been collected from 1970 to 1978, suggesting an introduction and onset of the epizootic during that decade. Among live frog populations, the prevalence of infection in sympatric amphibians was much higher in sites where Darwin’s frogs had become extinct or severely declined than in sites where they had not declined. These findings implicate chytridiomycosis for yet another group of amphibians that suffered enigmatic declines over the past four decades. (ACatenazzi)

    • Novermber 25, 2013: One of the defining characteristics of amphibians is their unusual skin. Many people know about the poison-dart frog species which produce neurotoxins on their skin to protect themselves from predators. Their bright colors advertise the fact that they are dangerous. In fact thousands of species likely produce compounds that serve to protect and also to communicate with conspecifics. Little is known however about the microorganisms that live on amphibian skin. A new study (Kueneman et al. 2013) uses high throughput DNA sequencing to describe the microbiota of 5 species of California amphibians. The study reports that microbial assemblages are strongly influenced by the species of host amphibian and they differed systematically from the microbial assemblages in their environments. This suggests that the skin microbiome and the amphibian hosts have close symbiotic relationships and may play an important role in amphibian host phenotype including disease resistance. (VV)

    • November 18, 2013: Conservation studies typically focus on creating management recommendations in isolation from public attitudes towards species. A recent study by Reimer et al. (2013) used social science techniques to investigate how knowledge of the eastern hellbender (Cryptobranchus alleganiensis alleganiensis) affected individual attitudes toward the species. They found that amongst survey respondents who were unfamiliar with the species, when given a little information about the rarity and threat level of hellbenders, participants were more likely to have more positive attitudes toward the species. Increased information did not affect the responses of individuals familiar with the species, who also tended to have the most positive attitudes. But those who were unfamiliar and not given more information had the most negative attitudes. Their work shows the importance of public outreach when making management decisions about rare and/or threatened species to ensure smooth adoption of conservation measures. (AChang)

    • November 11, 2013: Introduced Rhinella marina in Australia co-occur with many different species of native frogs. Lab experiments by Cabrera-Guzmán et al. (2013) show that tadpoles of three native tree frogs (Litoria) have negative effects on toad tadpoles by direct exploitative competition. These findings suggest that reintroduction of native frogs into areas where losses have occurred may be an effective method of controlling the introduced toads. (DW)

    • November 4, 2013: Is similarity in morphology, ecology, and performance (e.g. jumping, swimming, etc., abilities) across species assemblages caused by evolutionary convergence or by dispersal of evolutionarily conserved ‘ecotypes’? Moen et al 2013 analyse the ecology, morphology and performance of frog assemblages from Asia, Australia and South America to see whether biogeographic dispersal or convergent evolution best explained similarities across continents. They report three conclusions: 1) microhabitat similarities fostered convergence of morphology and performance no matter clade or continent; 2) in other species, similarities relied more on dispersal of evolutionarily conservative groups; 3) at least in one clade, Litoria, its arboreal specialist ancestor radiated into a range of microhabitat specialists, thus the exception to ecologically conservative dispersal. (MK)

    • October 28,2013: Competition with non-native species is often cited as a possible cause of decline in amphibians. Researchers in France (Cayuela et al 2013M) tested this hypothesis with the native threatened yellow-bellied toad, Bombina variegata, and invasive marsh frog, Pelophylax ridibundus while also taking into account three differences in their biology: breeding pond preference (pond-area dependent), palatability to predators (fish dependent), and adaptations to variations in hydroperiod (floodplain-width dependent). The researchers found that the two species were infrequently found in the same ponds and that pond area was the best factor explaining their cohabitation with species co-occurring in ponds of intermediate size. The results indicate that there is little competition between the two species and thus marsh frogs, in this case, are not contributing to the decline of yellow-bellied toads. (AChang)

    • October 21, 2013: Batrachochytrium dendrobatidis (Bd) occurs in caecilians (Gower et al 2013). More than 200 specimens specimens from Africa and South America were field-swabbed. Of the 4 families, 7 genera, and 8 species of African caecilians sampled, Bd was present in nearly all (except Schistometopum); it was not present in any of the 4 families, 5 genera, and 10 species examined from South America. Mortality, apparently from Bd, occurred in captive Geotrypetes seraphini, both field-caught and from the pet trade. It is important to sample caecilians because Bd heretofore had been reported only from batrachian amphibians (frogs and salamanders), and better understanding of the natural history of Bd and the conservation threat it poses will be gained from broader taxonomic and geographic sampling. (MHWake)

    • October 14, 2013: Well-preserved and articulated frog fossils are uncommon, but fossils preserving the external anatomy of frogs are exceedingly rare. A recent study by Laloy and colleagues investigates the internal anatomy of a "frog mummy" found in the 19th century in France. By studying the skeleton of this unique specimen, we now have a "face" for an enigmatic genus of frogs (Thaumastosaurus) known from the early Cenozoic of western Europe. The detailed study of the skeleton, which included parts previously unknown for this extinct genus, reveals affinities to ranoid frogs in Africa rather than to ceratophryids from South America as thought for the past several decades. (DBlackburn)

    • October 7, 2013: The Neotropical harlequin toads, Atelopus, have been extirpated from much of their original range, and the fungal disease chytridiomycosis is a proposed culprit for many of the extinctions. Most of the remaining harlequin toads are in lowland areas where elevated temperatures are thought to limit the growth of the fungus. Sandra Flechas and collaborators have explored an alternative hypothesis that symbiotic skin bacteria protect the toads from chytridiomycosis. The researchers compared the anti-fungal properties of cutaneous bacteria among three species of Atelopus. They found that A. elegans was infected with chytrid fungus near sea level on a tropical island, despite high temperatures, as well as harbored bacteria with the strongest anti-fungal properties among the three species examined. Thus, the cutaneous bacteria may enhance fitness by preventing or delaying the symptomatic phase of chytridiomycosis, and are candidates for the development of probiotic treatments against chytridiomycosis. (ACatenazzi)

    • September 23, 2013: In Memoriam - Robert Stebbins, 1915 - 2013.
      We are sad to announce the passing of Bob Stebbins, a friend, a colleague, Curator and Professor Emeritus at the Museum of Vertebrate Zoology, UC Berkeley. He was 98 years old and his impact on us professionally and personally go far beyond the field of herpetology.

    • September 16,2013: Partners in Amphibian and Reptile Conservation (PARC) has designated 2014 as the Year of the Salamander. They are holding a logo contest, the deadline for submissions is October 1, 2013 as well as a photo contest for a monthly photo with inclusion in a calendar. For more details see PARC news. Look forward to a year of salamanders!

    • September 9, 2013: Batrachochytrium dendrobatidis has been written here many times as the chytrid fungus that causes the deadly disease chytridiomycosis, a leading cause of amphibian declines. When the devastating population crash of fire salamanders, Salamandra salamandra, in the Netherlands failed to turn up Bd, An Martel and colleagues (2013) uncovered a new species of Batrachochytrium, newly named B. salamandrivorans. They report on its lethality as well as its apparent lower thermal preference and resistance in the midwife toad (Alytes obstetricans), indicating differences in these closely related chytrid fungi. (MK)

    • September 2, 2013: Glass frogs are not as delicate as their name may imply. A recent study documented aggressive territorial behavior among male Red-Spotted Glass Frogs, Nymphargus grandisonae (Hutter et al. 2013). Males were found to engage in repeated fights across multiple nights that sometimes resulted in injuries, hypothesized to be from this species’ characteristic humeral spines. The researchers also described six distinct types of calls in this species, including advertisement, courtship, territorial, encounter, distress, and release calls. View a video of dueling frogs from the authors. (Allie Byrne)

    • August 26, 2013: A scientific team from the California Academy of Sciences, including AmphibiaWeb's David Blackburn, recently returned from an expedition to the Cameroon highlands in West Africa bearing an exciting cargo. Several species of live frogs including Cardioglossa gracilis, C. pulcra, Hyperolius ademetzi, H. riggenbachi and Xenopus longipes returned with the team to start as the core of an initiative to study their biology and thus better inform conservation efforts. 38% of Cameroon's amphibians are Critically Endangered, Endangered or Near Threatened, which makes this project all the more urgent. Little is known about the basic life history and reproductive biology of these species but that will hopefully change with this captive breeding study underway. Read more about this at KQED Science. (MK)

    • August 19, 2013: Microcaecilia is a genus of what are thought to be common caecilians in South America; of the 12 known species of Microcaecilia, over half (7) were described only in the last three years. The most recently discovered species is Microcaecilia marvaleewakeae from the Guianan region of northern Brazil, where Maciel and Hoogmoed (2013) distinguishes this delicate, violet-colored caecilian from M. taylori, also from the region. This new species presents intriguing new questions about the biodiversity of these caecilians. It is notable for also being named in honor of Dr. Marvalee Wake and her work on caecilian morphology, reproductive biology, development, physiology, and evolution. (MK)

    • August 12, 2013: Free-living tadpoles are known to have many morphologies that are often attributed to adaptations to their environment. Recent work by Rowley et al. (2012) describes a novel morphology from an oophagous, tree-hole dwelling tadpole, Rhacophorus vampyrus. These tadpoles have two backwards-facing hook-like teeth, which gives the species part of its common name, Vampire Flying Frog. Given the angle, it's unclear how the teeth are used in feeding, but the authors speculate that the hooks are used to flip trophic eggs into its wide mouth when feeding. (AChang)

    • August 5, 2013: The amphibian chytrid fungus (Batrachochytrium dendrobatidis, or Bd) is widespread in South Africa (Tarrant et al. 2013 in PLOS ONE). All threatened South African amphibians occur within the limits of the predicted distribution of Bd, in the wetter eastern and southern parts of the country. Bd was present on 14.8% of individuals tested belonging to 17 threatened species, but no adverse effects are reported, thus supporting the view that Bd is endemic to the region. (DW)

    • July 29, 2013: A new, richly documented study (Foden et al. 2013) of susceptibility to climate change among birds, amphibians and corals finds from 24% (optimistic) to 44% (pessimistic) of amphibians are highly vulnerable. Among the most vulnerable taxa are hemiphractid frogs, especially Gastrotheca, and plethodontid salamanders. The Amazonia is the most vulnerable area for amphibians. The authors conclude that global policies to mitigate greenhouse gas emissions have the potential to substantially reduce vulnerabilities. (DW)

    • July 22, 2013: Over the past two decades there has been an abundance of reports on amphibian declines. However, the rate of population losses has not been documented. Using data from the U.S. Geological Survey's Amphibian Research and Monitoring Initiative (ARMI) between 2002 and 2011, Adams et al. (2013) calculated the probability of amphibian occupation of ponds and other habitat in the United States for 45 species. Monitored sites included protected land with conservation policies in place. They found that overall occupancy declined at an annual rate of 3.7%, and species considered “Endangered”, “Vulnerable”, or “Near Threatened” by the IUCN declined at a rate of 11.6%, while species considered “Least Concern” by the IUCN declined at a rate of 2.7%. Amphibian declines appear more critical than first expected as even Least Concern species and those in protected areas are in decline. (AChang)

    • July 15, 2013: How has Batrachochytrium dendrobatis (Bd), the fungal agent of chytridiomycosis, become so widespread? Vredenburg et al. (2013) bolsters a long held theory that the global distribution of Xenopus species for the pet-trade and biomedical uses may have facilitated the spread Bd. Testing 178 museum specimens, they found positive Bd results from 2.8% of Xenopus specimens collected in the 1930s in Africa, and 13% positive Bd rate from frogs collected from the wild in California. Given that established populations of Xenopus were documented in the wild in California as early as the 1970’s, these finding support the hypothesis that Bd could have been introduced from Africa to North America via Xenopus laevis or Xenopus tropicalis. (AChang)

    • July 8, 2013: Reintroduction of amphibians to sites that have experience local extinctions is an increasingly popular conservation strategy. A new study (Zeisset & Beebee 2013) of introductions of Bufo bufo in Great Britain has shown that size of the introduced population (>1,000) and the presence of different genotypes, derived from a geographically and environmentally distant location, are the most important variables in successful transplantations. Local adaptation was shown to evolve relatively rapidly. (DW)

    • July 1, 2013: Some good news about Mexican frogs! Stream-breeding hylids have been difficult to find in the Mexican Oaxacan highlands. Recent fieldwork (Delia et al. 2013.) reports the rediscovery of six species missing from recent surveys including Plectrohyla thorectes which had not been seen in 28 years. Delia et al also found Exerdonta abdivita which represents a new location for this little known species. Despite the other rediscovered frogs, the authors note some species of concern that have yet to be seen. (DW)

    • June 24, 2013: Bad news for Darwin’s frogs (Rhinoderma)! A detailed analysis (Soto-Azat et al. 2013 ) of the distribution and status of the two species finds that no specimens of Rhinoderma rufum can be found and it is inferred that the species became extinct about 1982. Furthermore, R. darwinii has declined more than previously thought, although it still has a broad distribution, the authors suggest its status be changed from Vulnerable to Endangered. (DW)

    • June 17, 2013: The enigmatic Martinique Volcano Frog Allobates chalcopis, discovered in 1984 and not seen since the 1990s, has been rediscovered. This species is the only dendrobatid frog known from the Caribbean islands. Fouquet et al. (2013) revealed it still exists, and that its assignment to Allobates is correct and is genetically distinct from all other Allobates studied (the geographically closest species occur in northeastern South America). This frog occurs above 800 m elevation to the summit (1390 m) on Montagne Pelée. The authors argue that its conservation status should be changed from the current Vulnerable to Critically Endangered. The curious distribution is thought to be the result of overwater dispersal, possibly as long ago as the Late Miocene. (DW)

    • June 10, 2013: Not seen for nearly 60 years, the Hula Painted Frog from northern Galilee, Israel, was rediscovered in November 2011(Biton et al. 2013). The Hula frog continues to surprise as it is a true rediscovery of a ‘living fossil’! Not only does it still exist in a tiny remnant of the once vast Hula wetlands, it is a representative of a clade of large frogs otherwise known only from fossils occurring from the Oligocene to Pleistocene. The rediscovered species, properly re-named Latonia nigriventer, is also the largest living member of the family Alytidae. (DW)

    • June 3, 2013: Developmental biologists (Bloom et al 2013) have experimentally shown that only a handful of molecules control the gut morphology of tadpoles as diverse as the herbivorous African Clawed Frog (Xenopus laevis) and the carnivorous-and often cannabalistic- Budgett’s Frog (Lepidobatrachus laevis). Exposing Xenopus laevis embryos to specific molecules altered their gut morphology to resemble those of the carnivorous tadpole species, despite 110 million years since their last common ancestor. The reverse procedure on Budgett’s Frog likewise reverted their guts to the herbivorous condition. A remarkable new method for identifying the developmental mechanisms underlying ecologically and evolutionarily important variation. (MK)

    • May 27, 2013: It's not surprising that amphibians lose body mass when food and water are limited, but a recent study by Bendick and Gluesenkamp (2013) has found that at least one species, Eurycea tonkawae, exhibits reversible decrease in body length during drought conditions. Using six mark-recapture surveys, which took advantage of unique markings on each individual, the researchers took measurements of individuals before and after an unusually extreme drought season. They found that many of the individuals had significantly decreased body length by reducing their intervertebral space immediately after the drought, but later recovered length to greater than their initial sizes. The authors hypothesize that the smaller body length may be an adaptation to extended periods of limited food availability. (AChang)

    • May 20, 2013: Prevalence of the highly virulent amphibian chytrid fungus varies among species, elevations and seasons in places where the disease has become endemic. While we knew that the fungus in culture grows best between 17 and 25 Celsius, the effect of a frog’s thermal behavior on chytrid infection was unclear. A new study (Rowley and Alford 2013) shows that in three species of stream-breeding rainforest frogs (Litoria lesueuri, L. serrata, L. nannotis), the frog’s probability of chytrid infection declines as they spend more time above the fungus upper optimum temperature of 25 C. The frog’s temperatures were tracked daily at four sites and over several seasons. These findings highlight the potential role of variation in thermal preferences among individuals in determining individual susceptibility and population-level differences in prevalence of infection. (ACatenazzi)

    • May 13, 2013: Genomic analysis reveals a complex evolutionary history. Genome sequences of 29 isolates of Batrachochytrium dendrobatidis (Bd) from around the world combined with data from 20 previously published isolates show that this potent amphibian pathogen has a complex history (Rosenblum et al. 2013). It is neither new, nor very old (the root is estimated at 104,000 years old and the Panzootic lineage at 26,499 years), and thus it fits neither the novel pathogen nor the endemic hypothesis, but parts of both. The pool of genetic variation is deeper than previously thought. The need to identify specific mechanisms associated with shifts in virulence remains acute. (DW)

    • May 6, 2013: Here's a problem: if you cannot tell the sexes apart, how can you effectively conduct captive breeding as an option for endangered species? Geocrinia, which has 3 of its 7 species listed as Critically Endangered to Vulnerable, are typically monomorphic, meaning little physically distinguishes males and females, and now Hogan et al (2013) shows that a noninvasive test based on the frogs' poop can sex them reliably. Using enzyme immunoassays, the ratio of testosterone metabolites and estrone conjugate metabolites indicates whether the origin of the sample was an adult male or female 100% of the time. The test was a little less reliable in juveniles. While hormonal assays are often used in behavioral ecology, this study demonstrates a utility in conservation as well. (MK)

    • April 29, 2013: Female amphibians are typically larger than males. The common explanation for this difference in size- sexual size dimorphism, or SSD- is that selection for more offspring favors larger female size ("fecundity advantage"). Some evidence indicates that sexual selection may favor the opposite pattern, males > females, when males fight each other for females or territories ("male combat"). Using phylogenetic comparative methods and published data from 550 frog species on body size, male combat, clutch size, egg size, and parental case, Han and Fu (2013) found no relationship between male combat and SSD, contrary to previous studies, and only a weak association in some taxa between fecundity and SSD. Across all frogs, however, they unexpectedly found that parental care, especially male parental care, best explained reduced size dimorphism between males and females. Han and Fu's favored explanation is "relaxed fecundity," meaning that because parental care promotes offspring survival, the female is not under intense selection to maximize fecundity through increased body size. However, they admit that the other two hypotheses are not unequivocally rejected. (DC)

    • April 22, 2013: Rhacophorid frogs achieve remarkably high diversity on Borneo, where 41 species are known. A rich array of life histories are displayed by these frogs, and expanded molecular systematic studies reveal that direct development has evolved independently in Philautus in SE Asia (including many on Borneo) and in Pseudophilautus/Raorchestes in South Asia (Hertwig et al, 2013). Borneo is a significant amphibian diversity hotspot, a result of repeated dispersal and vicariance events. (DBW)

    • April 15, 2013: The geographic range of the California Red-legged Frog, Rana draytonii, has been rapidly contracting to the north and west in southern California in response to encroaching urbanization (Richmond et al. 2013). The problem is exacerbated by periodic devastating fires and floods, with increasing difficulties for repopulation. Extinction debt of this sort will likely lead to more range restriction in the absence of aggressive management activities. (DBW)

    • April 8, 2013: Wickramasinghe and colleagues (2013) recently described 8 new species of Pseudophilautus all from an elevational gradient within one of the last remaining protected high elevation cloud forests in Sri Lanka, the Sripada World Heritage Site (Peak Wilderness). This is also home to the rediscovered Pseudophilautus stellatus, thought to be extinct for 160 years until last year (see March 11, 2013 News Box). This genus of rhacophorid frogs, numbered at 85 species including 16 extinct species, is entirely centered in Sri Lanka with many species known from a single locality. The new species are no exception and all but one are considered Critically Endangered. (MK)

    • April 1, 2013: Aquatic salamanders feed using a "Gape and Suck" mechanism, with the mouth and throat expanding and drawing the prey into the mouth. New studies of feeding in Andrias davidianus (Heiss et al. 2013) reveal that their feeding mechanism differs from that of fish in that the suction is the result of rapid opening of the very broad jaws, and that throat expansion does not involve much active involvement of the hyobranchial apparatus. (See video.) This key innovation is thought to have freed the hyobranchial apparatus for independent evolution, leading through a long series of intermediate conditions to the extreme specialization associated with tongue-feeding in terrestrial salamanders. (DW)

    • March 31, 2013: On March 31, 2013, raise a toast to celebrate the 98th birthday of Robert C. Stebbins, Professor and Curator Emeritus, University of California at Berkeley. Bob remains active in his retirement and is now writing his memoirs, having already two other books in his 90s. While Bob is best known for his field guides of Western North American herpetology, he was also a pioneer crusader for conservation in general and for amphibians and reptiles in particular. He has published many scientific papers, notably his monograph on the Ring-species complex Ensatina in 1949, and is an accomplished artist. AmphibiaWeb extends our best wishes to our friend and colleague.

    • March 25, 2013: Each winter tons of de-icing salts, sodium chloride (NaCl) and magnesium chloride (MgCl2), are used on highways. Hopkins et al. (2013) studied the effects experimentally on embryonic survival and development in rough-skinned newts, Taricha granulosa. At environmentally relevant levels, both salts have severe effects. However, they also found variation among newt families, showing that natural selection leading to local adaptation is at least a possibility. But it may be too long to wait for adaptation, and action is required to reduce the negative environmental effects of road salt.(DBW)

    • March 18, 2013: Johnson et al. (2013) highlights the intersection of evolutionary history, restoration ecology, and conservation biology by testing three Tiger Salamander types found in California - Ambystoma californiense, Ambystoma tigrinum mavortium, and their hybrids - in experimental pools with different drying schedules. Illustrating the adaptive differences in the three types of Ambystoma, they found that non-natives and hybrids did the best in pools that dried more slowly, like man-made ponds in the highly modified California landscape, while natives did the best in pools that dried out more quickly and which simulated more naturalistic ponds found in California. (AChang)

    • March 11, 2013: What may have been the world's most elusive frog, Pseudophilautus stellatus from Sri Lanka, last reported in 1853, has been discovered living in high elevation cloud forest in the Peak Wilderness of Sripada World Heritage Site (Wickramasinghe et al. 2013). The species is unusually large and colorful, but occurs in nearly inaccessible terrain. This was the first shrub frog described from Sri Lanka and it has long been considered to be extinct. Although in protected habitat (only 4.7% of Sri Lanka's original rainforest survives), the area is suffering from forest dieback phenomenon and the expansion of invasive species, so its continued survival is not assured. (DW)

    • March 4, 2013: Batrachochytrium dendrobatidis (Bd) has extirpated amphibian populations and entire species, particularly frogs, in Central and South America. Although the fungus is known from all continents, many continental regions have not been sampled. Using DNA-detection methods and skin analysis, Penner et al. (2013) sampled 61 frog and 1 caecilian species, from seven West African countries from a variety of altitudes, habitats, and life histories. They also used environmental niche modeling (ENM), to predict the occurrence of Bd in the regions sampled. Thus, failure to detect the fungus would reflect its genuine absence. Although ENM predicted suitable environmental conditions for the fungus, no samples harbored Bd. Their analysis showed that the westernmost occurrences of previously documented occurrences of Bd stop at the Dahomey Gap, a naturally non-forested area. Localities at which the fungus was predicted by ENM but not found, are all west of the gap, suggesting it’s a true barrier. They suggested the most likely human-mediated mode of entry would be along transportation routes. (DCC)

    • February 25, 2013: The effects of dams are well documented on fish species (e.g., salmon) but less is known about how dams affect amphibians. A recent paper in Conservation Biologyshows that dams negatively affect river-breeding frogs in California, such as Rana boylii. Kupferberg et al uses 20 years of frog breeding data from regulated (dammed) and unregulated (un-dammed) rivers to show that by altering the flow regime, dams are causing higher egg and tadpole mortality. Dammed rivers that add artificial peak flows in summer months, for example for boating recreation, are the worst for native amphibians. (VV)

    • February 18, 2013: In tests of the effects of fungicides, herbicides and insecticides on Rana temporaria in Germany, Brühl et al. (2013) found that applications at rates recommended on product labels led to mortalities as high as 100% (fungicides Headline and Captan Omya). All pesticides led to mortalities ranging from 20% to 100% after 7 days exposure at the label rate. Three products showed mortalities of 40% after 7 days exposure at levels one-tenth the label recommendation. These pesticides are widely applied, and it is evident that current regulations are not protecting amphibians living near application sites. (DW)

    • February 11, 2013: Parallel races to characterize amphibian biodiversity and at the same time to conserve it are mutually interdependent, argue Crawford et al. (2012). Using DNA barcoding methods, the authors sampled frogs in the ex situ collection of the El Valle Amphibian Conservation Center in Panama. Much genetic diversity was found. Three of ten species sampled displayed substantial genetic diversity. Whether species are described or not (e.g., Hemiphractus fasciatus could be divided into two or even three species), the authors argue that genetic data are central to establishment of successful captive assurance colonies. (DW)

    • February 4, 2013: A new quantitative, geographical analysis of Ecuadorian amphibians finds that chytridiomycosis and climate change are more likely causes for declines and extinctions than habitat loss (Menéndez-Guerrero & Graham 2013). Climatic niche properties of species appear to serve well as surrogates of the extinction risk of species (from IUCN Red List) and may prove useful as predictors of the vulnerability of species to climate change. Climate change, chytridiomycosis, and their synergistic interactions are likely having the greatest current impact on Ecuadorian frogs. (DW)

    • January 28, 2013: Amphibians play a prominent role in a recent re-evaluation of Wallace's famous work (1876) on zoogeographic regions of the world (Holt et al DOI:10.1126/science.1228282). It underscores the striking perceptiveness of Wallace. The authors compiled distributional and phylogenetic information for more than 21,000 species of amphibians (6110 of the 7089 currently recognized), birds and mammals. They identify 20 zoogeographical regions, which in turn they group into 11 larger realms, improving on Wallace's original interpretations. For amphibians, 19 zoogeographic regions are identified. Spatial turnover is greater in more southern parts of the world, where regions show the highest degrees of phylogenetic differentiation. Not surprisingly, Australia, Madagascar, and Atlantic regions of South America are species-rich areas that show the highest levels of phylogenetic uniqueness. (DW)

    • January 21, 2013: First described in 1998, the Tanzanian Kihansi Spray toad, Nectophrynoides asperginis, was already considered critically endangered. A dam built in 2000 reduced the spray from the waterfall which was critical for the toad and its habitat. A sprinkler system was later built to recreate pre-dam conditions. However in 2003, the populations plummeted due to a combination of chytridiomycosis, a sediment flushing dam operation, and a sprinkler failure during the dry season. The last record of this toad was in 2004, 6 years after its description. Fortunately, the Wildlife Conservation Society collected 499 individuals in 2000 and had them bred in several US zoos. Only 70 were left in 2004, until their requirements were understood, and as soon as 2012, the first attempt to reintroduce the toad was successful. Since then, 2500 US bred Kihansi Spray toads have been reintroduced to their native habitat. (JW)

    • January 13, 2013: Alternative hosts of the fungus Batrachochytrium dendrobatidis (Bd) that is responsible for many local and regional declines of diverse species of amphibians have been difficult to locate. Now a team of researchers (McMahon et al. 2013) has shown that crayfish (two species of Procambarus) in southeastern Louisiana harbor Bd zoosporangia within their gastrointestinal tracts. In experiments, crayfish, but not mosquitofish, were infected and held infection for more than 12 weeks. Bd was successfully transmitted to uninfected tadpoles of Rana sphenocephala. Exposure to water that had held Bd led to trauma and death in crayfish, suggesting that the fungus releases some chemical that has negative effects. These discoveries open new avenues of research on Bd and the possibility of its control in natural settings.(DW)

    • January 7, 2013: What causes amphibian mass die-offs? Although such events were often dismissed as circumscribed events in the past, they are now of great concern for conservation. Determining the cause of die-offs can be challenging and requires the integration of monitoring and analytical techniques. Rosa et al. provide an example of this approach by presenting evidence that an outbreak of chytridiomycosis caused a mass die-offs and population declines of the midwife toad in the mountains of Portugal. In the die-off triggering the study, hundreds of post-metamorphic toads were found dead in a national park in August 2009. Prevalence of chytrid infection in tadpoles in the region currently ranges between 15% and 100%, with some tadpoles being highly infected. Historically, the species occupied a much broader range in these mountains, suggesting that chytrid outbreaks may be linked to population declines, especially at elevations above 1200 m. (Alessandro Catenazzi)


    back to News by Year

    • December 24, 2012: AmphibiaWeb wishes you a safe and happy holiday season! We are grateful to the many citizen scientists, researchers and students who have contributed photos, recordings, species accounts and more to AmphibiaWeb. As an educational, non-profit organization reliant on donations and grants, we ask those of you making year-end gifts to consider including AmphibiaWeb; all funds go directly to support AmphibiaWeb and our mission in amphibian conservation and scientific synthesis. We look forward to 2013; we plan to roll out more new features to better serve the global community.
      Happy Holidays!

    • December 17, 2012: Most species formation in amphibians involves vicariant events and allopatry (Vences and Wake 2006). The discovery that very close relatives with small ranges occur together suggests that adaptive (e.g., ecological or behavioral) factors acting parapatrically or even sympatrically may have led to species formation. Vences et al. (2012 in Amphibia-Reptilia, 33: 503-520.) discovered that a new species of Malagasy treefrog, Boophis narinsi, is the closest known relative of B. majori, with which it is syntopic, or sharing the same habitat and range. The species differ slightly in molecular traits and have different male calls. The authors think the species arose in close proximity and suggest that other tropical species complexes should be investigated closely. (DBW)

    • December 10, 2012: The world's 100 most endangered species includes several amphibians; this week, AmphibiaWeb highlights the Dusky Gopher frog, Rana sevosa, (also Lithobates sevosus) which had a historic range in the longleaf pine forest uplands and wetlands throughout the southeastern US. Its known range is now severely limited to only one county of Mississippi of 60-100 individuals. Habitat destruction and chytrid disease threaten this species. Although listed as Endangered by state and federal agencies, and Critically Endangered by the IUCN, more surveys are needed to monitor the sole known site and potentially discover more populations for protection before this species goes extinct. (MK)

    • December 3, 2012: What are the implications of amphibian loss for ecosystem dynamics? Whiles et al. (2012) undertook such studies in the Rio Maria in the eastern part of the Cordillera Central of Panama before (2006) and after (2008) a predictable (Lips et al. 2006) massive die-off and local extinction event caused by arrival of the infectious chytrid fungus (Batrachochytrium dendrobatidis). Typically such streams have harbored on the order of 18 co-occurring species of frogs and densities exceeding 50 individual tadpoles per square meter. Losses led to a 98% reduction of tadpole biomass and a corresponding increase of more than twice previously recorded levels of algae and fine detritus biomass, as well as a 50% reduction in nitrogen uptake rate. Grazing invertebrates did not compensate for the loss of tadpoles, as had been predicted. Loss of amphibians thus has ecosystem-wide consequences. (DBW)

    • November 26, 2012: Fossils contribute to the Tree of Life because they provide times for the splitting of branches in the tree. Based on fossils and DNA data, we can date the earliest split in the salamander tree at about 183 Ma (million years ago), in the Early Jurassic. This split resulted in two major branches of living salamanders: Cryptobranchoidea- Hellbenders (Cryptobranchus) and Giant Salamanders (Andrias) and Salamandroidea, all other salamanders. Until recently, all known Jurassic fossil salamanders (146-200 Ma) have been on the cryptobranchoid lineage, not the salamandroid lineage. Gao and Shubin (2012) reports the first Jurassic salamandroid fossil, and named the Chinese fossil Beiyanerpeton, from deposits that are roughly 157 Ma. These animals were about 100 mm and were neotenic, as evidenced by impressions of the external gills. Their analysis shows that Beiyanerpeton lies deep on the stem leading to living Salamandroidea, thus filling the gap, as predicted, between the previously oldest salamandroid, Valdotriton, at 115 Ma, and the first branching event within living salamanders. (DC)

    • November, 19, 2012: IUCN's list of the 100 most endangered species includes several amphibians; this week, AmphibiaWeb highlights the sole salamander, Neurergus kaiseri. This strikingly colored newt is only found in three streams in the semi-arid Zagros Mts. of Iran, where not only local damming and introduced predatory fish, but also illegal poaching threaten these fragile populations. Despite CITES Appendix 1 listing, it is estimated there is less than 1,000 mature adults left in the wild. IUCN recommends steps to monitor and enforce laws against illegal trade, ensure habitat restoration and further legal protection. Over the next few weeks we will highlight other highly threatened amphibians from the report. (MK)

    • November 12, 2012: Color polymorphism in amphibians is widespread but has been relatively little studied. Bell and Zamudio (2012) have examined sexual dichromatism in anurans, in which they recognize two kinds. Dynamic dichromatism occurs when males undergo a temporary color change during the breeding system. This ranges from subtle to dramatic, and is fairly widespread phylogenetically. Ontogenetic dichromatism involves changes in one sex, but not the other, related to ontogeny; only a few studies have documented the biological bases of such change. This study is the first to attempt a comprehensive, phylogenetically informed, analysis of these phenomena. Read more in AmphibiaWeb. (DBW)

    • November 5, 2012: The pipid frogs, comprised of four genera (Pipa, Hymenochirus, Silurana and Xenopus), represent one of the oldest living lineages of all amphibians and yet the history of their diversification (i.e. their evolutionary relationships) has been contested for many years. These frogs have a relatively rich fossil record and includes living members currently span across widely separated continents (Africa, North America and South America) with well-known geologic separation dates (the continents once were connected). Yet there is considerable disagreement about pipid frog evolutionary relationships. A new paper by Bewick et al (2012) used high throughput sequencing and public databases to generate a large phylogenomic dataset to estimate evolutionary relationships. They found strong evidence showing West African Hymenochirus is more closely related to the South American Pipa than to the other African pipid species, Xenopus and Silurana. (VV)

    • October 29, 2012: The frog Nasikabatrachus sahyadrensis represents an ancient lineage endemic to the Western Ghats of India. Described almost ten years ago, much remains unknown of the natural history of this unusual species. In a pair of Zootaxa papers, Zachariah et al. (2012) and Raj et al. (2012) described in detail the reproductive biology and tadpole of Nasikabatrachus. Females find males calling from individual burrows along streams, and mating and egg-laying occurs mostly in small pools alongside torrential streams. Large numbers of eggs are laid and fertilized (>1000), and within a week tadpoles are fully formed. Unusual for a fossorial frog, the tadpoles are specialized for living in fast moving streams, having a stream-lined appearance and a large suctorial mouth used for rasping rock surfaces, including outside of the water and well into metamorphosis. Zachariah et al. (2012) add new distributional records and stress that recent irregularities in monsoon rainfall may put this species at risk because of its larval biology. (DB)

    • October 22,2012: Field surveys revealing the presence of either declines or disease are still relatively uncommon for African countries. Gower et al. (2012) present the first surveys for the chytrid fungus Bd at montane sites in Ethiopia, including for the Bale Mountains which are in important region of endemism for amphibians. Based on surveys in 2008 and 2009, more than 40% of examined individuals were infected with Bd, though largely with low intensity infections. Prevalence tended to be higher in species with aquatic larvae, and in two such species (Phrynobatrachus minutus and Leptopelis gramineus), prevalence was greater than 60%. While no mortality events were observed related to Bd, declines in Ethiopian amphibians are apparent and the role of disease in these declines remains uncertain. (DB)

    • October 15, 2012: Congratulations to John Gurdon of Cambridge University, UK, who has been awarded the Nobel Prize in Physiology or Medicine for his research, first published in 1962, which paved the way for modern stem cell research. He tested the hypothesis that cells retain the potential to return to pluripotency, the capability to differentiate into any cell type, by replacing the cell nucleus of a frog's egg cell with a nucleus from a mature, specialized cell derived from the intestine of a tadpole. The egg developed into a fully functional, cloned tadpole. Throughout his long and prolific career the experimental organism of choice in Gurdon's lab has been the African Clawed Frog, Xenopus laevis. Gurdon shares the prize with Shinya Yamanaka, Kyoto University and University of California, San Francisco, who does not work with frogs.

    • October 8. 2012: Tiny animals have been postulated to differ from large ones in traits related to overall evolutionary diversification. Wollenberg et al. (2011) postulated a "microendemic phenotype" or MEP for frogs, in which the combination of small body size and small range size should result in increased rates of speciation in clades with these characteristics. The Malagasy-endemic frog clade Mantellidae has mostly small species, the smallest of which is 13 mm (maximum male body size). Using an extensive phylogeny and correlation analysis of 257 species (including candidate species) of the Malagasy-endemic Mantellidae, they supported the existence of a MEP. They also hypothesized that clades with the microendemic phenotype (small body size and small range) would have greater species richness, but were unable to support this hypothesis. However, they found that small size alone tends to predict species richness. They conclude that, contrary to expectations of increased diversification, the combination of small body size and small range size results in a slow-down in rate of diversification, as would be expected in the later stages of adaptive radiation. (DC)

    • October 1, 2012: September 26, 1912, was the birthday of Professor-Emeritus Hobart Muir Smith of the University of Colorado, Boulder, who reached 100 years of age last week. We congratulate Hobart and celebrate his spectacular scientific productivity, which includes about 1500 papers and books. While best known for work with reptiles, Hobart made significant discoveries on amphibians during his long field trip to Mexico starting in 1932. Hobart devoted his life to the herpetology of Mexico. He named many species of amphibians, and two salamanders (including Thorius smithi above) and two frogs named for him are currently recognized. AmphibiaWeb salutes Hobart Smith and sends him our congratulations and very best wishes. See the tribute video that researchers at UNAM (National Autonomous University of Mexico) created in Spanish.

    • September 24, 2012: The cause for some amphibian declines has been linked to global climate change, most recently by Lowe (2012) in the stream breeding amphibian Gyrinophilus porphyriticus. Between 1999 and 2010, Lowe found a significant decline in abundance of G. porphyriticus adults, with no trends found in larval abundance. Annual precipitation is predicted to increase in Northeast USA due to climate change, and adult G. porphyriticus are negatively correlated with higher annual precipitation. Survival during metamorphosis also declined dramatically during this time. These results suggest that increasing precipitation is causing a decline in adults and metamorphosing larvae, which could lead to local extirpation of this species. It is possible that metamorphosing individuals are dying during spring and fall floods, which have increased in volume and frequency in the past 12 years. There is a critical need to collect population data on more stream-breeding amphibian species. (CS)

    • September 17, 2012: For many little known amphibians, museum collections are the only form of information on them. These historic data can be put to use with modern observational records as Akmentins et al (2011) show for the three Gastrotheca species of conservation concern in Argentina. They used probabilistic modeling with museum records and recent rediscovery data on Gastrotheca gracilis to test the assumption that G. gracilis, G. christinani and G. chrysosticta, all endemic to the southern Andean Yungas montane forest, still survive. Their predictions are that while likely still extant they are in severe decline and should be moved to the Critically Endangered listing. (MK)

    • September 10, 2012: Understanding the disease dynamics of occurrence and outbreak in space and time is an important goal of studying the deadly chytridiomycosis and its causative agent, the fungus Batrachochytrium dendrobatidis (Bd). A recent study (Velo-Antón et al 2012) used population genetics techniques on Bd from western North America through Central America and found that Bd conforms to the Spreading Pathogen Hypothesis where pandemics occur after exposure to naive populations. It is clear Bd is a novel pathogen that spread southward from North to Central America and that future conservation efforts should include both research on the genetic variation of its pathogenicity as well as public education and trade restrictions to curb its spread. (MK)

    • September 3, 2012: Exploiting competitive mechanisms to control an invasive species. Cane toads, Rhinella marina, are invasive in Australia, where they are rapidly advancing into new terrain. Their tadpoles consume eggs of co-occurring species and impact native species populations greatly. Crossland et al. (2012) show that toxins (mainly bufadienolides) extracted from cane toad eggs serve as a "cannibal attractant" when used to bait funnel traps, which caught tens of thousands of cane toad tadpoles. Because native frogs do not produce bufadienolides and are not attracted to them, baited traps can be used in a strategy to control cane toad populations. (DW)

    • August 27, 2012: No other amphibian has the panoply of bright colors as those found in populations of Oophaga pumilio, the Strawberry Dart frog: red, blue, green, yellow, arranged in a diversity of spotted, blotched, and solid patterns. Such variation is thought to be due to sexual selection, i.e., females choose certain mates over others. Thus the inheritance of certain traits is not random. In previous lab studies of one population with only red and yellow individuals, females preferred males of similar coloration. But what do animals do in nature? Richards-Zawacki et al. (2012) used a more direct method of identifying successful matings- pedigree analysis. Using genetic analysis of parentage, they determined that in nature yellow females were less choosy; they mated with red or yellow males more or less equally. However, red females were very choosy and mated only with their own morph. Many reasons (visual sensitivity, the effort that yellow females may use to find mates, etc.) might explain the differences in lab and field behavior. But importantly, the study emphasizes the need for multiple approaches to the same biological question. (DCC)

    • August 20, 2012: A new study based on resurveys in the Great Smoky Mountains National Park (southern Appalachian Mountains) finds no clear answers for the almost 50- year widespread decline in plethodontid salamander populations. In general, Caruso and Lips (2012) found declines not associated with localities but with certain Plethodon species, such as P. glutinosus and P. teyahalee. Normally associated with such widespread amphibian declines, chytridiomycosis was ruled out after they found only one out of 665 salamanders with Bd. Instead they found mixed correlation with climate change and morphological differences among salamander species which declined and those which did not or even increased in populations. Amphibian declines in the eastern US are poorly studied and thus remain enigmatic. This study is important to understanding declines in the heart of diversification for the Plethodontidae family. (MK)

    • August 13, 2012: One of the new species of treefrogs has been named for an equally colorful personage, His Royal Highness Charles, Prince of Wales. Dr. Luis Coloma, Director of the Centro Jambatu in Ecuador, and his colleagues have named a colorful frog from northern Ecuador ( Coloma et al. 2012). The patronym Hyloscirtus princecharlesi honors the Prince for his efforts in preventing deforestation in tropical habitats crucial to the survival of millions of species. The species is one of a hidden lineage of frogs dwelling in the high Andes, unknown until museum expeditions first entered these forests about 40 years ago. The Prince Charles Stream Treefrog will likely stand as a beacon for the worldwide amphibian conservation effort. The announcement of the new species took place at a meeting between Dr. Coloma and Prince Charles at Highgrove House, an exchange facilitated by Amphibian Ark (Watch the video here). (DCC)

    • August 6, 2012: Another milestone: The 25,000th photograph posted on AmphibiaWeb is of a recently described species, Bolitoglossa aureogularis, taken by Roney Samaniego and Eduardo Boza-Oviedo. The photograph is of the adult female holotype, found in 2007 near the crest of the Trans-Talamancan trail in a remote part of the Cordillera de Talamanca, Costa Rica (Boza-Oviedo et al., Zootaxa 2012). The species represents a previously unrecognized clade that also includes the recently named Bolitoglossa robinsoni. Thanks to Photographer Eduardo Boza-Oviedo, who has contributed 122 photographs of 52 species of amphibians to AmphibiaWeb.

    • July 30, 2012: The total number of amphibian species reached 7,000 today. The 7000th known amphibian is a new glassfrog from Peru, Centrolene sabini (Catenazzi et al 2012), which was discovered at high elevations in Manu National Park, Peru. Glassfrogs have increased from 65 in 1985 to 152 known today, illustrating the paradoxical phenomenon of amphibian discovery during a time of great concern for amphibians. In June 2012, IUCN reported 41% of amphibian species at risk of extinction. Yet, the number of known amphibian species has increased dramatically, from 4,013 in 1985 to 7,000. Enjoy AmphibiaWeb's new song in celebration of the 7000th species!

    • July 23, 2012: Many factors affect the success of non-native species introductions. A new study by Rago, While and Uller (2012) found that similarity between native climate and introduced locality climate have more to do with amphibian introduction success than species traits, such as phylogeny, ecology and life history. This contrasts with other recent work showing that species traits were major factors for introduction of non-native species. Using life history data and geographic range size from multiple sources, including AmphibiaWeb, IUCN, primary literature and field guides, Rago et al. analyzed establishment success. Climatic similarity between the native range and introduced locality was the strongest predictor for establishment success. Pathways of introduction were also a strong predictor, with intentional introductions being more likely to succeed than non-intentional ones. This study shows that human-mediated introductions and movement of species in similar climatic envelopes are major factors affecting success of amphibian introductions. (CS)

    • July 16, 2012: The New York Times reports that "Frog Juice" is being used secretly and illegally in the US horse racing industry as a pain suppressant, intended to enhance performance. It also makes the horses feel more excitable and euphoric. The active agent is dermorphin, an opioid first isolated from the skin of Phyllomedusa sauvagii and probably present in related species. It is well known that amphibian skin is a veritable pharmacopoeia, producing diverse alkaloids, opioids and other secondary compounds. Dermorphin is reported to be 40 time more effective than morphine in reducing pain, but side effects are less well known in either equine or human subjects. (DW)

    • July 9, 2012: The timing of egg hatching and development is known to be highly adaptive and thus under selective pressure. Many studies have shown the effect of the timing of early stages has on fitness. Recently Hopkins et al. (2012) showed a high level of variability of these traits in the Rough-skinned newt, Taricha granulosa, which is independent from the habitat temperature. Moreover the values of the traits and the degree of differences between the study females' lineages could not be explained by morphological traits of mothers nor the eggs. They suggest that the variation necessary for selection to work on is present at the earliest of life history in this amphibian, which seems especially important given the presence of seasonal predators such as dragonfly nymphs. (JW)

    • July 2, 2012: In June, the US Environmental Protection Agency's Scientific Advisory Committee met to conduct an ecological risk assessment of Atrazine, an herbicide that is associated with a wide variety of problems in amphibians. One of the most notorious studies on Atrazine, an estrogen disruptor, was linked with amphibian sex reversal when applied to amphibian larvae in ecologically relevant doses (Hayes 2002). Since that publication in 2002, there have been many calls for the ban of Atrazine use in the United States (it is already banned in the European Union). The EPA will be reviewing scientific research on the effects of Atrazine on aquatic communities, including amphibians, in anticipation of the upcoming registration review, set to take place in 2013. (Jamie Voyle)

    • June 25, 2012: A newly published study (Rosenblum et al. 2012) reveals that frogs as phylogenetically diverse as ranids and pipids display a shared genetic response to infection by the chytrid fungus Batrachochytrium dendrobatidis. The authors characterized transcriptomes of Rana muscosa and Rana sierrae in experiments that controlled for Bd infection, and compared the results with comparable studies of Xenopus tropicalis. The infected frogs show massive disruption of skin function and no robust immune response. (DW)

    • June 17, 2012: Just in time for Father's Day in the US, UK, and elsewhere. Male parental care of eggs and young is unusual in frogs, but evidence continues to build that a number of members of the microhylid subfamily Astylosterninae, especially Cophixalus, Austerochaperina and Liophryne from Australia and New Guinea, have male parental care of terrestrial, direct developing eggs (Hoskin 2004). Males of some astylosternines even transport newly hatched froglets (Bickford 2002). AmphibiaWeb lists 266 astylosternines, and more are discovered every year. A recent discovery (Hoskin 2012) is Cophixalus hinchenbrookensis, known only from Hinchinbrook Island off the central coast of Queensland, in which males guard eggs. All of these frogs eat ants and it has been suggested that ants might be the major egg predators. (DW)

    • June 11, 2012: An association between rates of metabolism and molecular evolution is not a new idea. Yet, previous work on ectotherms has not supported an association between rates of molecular evolution and resting metabolic rate. Using data for poison frogs in the family Dendrobatidae, Santos (2012) combines diverse information for resting and active metabolic rates, phylogenetic relationships, body mass, fecundity, and rates of evolution for both mitochondrial and nuclear genes. His analysis suggests a strong positive relationship between rates of active metabolism and molecular evolution and hint at a possible mechanism for this relationship based on an increase of reactive oxygen species during active exercise. (DB)

    • June 4, 2012: Phrynobatrachus is a widespread African genus of 85 currently recognized ranoid frog species usually placed in their own family. Zimkus et al. (2012) conducted a phylogenetic analysis of a large number of species of Phrynobatrachus to determine correlates of miniaturization and terrestriality, both represented in numerous species. They hypothesized that miniaturization is correlated with terrestriality, but such proved not to be the case. Instead, while each has evolved multiple times, the two trends are decoupled. Thus neither trait constitutes a key innovation for an adaptive radiation associated with the diversification of this taxon. (DW)

    • May 28, 2012: More than half of the truly diminutive frogs (46 species defined as less than 15 mm snout-vent length(svl)) have been described since 2000. Annandale described Pseudophilautus semiruber, a diminutive upland frog, in 1913 but has not been seen for a century until recently. Its rediscovery from the Agra-Bopath forest at 1,750 m a.s.l. led to research by Meegaskumbura et al. (2012) showing that it and the distantly related P. tanu are the smallest members of Pseudophilautus. P. semiruber (12-13.4 mm snout to vent) is the sister taxon of the genetically distinct (4% different in 16s mtDNA sequences) P. simba, which is only slightly larger (12.6-15.6 mm svl). (DW)

    • May 21, 2012: Salerno et al. (2012) found that the ancient tepui summits in South America harbor young, rather than old, lineages of frogs. The tepuis (flat-top mountains) of South America, known as 'sky islands', were the inspiration for Sir Arthur Conan Doyle's novel The Lost World. These are ancient remnants of the Precambrian Guianan Shield plateau and were formed 70-90 mya. Because of their age, it was thought that the fauna of the tepuis may also be very old, and the tepuis may have served as a refuge for these species. But Salerno (et al. 2012) found that treefrogs of the genus Tepuihyla climbed up the 1000-meter tepuis from the lowlands within the last 2-5 mya. Currently there is no empirical evidence for the 'Lost World' hypothesis. (CS)

    • May 15, 2012: Carlos Vasquez Almazan, a Guatemalan amphibian expert, is one of this year's Whitley Fund for Nature Awards winners. Carlos created Guatemala's first network of protected areas for endangered amphibians, including critical habitat for Duellmanohyla soralia, endemic to the Sierra Caral and Sierra Merendon along the Honduras-Guatemala border. View the video on Carlos and Guatemala narrated by Sir David Attenborough.

    • May 7, 2012: The evolutionary effects of contemporary human construction are not well known. Steven P. Brady (2012) has shown that roads could be a novel agent of selection on Ambystoma maculatum in a human-altered landscape. While negative ecological effects are evident, he addresses potential responses of local populations to the harsher roadside conditions, which would lead to differential survival ability across the whole population. After a translocating experiment, he found that roadside living sub-populations were more able to survive than those which live away from the road. Moreover his study suggests a role for a genetic component in explaining the local adaptation, offering the hope that vertebrates may adapt to anthropogenic disturbance on contemporary timescales and across small spatial scales. (JW)

    • April 30, 2012: Chytridiomycosis, the amphibian disease caused by the fungal pathogen Bd, has decimated numerous amphibian species around the world. Investigation of Bd's deadly effects have so far primarily been done in captivity, with lab-cultured strains that may have lost some virulence. A new PLoS ONE paper by Voyles et al. (2012) is the first to examine blood chemistry of infected frogs in the wild during an outbreak of chytridiomycosis. The results show that electrolyte depletion (sodium and potassium) for heavily infected mountain yellow-legged frogs in the wild is even more extensive than studies done in captivity have suggested, and is accompanied by severe dehydration despite the frogs' aquatic environment. See also the NSF commentary. (KW)

    • April 23, 2012: Pipidae is a thoroughly researched frog group; Xenopus laevis is a model species and Silurana tropicalis is the single frog with a complete sequenced genome. Morphological analyses (including fossils) and earlier single gene analyses placed Pipa + Hymenochirus (Pipinae) in a clade with Xenopus + Silurana (Xenopodinae) as its sister clade. Because Pipa is South American and Hymenochirus is African, this phylogeny supports an African origin (African Root). Recent analyses of multiple genes place African genera in one clade in opposition to Pipa. Here, the origin of Pipidae cannot be more specific than Gondwana (Gondwanan Root). Bewick et al. 2011 using more than 100 genes analyzed with newer coalescent methods, found strongest support for the African Root Hypothesis, validating earlier phylogenies. Nonetheless, the authors identify general difficulties: large ancestral population sizes, ancient divergence times, and failure to identify duplicated genes (paralogs). (DCC)

    • April 16, 2012: The Indian subcontinent has long been recognized as an important center of biodiversity: India and Sri Lanka together have about 450 species of amphibians, and India's Western Ghats is well known as a biodiversity hotspot (for an interesting account of Indian herpetologists at work in the Western Ghats see The Economist article). Now Kamei, Biju, and colleagues announce a new amphibian hotspot, the region where the recognized Himalayan and Indo-Burma hotspots make contact in northeastern India and northern Myanmar. The caecilian Herpele fulleri is shown to differ greatly from other herpelids, part of a previously undetected clade whose estimated divergence time from the herpelids is so ancient (possibly dating back to the beginning of the Cretaceous) that they designate the clade a new genus (Chikila) and family (Chikilidae). The other members of the new clade, all from the same general region, are at present unnamed. The authors suspect the region contains more 'hidden treasures'. (DW & MW)

    • April 9, 2012: A new paper by Mokhatla and colleagues in Diversity and Distributions (2012) assessed anthropogenic threats on South African amphibian breeding areas. Terrestrial frogs were found more often than chance in breeding areas where anthropogenic land changes or high numbers of invasive plants occur. South-central South Africa is the only region where terrestrial frogs coincided with protected areas. The majority of regions where stream-breeding frogs occurred coincided with non-native plants and other anthropogenic effects. Breeding areas for both aquatic and terrestrial frogs in the southwestern Cape are most congruent with multiple anthropogenic threats. This study showed that the presence of non-native plants and anthropogenic-changed landscapes were important factors for management of breeding amphibians. Also, it highlighted areas where terrestrial breeding amphibians are not well represented in current conservation networks. (CS)

    • April 2, 2012: Invasive cane toads (Bufo marinus) in northwestern Australia have proven lethal to many native animals, which eat the toxic amphibian and are not adapted to its secretions. One such affected species is the omnivorous reptile Tiliqua scincoides, the bluetongue skink. A University of Sydney study, however, indicates that another invasive species, a plant native to Madagascar named mother-of-millions (genus Bryophyllum), may have helped some skink populations to develop resistance to the cane toad's deadly toxins. The plant produces bufadienolide toxins similar to that of the cane toad (a result of convergent evolution), and both species are readily ingested by bluetongue skinks. Skinks from regions with introduced mother-of-million showed a higher resistance to bufadienolides than skinks from regions without the plant. Such preadaptation may have a positive impact on the persistence of bluetongue skinks, and other omnivorous Australian species in the face of the introduced cane toads. (John Cavagnaro)

    • March 26, 2012: How many species of Amphibians ARE there? With nearly 7,000 species described, one might think we are reaching a decisive answer. However, in many parts of the world, we are just coming to understand that herpetologists have overlooked cryptic species. Funk and colleagues report finding that species richness in Ecuador, which may have more species of amphibians per unit area than any other country on earth, has been severely underestimated. For example, two currently recognized species of Engystomops are shown to be from five to seven species, and two species of Hypsiboas are six to nine. Clearly, amphibian taxonomists still have much work ahead of them. (DW)

    • March 19, 2012: Although most new species of amphibians are being discovered in remote corners of the tropics, sometimes there are surprises: a new frog species has been reported in New York City (and surrounding counties). The as-yet-unnamed species of leopard frog resembles the southern leopard frog, Rana sphenocephala, but is clearly distinct from other local leopard frog species (R. sphenocephala, R. pipiens, R. palustris) both genetically and by its call, and has a restricted range. This new discovery highlights the importance of urban areas as well as pristine habitat in conservation of biodiversity. See both the paper by Newman et al. (2012) in Molecular Phylogenetics and Evolution, and the NYTimes and NSF perspectives. (KW)

    • March 12, 2012: AmphibiaWeb has a new taxonomy for families! You can read more about AmphibiaWeb Taxonomy 2.0 on our updated Taxonomy page. Our entire "Browse species lists" has been updated to reflect the new family-level organization. AmphibiaWeb 2.0 is the result of in-depth studies of the current literature dealing with amphibian phylogenetics and taxonomy by a multi-institutional working group of taxonomic experts. From time to time, the taxonomy will be updated, as warranted, based on new analyses and publications. Comments are welcomed. We also solicit assistance in writing family and species accounts from specialists. We invite you to contact us!

    • March 5,2012: Despite amphibian species bearing the brunt of declines among most vertebrate groups (over 40% of known amphibians are in decline), they have garnered the least attention in terms of funding and capacity building to address this crisis. Gratwicke, Lovejoy, and Wildt (2012) quantify this disparity by comparing the funding per species listed under the US Endangered Species Act with NatureServe's endangerment status, and find that listed US amphibians receive only a quarter of funding that other listed vertebrates do. They also reveal a larger disparity as 82% of amphibians that are listed at risk by NatureServe remain unlisted by the US, where many species are as threatened as their tropical brethren. (MK)

    • February 27, 2012: Invasive species often have surprising effects on their adopted environment, be it by direct interaction with other species or by altering the habitat. In a study by Watling et al, the effects of an invasive plant's phytochemicals on some species of amphibians have been reported. In one common species, the American toad, the presence of the introduced bush honeysuckle's (Lonicera maackii) allelopathic compounds in the water decreases tadpole survival. In other amphibian species, the presence of the plant chemicals alters the behavior of the tadpoles, increasing the number of trips to the surface, which may be a way to counteract the toxic effects of the plant products. (JW)

    • February 20, 2012: The most diverse salamander clade in the Western US, Batrachoseps has recently grown in number to 22 recognized species, with the recent addition of B. altasierrae and B. bramei (Jockusch et al 2012). These two new species are found in the rugged southern Sierra Nevada of California, where now six species of Batrachoseps are known, highlighting this region as not only one of general high vertebrate endemism but also a center of Batrachoseps diversification. (MK)

    • February 13, 2012: California Protects Sierra and Southern California Mountain Yellow-legged frogs under State Endangered Species Act. Just a few decades ago, mountain yellow-legged frogs (comprised of two closely related species, the Sierra Nevada yellow-legged frog, and the southern mountain yellow-legged frog) were very abundant throughout their range in California and parts of Nevada, but declined rapidly. Widespread planting of nonnative trout from airplanes in high-elevation lakes has been a primary cause of the species' decline. Introduced trout eat tadpoles and juvenile frogs and change the food web of the aquatic ecosystems on which the native frogs depend. Since 2000, agencies began restoring frog populations by removing nonnative trout from some high Sierra Nevada lakes; however, an emerging fungal pathogen ("chytrid fungus") has caused widespread mass die offs and more than half of the remaining populations identified in 1995 have disappeared. US Fish & Wildlife will rule on their status in October 2012. (VV)

    • February 6, 2012: One of the most enigmatic amphibians is the lungless caecilian Atretochoana eiselti. Edward Taylor described this species in 1968, based on an old specimen in the Vienna Museum, said to be from South America. Wilkinson and Nussbaum (1997) studied the type in great detail and described its lunglessness and associated features. Authors conjectured that the species must be aquatic; the only other known lungless caecilian is the tiny terrestrial Caecilita iwokramae. Now, Hoogmoed et al. (2011-PDF) report rediscovery of the species in Brazil, from Baía de Marajó, a tidal zone near Belém, but also from the geographically remote (2000 km) upper reaches of the Madeira River in Rondônia. The largest specimen is a meter long. How this species survives in such varied environments and how respiration takes place remain to be discovered. (DW)

    • January 30, 2012: Froglog, started 20 years ago by the Declining Amphibian Populations Task Force (DAPTF) and now published by the Amphibian Specialist Group, celebrates its 100th issue, 69 pages of amphibian research and conservation news from around the world. FrogLog continues with special regional focus issues, the latest on South American herpetology. Read the latest FrogLog directly on AmphibiaWeb! (KW)

    • January 23, 2012: Chytridiomycosis is thought of as exclusively an amphibian disease. However, it is clear that the causative fungus Batrachochytrium dendrobatidis (Bd) can persist in the environment and other non-amphibian species may serve as vectors. A recent paper by Kilburn et al. suggests that reptiles may spread the disease by having the fungus on their skin. The study in Panama surveyed 21 species of snakes and lizards and found Bd in varying intensities and was positively correlated with infection rates among co-occurring frog species. Whether reptiles simply act as vectors or reservoirs and are not likewise infected remains to be shown. (JW)

    • January 20, 2012: IN MEMORIAM: Joseph T. Collins, founder of the Center for North American Herpetology website, died on January 14, 2012, at the age of 72. He was one of the founders of the Ohio Herpetological Society, which became the Society for the Study of Amphibians and Reptiles, and was associated with the University of Kansas for many years. Roger Conant invited Collins to join him as a coauthor of the third edition of the Field Guide to Eastern Reptiles and Amphibians in the Peterson Field Guide series. Collins wrote extensively about the Kansas herpetofauna and long advocated for increased public awareness of amphibian and reptiles. (DW)

    • January 16, 2012: AmphibiaWeb added 149 species of amphibians to our database in 2011, the fewest since we began keeping track in 2004. However, 2010 was a big year, with 205 species added, and the passage of a year is a pretty arbitrary stopping point. The mean number since 2004 is 184. Most of the additions are new discoveries, but some are subdivisions of taxa stimulated by new discoveries. An example of this pattern is the new monograph in Zootaxa of the megophryid frog Leptolalax (Lalos) by Ohler et al. . New discoveries led to new analyses that showed formerly widespread species to be non-monophyletic, which in turn led to descriptions of truly new species and the resurrection of others from synonymy. (DW)

    • January 1, 2012: Happy New Year's to all our users and contributors! As a community of amphibian enthusiasts, researchers and students, you have contributed almost 24,000 photos of 3,631 different amphibian species, and 2,810 species accounts out of the 6,909 total species of amphibians that we tally here at AmphibiaWeb. We sincerely thank you for all your contributions and for using AmphibiaWeb as your resource for information on amphibians, their biology. and their decline status. We look forward to an exciting 2012 with many new developments on tap, including updated taxonomy, new taxonomy tools, enhanced maps, and improving mobility with our iPhone app, which you can treat yourself to now (download from iTunes). Stay in touch with AmphibiaWeb as we move forward into 2012!


    back to News by Year

    • December 19,2011: The task to survey and monitor often cryptic species in the world's aquatic systems such as ponds, streams, lakes, and wetlands is a daunting challenge. Biologists now have a powerful new tool which starts with just a shot-glass size sample of pond water. A Danish research team has shown that DNA traces in the water sample can be amplified and thus contain evidence of an entire aquatic fauna. The proof-of-concept study focused on species as diverse as the Eurasian otter, Weather loach (fish), Spadefoot toad (Pelobates fuscus), Great crested newt (Triturus cristatus), Large white-faced darter (dragonfly), and the tadpole shrimp. This may be the future of biodiversity monitoring, using DNA traces in the environment to discover and keep track of threatened wildlife. (MK)

    • December 12, 2011: In a November 2011 Letter to Nature, Hof, Araújo, Jetz and Wahbek report that multiple threats from pathogens, land-use and global climate change affect amphibian populations, and that together, these additive, multiple effects will likely cause accelerated declines and extinctions in the 21st century. Using current distributions of amphibians and the fungus pathogen chytridiomycosis with future climate scenarios, the authors projected that areas most affected by chytridiomycosis would have little spatial overlap with areas most affected by global climate change and land-use change. Areas most affected by global climate change also have high land-use change impacts. The latter occurs in Africa, parts of northern South America and the Andes. Overall, the areas where the richest amphibian faunas occur will be disproportionately more affected by one or multiple threats than areas with low amphibian richness. (CS)

    • December 5, 2011: Where to search for missing amphibian species? Garcia-Rodriguez et al. recently provide a method that could help to find populations of such species, especially in countries that have undergone a severe decline in amphibian species, both in abundance and distribution, such as Costa Rica. By creating consensus climatic niche maps of the historic range of endangered species and their relictual (i.e. persistent) distributions, they considered an array of factors, such as conservation areas, potential presence of pathogens, collecting effort, annual precipitation, among others, resulting in geographic predictions that have matched well with recent discoveries of relictual populations. Their method could be influential on decision-making about the location of future protected areas, as well as where to target limited funds on the discovery of endangered species. (JW)

    • November 28, 2011: Rediscovery of the Hula Painted Frog (Discoglossus nigriventer) in northern Israel is a great and welcomed surprise. The species was declared extinct in 1996 and had not been observed since 1955. The only preserved specimens are the holotype, collected in 1940, a second specimen, collected in 1955, and two tadpoles. The initial discovery of the species included two specimens but the holotype ate its companion in captivity! On November 15, 2011, an adult was found by Yoram Malka, a warden at the Hula Nature Reserve. It was swabbed for future DNA studies and returned to its habitat. Discoglossus is otherwise restricted to southwestern Europe and northwestern Africa. The 6,000 hectare Hula wetlands region, an important resting area for migrating birds, was largely drained for malaria control in the 1950s, but happily the species survived in a 320 hectare remnant that became Israel’s first nature reserve in 1964. The discovery received great media attention, as is appropriate for an event heralded as biologically equivalent to the discovery of the Dead Sea Scrolls! (DW)

    • November 21, 2011: AmphibiaWeb has gone mobile! Good news for iPhone users as AmphibiaWeb now has a mobile app in beta, available for downloading from iTunes. Written by an enterprising AmphibiaWeb volunteer, it allows you to search for amphibian species by name or geography including your location and then view species descriptions, photos, and listen to calls. We are still adding functionality and refining the checklist feature that will generate a list of expected species by your location, so stay tuned for updates. Please let us know what you think; your feedback is valuable.

    • November 14, 2011: New studies of fungal genetics have implications for amphibians. Rhys Farrer et al. report multiple deeply diverged lineages within the chytrid fungus Batrachochytrium dendrobatidis (Bd), which causes chytridiomycosis in amphibians. A specific hypervirulent lineage is associated with disease outbreaks on multiple continents. Perhaps human-mediated mixing of lineages of different geographic origin gave rise to the hypervirulent lineage. A second study by Suzanne Joneson et al. reports the complete genome of a related chytrid and compares it with Bd and 19 other fungal genomes, finding 1,974 Bd specific genes. Among these are a protease gene family that has emerged recently and may have implications for Bd pathogenicity. Probing genetic diversity of Bd and related fungi will likely be an important future direction for understanding the origin, spread, and pathogenicity of Bd. (DB & DW)

    • November 7, 2011: A major revision of South American poison frogs discusses controversies over the taxonomy of Dendrobates (in the broad sense, as previously on AmphibiaWeb) and supports division of the genus into seven genera, including a new genus Andinobates. The monograph by J.L. Brown , E. Twomey, A. Amézquita, M.B. De Souza, J.P. Caldwell, S. Lötters, R. Von May, P.R. Melo-Sampaio, D. Mejía-Vargas, P. Perez-Peña, M. Pepper, E.H. Poelman, M. Sanchez-Rodriguez, and K. Summers (“A taxonomic revision of the Neotropical poison frog genus Ranitomeya (Amphibia: Dendrobatidae)” 2011 Zootaxa 3083: 1-120) is profusely illustrated in color and includes extensive analyses of new and existing molecular data and a great deal of detail concerning the biology of these diminutive and spectacular species. (DW)

    • October 31, 2011: An extensive new phylogeny has been reconstructed for amphibians, based on over 2,800 species representing 86% of amphibian genera (Pyron and Wiens 2011). In comparison, the largest previous study on amphibian phylogenetics (Frost et al. 2006) used 522 species and data from less than half as many genes. Pyron and Wiens' supermatrix analysis supports many previous conclusions on amphibian familial taxonomy but also shows that some currently recognized families are non-monophyletic and recognizes a number of new families. See the latest issue of Molecular Phylogenetics and Evolution (November 2011) for more details. (KW)

    • October 24, 2011: Many studies using future climate models have shown the potential, and often severe, impact on species distributions. A recent one in Ecology Letters ( Early and Sax 2011) took a closer look at future climate projections specifically by tracking 15 western North American amphibian species’ distributions as predicted by future climate niche models and the likely corridors they would have to travel by 2100 to maintain their current environmental conditions. They found that even if future distributions were large, the intermediary decades of climactic fluctuations may still imperil species if range shifts are not continuous or too brief for low vagility species like amphibians. The authors raise important considerations for conservation efforts. (MK)

    • October 17, 2011: Female Strawberry Poison frogs, Dendrobates pumilio, can be aggressive to each other, and a new study by Meuche, Linsenmair, and Pröhl (2011) explains why. In the Hitoy Cerere Biological Reserve, Costa Rica, female frogs defend a “core area” against other intruding females. The core area was defined as 50% of observation points within the female’s home range. Females did not defend mates, oviposition or tadpole-rearing sites but seem to be defending spatially-limited food resources. Over 54% of all female-on-female agonistic behavior took place within individuals’ core areas, and most female feeding also occurred within this “core”. Aggressive behavior included jumping, clasping or wrestling. Defense of food is important to females both for survival and because food intake influences egg size. (CS)

    • October 10, 2011: Do you know about the Bolivian Amphibian Initiative? This project focuses on both monitoring and conservation of Bolivia’s endangered amphibian species, notably in the high Andes. The Bolivian Amphibian Initiative provides training and community outreach as well as research opportunities and conservation actions such as a captive breeding program. This landlocked country holds at last count 240 amphibian species, a good fraction of them being endemic and threatened or endangered by several factors while many are simply data deficient. A lot of areas are poorly documented and monitoring is highly needed. This project, bringing together local people, park guards and biologists, is a remarkable initiative that addresses much needed attention and focus on Bolivian amphibian fauna. (JW)

    • October 3, 2011: In a recent study of wild frog populations, Savage and Zamudio demonstrate a genetic basis to survival following infection with the chytrid fungus Batrachochytrium dendrobatidis (Bd). When looking across the populations in their study, the authors found that having more genetic variation in immune (MHC) genes was positively related to an individual’s ability to survive Bd infection. Within populations, one specific genetic variant was related to increased survival of individuals. Importantly, this one variant that confers resistance was found to be under positive selection. This demonstrates that natural populations of amphibians can evolve resistance to Bd. (DB)

    • September 26, 2011: The Western Ghats lines the entire western front of India, forming a mountainous rain shadow, and consequently, a recognized biodiversity hotspot. Even so, the full extent of amphibian biodiversity may have just started to be fully known as suggested by the 24 new amphibian species formally described in 2011 so far, including a new caecilian, one Polypedates frog, nine Raorchestes frogs, one Leptobrachium frog, and now S.D. Biju and colleagues reveal 12 new species of Nyctibatrachus, also known as Night frogs. In a taxonomic revision of the genus, they also report the rediscovery of three species thought to be extinct, a new morphological structure to diagnose this group, as well as new courtship and egg attendance behaviour for several of these species. In all, the genus Nyctibatrachus is recognised with 28 species in a paper that lays the groundwork for more detailed research for this genus and amphibians of the Ghats. (MK)

    • September 19, 2011: Barbourula kalimantanensis, the only frog known to lack lungs, lives in cool, clear, well-aerated, mainly headwater streams in mountains along the border of West and Central Kalimantan in a small area in the west-central island of Borneo. Strictly aquatic, its only relative is a congener restricted to three islands in the western Philippines. It is currently listed as Endangered by IUCN. Rachmayuningtyas et al. report new discoveries that extend the range and disclose some genetic diversification. Habitat is severely limited but the range now extends over an area of more than 5,000 sq km so the authors propose reclassifying the species as Vulnerable. They also propose that the species be treated as a flagship species for Bukit Baka Bukit Raya National Park, where several populations occur. Nevertheless, the severe habitat requirements of the species means that vigilance is necessary to prevent logging and stream degradation. (DW)

    • September 12, 2011: The severe wildfires in Texas has affected millions of people and wildlife in the state. The endangered Houston Toad, Bufo houstonensis, will likely suffer a severe setback as a result of fires in Bastrop County, near Austin, Texas. The area has had a combination of >75 days in the triple digits and virtually no rain in several months. The loblolly pine forest encompassing Bastrop State Park became a tinder box waiting to explode, and it did so during the past week of September. All but 50-100 acres of the 6,000-acre park has been burnt. The park and surrounding area are the residence of one of the largest populations of the toads, numbering about 2,000, and the fires may have devastated their numbers. Because Bufo houstonensis breeds in February and March when the first spring rains arrive, and is not active for most of the year, the fire's effect will be unknown until the next breeding season. (DC)

    • September 5, 2011: A reptile on AmphibiaWeb?! A little over 3 months old, the Global Amphibian Bioblitz has been steadily growing with now 11% of the world’s amphibian species observed by naturalists worldwide. With increasing coverage, it has inspired the Global Reptile Bioblitz, which aims to do the same for the world’s 9,413 species of reptiles. Help spread the word, increase awareness of our fascinating herpetofauna, and make your mark on the Global Amphibian and Reptile Bioblitzes! (MK)

    • August 28, 2011: Think this is a snake? Look again--it's a fanged frog (Limnonectes macrocephalus). Setiadi et al. (2011) report in the journal American Naturalist that a surprisingly diverse adaptive radiation of fanged frogs has taken place on the island of Sulawesi, Indonesia, over the relatively rapid time span of just 15 million years. Fanged frogs (genus Limnonectes) are the only frog group on Sulawesi that have successfully diversified, and body size corresponds strikingly with ecological niche. For instance, small-bodied fanged frogs are found in leaf litter near rivers and have evolved derived modes of reproduction (including viviparity) allowing them to invade terrestrial niches. A comparison with the anuran fauna of the Philippines reveals that the absence of competition (e.g., from the frog genus Platymantis) may have enabled the expansion of Limnonectes into many new niches on Sulawesi. (KW)

    • August 22, 2011: Chytridiomycosis has devastated many species of amphibians in Australia, Central America, Europe, and North America. However, few studies so far have examined the impact this fungal disease is having on Asian amphibians. Now Swei et al. (2011) report in a new PLoS One paper that chytridiomycosis infection prevalence patterns are strikingly different in Asia. The fungal pathogen Bd appears to be widely distributed in Asia (as previously predicted by niche modeling) but at very low prevalence. Also, in contrast to Central America and California, no evidence of a moving epidemic wave has been found, and mass amphibian die-offs do not appear to have occurred in Asia. The implications are that Bd may be either endemic at low prevalence, newly emerging (possibly in the Philippines), or unable to fully invade Asian amphibians. (KW)

    • August 15, 2011: Natural hybridization between species is an important evolutionary mechanism for creation as well as extinction or local extirpation of lineages. The formation, maintenance, and consequence of hybrid zones between species is both an evolutionary and ecological study. Such a study (Hauswaldt et al 2011) on the natural hybridization between the ancient sister lineages of Salamandrina perspicillata and Salamandrina terdigitata, endemic species of the Italian Appennine peninsula, show extensive, ongoing hybridization (up to 80% of the contact population). These two species were only recently distinguished from each other (2005) and little is known of their natural history, which confounds how these species are able to maintain their observed molecular distinctions as species and leads to questions of whether ecological mechanisms may also be in play. (MK)

    • August 8, 2011: Many species of Poison Frogs (Dendrobatidae) are brightly colored and distasteful to predators. A predator, such as a snake or bird, that grabs a poison frog such as Ameerega bilinguis (above) will spit it out and eventually learns to avoid frogs that resemble it. However, the "poison" frog Allobates zaparo (above), in the same family, is not distasteful. Instead, it is a mimic of the distasteful species Ameerega bilinguis. In this phenomenon, Batesian mimicry, the mimic is protected from predators who leave it alone because it resembles the foul-tasting species, called the model. Both model and mimic live in the same region of lowland rainforest in Ecuador. Although some other species of frogs are believed to be Batesian mimics, Allobates zaparo is the only species for which experiments have shown conclusively that predators cannot distinguish it from the distasteful species. Can you tell which species is harmful and which is harmless? (DC)

    • August 1, 2011: Unlike most papers on the deadly amphibian fungal disease caused by Batrachochytrium dendrobatidis, or Bd for short, a recent paper in Frontiers in Zoology evaluate epidemiological solutions to this global crisis, and thus shed hope on the conservation of amphibians. It is clear from their review of Bd pathogenesis that much has been rapidly learned of this organism, and therein lies many of the strategies. From in situ solutions of habitat alterations (e.g. ecosystem engineering) to bioaugmentation and possible immunization with vaccines, these are sophisticated but still untested solutions that nonetheless point to a brighter future. (MK)

    • July 25, 2011: How might montane amphibians respond to climatic warming? Gifford and Kozak studied two southern Appalachian salamanders, Plethodon teyahalee and P. jordani to determine what sets their elevational range limits. Plethodon jordani is intolerant to warmth and is restricted to uplands. In contrast, P. teyahalee, which replaces P. jordani at lower elevations, would thrive at higher elevations, but its range is limited by apparent competition with P. jordani. Ancestors of eastern Plethodon may have been upland forms and phylogenetic conservatism expressed in physiological traits may explain why so many of them are restricted to upland sites. More generally, range limits, often considered to be determined mainly by competition, may instead be determined more frequently by organismal traits. (DW)

    • July 18, 2011: Good news: One of the Lost Amphibian species on Conservation International's top ten list has been rediscovered: Ansonia latidisca, the Borneo rainbow toad. This spectacular arboreal toad had not been seen since a few specimens were collected in 1924. It was rediscovered in a remote area of Malaysian Borneo, after months of searching by a team led by Dr. Indraneil Das of Universiti Malaysia Sarawak (UNIMAS). (KW)

    • July 11, 2011: The Global Amphibian Bioblitz is a recently launched citizen science project, which aspires to observe every species of amphibian around the world. Such ambition requires the efforts of naturalists everywhere in collaboration with AmphibiaWeb, the Smithsonian Conservation Biology Institute, Center for Biological Diversity, the IUCN/SSC Amphibian Specialist Group, and Amphibian Ark. The project website and database is powered by the iNaturalist site where anyone can sign up and participate. Initiated on May 25th, the GAB has already logged in 589 species out of 6,823 known amphibians, 8 % of all species, representing 84 % of amphibian families. Keep up with the progress of the global effort and log in to participate as an observer or communicate with others at the Global Amphibian Bioblitz. (MK)

    • July 4, 2011: Dorsal crests of male newts (family Salamandridae) are particularly conspicuous during breeding season and their origin may be related to the complex courtship behaviors of these salamanders. In a new analysis that combines information on evolutionary relationships with data on morphology as well as behaviors, Wiens and colleagues reveal a complex relationship among these traits. The various dorsal crest traits that characterize mature male newts have been lost repeatedly. The evolution of the dorsal crest may be related to certain specific behaviors such as fanning and whipping of the tail. Species with higher numbers of crest-related traits also have larger repertoires of courtship behaviors. (DCB)

    • June 27, 2011: Hellbenders (Cryptobranchus alleganiensis), known to be rather sedentary sit-and-wait predators, were found in a recent study in Indiana ( Burgmeier et al. 2011) to move further and have larger home ranges than previously thought. More movement occurred during the summer, which is their breeding season, than in the fall. Home ranges were on average 1545 m2, but during the fall home ranges decreased to 644 m2. Hellbenders preferred gravel substrate in flowing water (runs), and also pools over riffles. They used medium to larger sized boulders more frequently than expected. Larger shelter rocks were used in non-summer months with the average movement between frequently-used rocks about 28 m. (CS)

    • June 20, 2011: Poison frogs (Dendrobatidae) are famous for their bright coloration. It is well known the most brightly colored species are protected by distasteful skin alkaloids. A predator that attacks one of these frogs will be unlikely do so again. This combination of defense and conspicuousness is called aposematism. A second and recently documented function of brightness is that females preferentially choose males based on their brightness and color. Now a third advantage is shown. In the strawberry poison frog, Dendrobates pumilio, the bright coloration functions—in male-male competition. Males of this species set up territories that they defend vigorously against other males. When defending his territory, a bright-colored male preferentially approaches brighter (as opposed to dull) intruders, does so more quickly, and directs more calls to these rivals. For these frogs, there are many advantages to being obvious. (DC)

    • June 13, 2011: The enigmatic Vegas Valley Leopard Frog (Rana fisheri) once thrived in springs and associated creeks and ponds in the Vegas Valley of southern Nevada before urbanization destroyed its habitat. By 1942, the species was thought to be extinct. Using ancient DNA methods with frogs fixed in ethanol in 1915 and preserved at the California Academy of Sciences, Hekkala and colleagues (2011, Biological Conservation) have shown that samples of R. fisheri cluster within the northwestern clade (of two clades currently assigned to Rana chiricahuensis), and they have assigned members of that clade (mainly from the Mogollon Rim region) to R. fisheri. The status of the second clade, currently R. chiricahuensis, is now in question, especially important given recent focus on conservation efforts. (DW)

    • June 6, 2011: Tropical amphibians in pristine forests are more likely to be infected by the fungal chytrid pathogen, Batrachochytium dendrobatidis (Bd), than amphibians in deforested areas of the tropics, according to research by Becker and Zamudio (2011), published in PNAS. (JG)

    • May 30, 2011: Although Sri Lanka and India were connected by land bridges several times, most recently at about 10,000 years ago, their faunas do not entirely overlap and clade-level endemism is present. Reinforcing this observation, Meegaskumbura et al. have distinguished a new genus of foam-nesting rhacophorid treefrogs endemic to Sri Lanka. The new genus Taruga contains three species (Taruga fastigo, T. eques, and T. longinasus), all with restricted distributions mainly in Sri Lanka's forested highlands. All three species were formerly considered to be in Polypedates, but both Taruga adults and tadpoles can be distinguished morphologically and molecularly from the more widely ranging Sri Lankan Polypedates species (P. cruciger, P. maculatus). (KW)

    • May 22, 2011: Good news for frogs: Five endemic African frog species, not seen since their descriptions over half a century ago, have been rediscovered in the mountains of eastern Democratic Republic of Congo. A team led by Eli Greenbaum of the University of Texas El Paso found Arthroleptis pyrrhoscelis, Chrysobatrachus cupreonitens, Hyperolius chrysogaster, Hyperolius leucotaenius, and Phrynobatrachus asper on Itombwe Plateau and in Kahuzi-Biega National Park. The remote Itombwe Plateau is one of the most biologically distinctive regions in Africa, with high levels of amphibian and bird endemism and a unique gorilla subspecies, but eastern Congo forest habitats are increasingly being destroyed for agricultural use. (KW)

    • May 16, 2011: In contrast to the limited range of morphological variation in adult frogs, tadpoles have diversified into an impressive array of ecomorphs. In a new recent paper, Roelants, Haas and Bossuyt (PNAS May 9, 2011) used a molecular phylogeny to show that the greatest expansion in morphological types were coincident with the basal anuran radiation. Subsequently, morphospace evolution slowed; extensive morphological evolution associated with the neobatrachian radiation featured homoplasy rather than innovation. (DW)

    • May 9, 2011: Atelopus are the brightly colored Neotropical Harlequin toads. This clade (Bufonidae) has suffered drastic population declines and extinctions of more than half of the 100 species (including A. ignescens pictured above). A phylogeny of approximately 20 species, reveals two patterns (Lötters et al. 2011 Systematics and Biodiversity 9(1):45-5). First, the variable colors and patterns of the species have confounded species delimitations. Second, the traditional delineation into lowland, gracile species and montane, robust species, does not conform to phylogeny. Rather, the group matches biogeography, with a northern Andean-Chocoan-Central American clade, and a southern Andean-Amazonian-Guianan clade. (DC)

    • May 2, 2011: Natural hybridization among recent species has been viewed traditionally as a homogenizing force, but new research has revealed a possible role for interspecific gene flow in facilitating species radiations. Natural hybridization can contribute to radiations by introducing novel genes or reshuffling existing genetic variation among diverging species. Fontenot et al. (2011) examined nuclear and mitochondrial variation in the Bufo (Anaxyrus) americanus group. Their phylogenies from nuclear and mitochondrial data were discordant, due to recent and/or ongoing natural hybridization events and high levels of gene flow between sympatric populations. This group may have benefited from genetic admixtures that have occurred since recent glaciations. (KW)

    • April 25, 2011: In a forthcoming study, Vieites et al. analyze relationships among the major lineages of the most diverse family of salamanders, the Plethodontidae, using DNA sequence data from nuclear genes and complete mitochondrial genomes. They find that the European and Asian plethodontids, Hydromantes and Karsenia, are sister taxa and part of a large clade of North American salamanders. The four-toed salamander, Hemidactylium scutatum, is found to be part of a lineage containing the slender salamanders (Batrachoseps) from western North America and the diverse tropical plethodontid salamanders of Central and South America. Based on these analyses, the authors proposed a revised subfamily taxonomy for the Plethodontidae. (DB)

    • April 18, 2011: In some caecilian species, larvae tear off and consume their mother's skin for nutrition. Now, for the first time, it has been reported that this may occur in an anuran species (Rabb's treefrog, Ecnomiohyla rabborum, from Panama). In an unusual twist, it may be the male parent providing nutrition; tadpoles develop in water-containing treeholes and field observations indicate that the tadpoles appear to rasp the epidermis of the father frog when he immerses his body among them. However, this hypothesis is unlikely ever to be formally tested. Chytridiomycosis has swept through and devastated the amphibian community at the type locality for this species, and only one lone male is known to survive in captivity. Read Mendelson's (2011) essay in Herpetological Review for more. (KW)

    • April 11, 2011: It's not easy being green...unless you're a spotted salamander (Ambystoma maculatum) embryo. Kerney et al. (2011) have documented the first known case of endosymbiosis between a vertebrate and an alga. The green algae are found not only in the jelly coat of the egg but also incorporated into the salamander's embryonic and larval tissues. Although the symbiotic relationship is relatively short-lived, with embedded algal cells diminishing in number as the salamander larva develops, this finding opens new avenues of inquiry into intracellular symbiosis in vertebrates. (MK)

    • April 4, 2011: The Neotropics (tropical areas in Central and South America) contain half of the Earth's remaining rain forests and the largest diversity of amphibian species of any region. A recent study reconstructed the biogeography of a highly diverse group of Neotropical frogs, the poison frog clade (Dendrobatidae). The study rejected an Amazonian center-of-origin for this group of frogs, and instead, concluded that a significant percentage of dendrobatid diversity in Amazonia resulted from repeated immigrations (mostly from the Andes Mountains), with radiations at <10.0 million years ago (MYA), rather than in situ diversification. The study also concluded that dendrobatid frog species in the Andes, Venezuelan Highlands, and Guiana Shield have undergone extended in situ diversification at near a constant rate since the Oligocene. (VV)

    • March 28, 2011: Developmental biologists seeking to understand the genetic and embryological underpinnings for the evolution of the basic shapes and forms used to recognize major groups have long been interested in the Hox genes that control the head-tail axis and major body segments in vertebrates and invertebrates alike. Recently, Mannaert and colleagues (2010) compared Hox gene clusters across amphibians and other vertebrates, and discovered that caecilians had an enlarged section of Hox genes, three times larger than in mammals, which more closely resembled those sections of the gene clusters in coelacanths and snakes, although unique in configuration. Whether the specific gene loss and gain is responsible for limblessness in caecilians remains unclear, but it certainly shows there is more vertebrate variation in Hox genes than previously thought. (MK)

    • March 21, 2011: A special double issue of the journal Diseases of Aquatic Organisms is solely devoted to "Chytridiomycosis: an emerging disease". The double issue (Vol. 92, numbers 2-3: 89 - 260) contains a foreword (by AD Hyatt, R Speare, AA Cunningham, and C Carey) and twenty articles on diverse topics by many authors. Excerpt from the Foreword: Chytridiomycosis "is arguably the most significant recorded infectious disease of any vertebrate class. The disease is reducing amphibian biodiversity across most continents and regions of the world, affecting the resilience of surviving populations and driving multiple species to extinction". The articles range from general overviews (e.g. JP Collins on “Amphibian declines and extinction: what we know and what we need to learn”) to technical studies of the chytrid organism itself or its effects on particular species (such as Leiopelma archeyi) and are global in scope. (DW)

    • March 14, 2011: Manu National Park in southern Peru is a hotspot for amphibian biodiversity, encompassing habitat from lowland tropical rainforest to high-elevation Andean cloudforest. While lowland amphibian species such as this tiger-striped leaf frog Phyllomedusa tomopterna are doing well, chytridiomycosis is wreaking havoc at higher elevations in Manu. Work by Catenazzi and colleagues has documented a dramatic decrease in species richness and abundance for Manu high-elevation anuran species over a 10-year period, particularly in stream-breeding amphibians. Their data support the hypothesis that the pathogenic chytrid fungus Bd is moving southward in a wave along the Andean cordilleras. (KW)

    • March 6, 2011: The giant toads of the forests of West and Central Africa are often feared by local people but also play a role in traditional medicine and lore, including that these toads give birth to the rainbow. Now Barej and colleagues have revised this large, charismatic species by recognizing three distinct lineages. Distinct subspecies of Bufo (Amietophrynus) superciliaris are restricted, respectively, to the Lower Guinean forests and the Upper Guinean forests centered around Ivory Coast and Liberia. In addition, a new species, A. channingi, is described that is so far known only from the war-torn eastern Democratic Republic of Congo, including the Itombwe Plateau, already known for its endemic amphibian species. (DB)

    • February 27, 2011: Kaiser et al. (2011) found that anthropogenic noise decreases both the long- and short-term duration in which male frogs are at the breeding chorus. This is likely to decrease reproductive success because females join the choruses later at night. So, males and females overlap less at the breeding pond. This phenomenon potentially influences population dynamics and may contribute to anuran declines. (DC)

    • February 20, 2011: A five-month long Search for Lost Frogs organized by Conservation International (CI) and the IUCN Amphibian Specialist Group (ASG), with support from Global Wildlife Conservation (GWC), has resulted in the re-discovery of only four species from a "Top 100" list. An additional eleven species that have not been seen for many years were also found. The search involved 126 researchers in 21 countries on 5 continents. (JG)

    • February 13, 2011: Mexican Spadefoot toads (Spea multiplicata) have evolved interesting adaptations for living in North American deserts. Some tadpoles of this species become carnivores, or even cannibalistic, preying on anostracan fairy shrimp and other tadpoles that share their ever diminishing ponds. Whether S. multiplicata tadpoles become carnivorous depends on their mother’s size (Martin and Pfennig 2010). Larger females invest in larger eggs, which become larger tadpoles, and these tadpoles are faster at catching shrimp and more likely to become carnivores. Smaller mothers produce smaller offspring, which become omnivorous tadpoles. Therefore, maternal effects may reinforce character displacement and population divergence in Spadefoot toads and promote the evolution of novel phenotypes. (CS)

    • February 6, 2011: The fungal chytrid pathogen, Batrachochytium dendrobatidis (Bd), is reaping havoc on the world's amphibians causing hundreds of species to go extinct. Most of the attention has been focused on highly susceptible amphibians, yet hundreds of other species appear to become infected with little apparent effect. Whether there are substantial sublethal effects of Bd infection remains unknown. The authors of a currently published story (Han et al. 2011) examined the effects of Bd-sublethal effects on antipredator behavior of tadpoles from four species of western North American amphibians. They found that sub-lethal exposure to Bd can alter fundamental anti-predator behavior in Bufo boreas and suggest that it could increase predation risk in Bd-infected tadpoles. (VV)

    • January 31, 2011: Introduced species are a well-known phenomena in Florida. A recent phylogenetic analysis of two presumably recent introductions, the Greenhouse frog (Eleutherodactylus planirostris) and the Cuban treefrog (Osteopilus septentrionalis), show different patterns of nucleotide sequences compared to populations from their native range (Heinicke et al 2011). The study pinpoints E. planirostris emerging from a single colonization event from western Cuba to the Florida Keys, while O. septentrionalis is from two or more Cuban sites. Divergence times between Cuban and Floridian populations appear to be early enough for E. planirostris to be coincident with the formation of the Florida Keys, while the Cuban treefrog introduction likely was human mediated. The analysis contrasts a longterm resident from a more recent introduction, clarifying their dispersal patterns. (MK)

    • January 22, 2011: In 1985, slightly more than 4,000 species of amphibians were recognized. Today AmphibiaWeb recognizes 6,785 species. The vast majority of those named since 1985 are new discoveries. In 2010, 206 species were added to the AmphibiaWeb database, the largest number added since 2005. Although most of these were tropical frogs, the total also includes 25 salamanders (mostly in the tropics) and 5 caecilians. The rate of increase in numbers of new species continues to be high (3.13% in 2010, a surprising 59% since 1985), with no indication that the rate of discovery and description is slowing. (DW)

    • January 17, 2011: Although the amphibian chytrid fungal pathogen Batrachochytrium dendrobatidis (Bd) has devastated amphibian populations in many parts of the world, and initially it was thought that the pathogen might have spread through global trade of infected African pipid frogs, the prevalence and distribution of this pathogen in Africa is still not well known. Gabon has now been added to the list of countries in which Bd is widely prevalent. See Bell et al. (2011) in the journal EcoHealth for more details. (KW)

    • January 10, 2011: Vampire tadpole? A new species of rhacophorid treefrog from Vietnam, just described in Zootaxa by Rowley et al. (2010), has an unusual tadpole. Larval Rhacophorus vampyrus have a pair of black "fangs" (keratinized hooks) on the lower labium that curve away from the reduced mouthparts. To view a photo of the tadpole, go here. This species deposits its eggs in foam nests within small treeholes. (KW)


    back to News by Year

    • December 26, 2010: Climate change may affect many aspects of an animal's life, including breeding biology. In a recent paper, Brian Todd and colleagues found that four of ten amphibian species studied over a 30-year period have shifted the date when they arrive at their breeding site. Two autumn-breeding species and two winter-breeding species using the same wetland were found to have shifted breeding migration dates. Significantly, the onset of breeding in these species now coincides, whereas it had previously been separated by several months, and suggests that climate change can affect interactions among species. This change in reproductive timing is one of the largest reported to date and coincides with an increase in overnight air temperatures over the past 30 years. (DW)

    • December 16, 2010: Do you use AmphibiaWeb for mapping amphibians, checking out new species, getting titles of new amphibian decline papers (see Latest Papers button), scoping out Species of the Week, reading about the factors contributing to amphibian declines, finding out more about the natural history of a particular species, searching for all the caeciliids in India, or showing your herpetology class that you can see photos of every frog family simultaneously with our taxonomic photo browser? Please consider including AmphibiaWeb in your holiday gift-giving plans!

    • December 9, 2010: IUCN has created a wiki page for the Amphibian Red List Authority, which has now been made available for viewing by the broader herpetological community. If you are interested in finding out more about how IUCN conducts its amphibian conservation assessments, this wiki is a very useful collection of resources. (KW)

    • December 2, 2010: Although the frog's jump is among the most familiar of all modes of locomotion in vertebrates, much remains unknown about the diversity and evolution of locomotion in frogs. Reilly and Jorgensen (2010), in a new Journal of Morphology paper, have used detailed anatomical studies (including x-rays and micro-CT imaging) to more thoroughly document the diversity of frog pelvic anatomy. They find that anatomy associated with walking and hopping is common among the earliest diverging lineages of living frogs. In contrast, specialized anatomy associated with long-distance jumping evolved multiple times and is found only within neobatrachian frogs. To see one of Reilly and Jorgensen's CT images (the pelvis of Ptychadena anchietae, an African ranid that is a long-jumping frog), view the AmphibiaWeb Facebook page. (DCB)

    • November 29, 2010: Alkaloid skin toxins have now been reported from two species of Cuban frogs in the family Eleutherodactylidae. This is the first eleutherodactylid lineage known to be toxic. Rodríguez et al. (2010) show that Eleutherodactylus iberia (and to a lesser degree, E. orientalis) have lipid-soluble alkaloid skin toxins (pumiliotoxins and indolizidines). As is the case for other toxic lineages such as dendrobatid and mantelline frogs, the skin alkaloids are thought to be sequestered from dietary sources (mites). Both Cuban species are miniaturized; in particular, Eleutherodactylus iberia is the smallest known frog in the Northern Hemisphere and one of the smallest in the world. Miniaturization, along with dietary specialization in tiny prey (mites and ants), is thought to have preceded the evolution of alkaloid sequestration, aposematic coloration and diurnality in anuran taxa.(KW)

    • November 22, 2010: Find your amphibian species of interest! AmphibiaWeb is now generating maps for newly described species, as well as for previously known species. For new species, we map the type locality. Maps can be accessed via the link at the top of all species account pages: "View distribution map using BerkeleyMapper." See the account for the new Nicaraguan salamander species Oedipina nica, for an example. Type localities have been mapped for all new species added to AmphibiaWeb through September 28, 2010, and will be updated on a regular basis; these maps will also be shared with IUCN/GAA. (KW)

    • November 18, 2010: Not only Haiti's people but Haiti's wildlife face great challenges. Haiti has the highest percentage of threatened amphibians, of any country: 92% of the amphibian species that have been assessed are in danger. Half of Haitian amphibians are endemics (28 of 57 species). Habitat loss presents the gravest threat. Only about 1% of the original forest now remaining in Haiti; what remains is rapidly being cut down for charcoal to be used in cooking fires. A new species-rescue initiative to save Haiti's frogs is now underway. Dr. Blair Hedges of Penn State has started a captive-breeding program for ten critically endangered species of Haitian frogs, in collaboration with the Philadelphia Zoo. Hedges' lab has also established a cryobanking program. (KW)

    • November 17, 2010: Conservation International's search for "Lost Frogs" has led to the discovery of three new frog species in Colombia (not yet formally described). Although the team did not find the Mesopotamia beaked toad (Rhamphophryne [Rhinella] rostrata, probably extinct), they did come across a tiny new species of beaked toad (genus Bufo [Rhinella]), a new rocket frog (genus Silverstoneia, family Dendrobatidae), and a new montane toad with vivid ruby eyes (genus unknown). See the BBC story and the CI press release for photographs. (KW)

    • November 11, 2010: AmphibiaWeb has reached a milestone! We now have 20,000 amphibian photos, representing over half of all extant amphibian species. Many thanks to all of our talented photographers, and thanks also to CalPhotos for hosting the images. Congratulations to Dave Blackburn of KU for submitting the 20,000th photo, especially since it is of a species just described (Arthroleptis palava). In celebration, we would also like to announce a new feature: AmphibiaWeb now has a taxonomically organized photo browser. You can access this using the "Search the Database" button on the home page or on the left of any other page, and then choose the blue tab "Browse Photos". Check it out! (KW)

    • November 8, 2010: Through recent efforts such as the Global Amphibian Assessment, we have a nearly comprehensive view of amphibian diversity, distributions, and threats. But what about the people studying and describing amphibian species? In a new BioScience paper, Rodrigues et al. (2010) document the distributions, regional expertise, and ages of active amphibian taxonomists. Europe and North and Central America are net exporters of taxonomic knowledge to many other regions. South America has a relatively young population of amphibian taxonomists, compared to Asia. Africa is most in need of local amphibian taxonomic expertise. This work highlights the need for taxonomic training and particularly increased local expertise throughout many regions of high amphibian diversity. (MK)

    • November 4, 2010: A new initiative to find missing amphibian species in India has been announced: Lost! Amphibians of India. Scientists from the University of New Delhi, Conservation International, the IUCN/SSC Amphibian Specialist Group, the Natural History Museum (London), the Wildlife Conservation Society, and Global Wildlife Conservation are on the hunt for 47 amphibian species not seen in India for many years. In tandem, a new partnership (the Western Ghats Network of Protected Areas for Threatened Amphibians, or WNPATA) has been created to protect amphibian habitat in the Western Ghats, one of the ten richest hotspots for biodiversity in the world. (KW)

    • November 1, 2010: In comparison to other families of frogs found in Africa, the family Brevicipitidae remains poorly known. In a new study, Loader et al. (2010) describe three new species of Callulina, a genus restricted to montane forests of East Africa. Unlike most brevicipitids which are burrowers, species of this enigmatic genus are often found climbing on vegetation. For nearly a century, there was only one recognized species of Callulina, but since 2004 five more have been described. Each species appears to have a very localized distribution. In combination with ongoing loss of forests in the region, their restricted ranges suggest that conservation measures may be needed to protect these unusual frogs. This study also further highlights the northernmost Eastern Arc Mountains as a place of high species-level endemism. (DCB)

    • October 25, 2010: Frogs have teeth, but did you know that tadpoles do too? Tadpole teeth are not true teeth but are instead independently evolved and developed structures made up of keratin (called labial teeth, keratodonts, or denticles). Vera Candioti and Altig (2010) investigate whether shape diversity among tadpole keratodonts might be explained by shared evolutionary histories and/or by being members of similar ecological guilds. The authors find that 35% of shape variation can be explained by common ancestry and that suctorial tadpoles have much broader keratodonts than other ecological guilds, possibly for better grasping the substrates in habitats such as fast-moving streams. The authors do not find clear relationships between keratodont shape and diet. This study will serve as a baseline for future work on understanding the relationship between the form and function of these uniquely tadpole structures. (DCB)

    • October 14, 2010: During metamorphosis, the skeletons of amphibians change dramatically. In a recent study published in the Journal of Zoological Systematics and Evolutionary Research, Weisbecker and Mitgutsch (2010) investigate the degree to which these patterns of skeletal change are conserved across the evolutionary history of frogs. After analyzing a compilation of data on ossification sequences from past literature, the authors find relatively little conservation of developmental patterns. The authors include data for both miniature species and those with derived life histories (such as direct development), but, importantly, do not find a clear relationship between patterns of ossification sequence and these important organismal traits. (DCB)

    • October 11, 2010: What factors influence whether frogs can recolonize a site after a local extinction? Landscape genetics focuses mainly on how habitat features (topographic complexity) between sites can influence gene flow. However, other factors influence frog populations such as distance between suitable breeding sites and local factors such as whether predatory fish are present. In a new Molecular Ecology paper, Murphy et al. (2010) use the novel approach of gravity modelling (previously used only in economic geography and transportation) to capture the complexity of factors affecting Rana luteiventris (Columbia spotted frog) gene flow. (KW)

    • October 5, 2010: Chytridiomycosis is in the NY Times today, with an article on Vance Vredenburg's work. He is trying to save the last of the Sierra Nevada yellow-legged frogs (Rana sierrae) left in the wild from chytridiomycosis, by using the novel method of bacterial bioaugmentation. Check out both the print article and the audio slideshow. (KW)

    • September 27, 2010: Good news: A rare cave-dwelling salamander species has been rediscovered in Mexico after 73 years. Despite extensive searches Chiropterotriton mosaueri, the cave splayfoot salamander, had not been sighted since it was discovered in 1937 (it was formally described in 1941) and was feared to be extinct. AmphibiaWeb congratulates Dr. Sean Rovito (a postdoctoral fellow at UNAM) on finding this species, and Conservation International for its support of this expedition as part of its campaign to "Search for the Lost Frogs." Even better news: Last week three different CI expeditions reported success in finding their amphibian targets. Congratulations to all! (KW)

    • September 20, 2010: Ontogenetic color change, where the juvenile has a very different coloration from the adult, is unusual in frogs. In Stumpffia be, a new microhylid species from Madagascar, the juvenile has bright blue spots on a dark background, in contrast to the relatively plain light brown adult. This species is part of a newly described radiation of cophyline microhylids that apparently live mainly in karstic limestone caves (a new habitat for cophylines) and have re-evolved larger body size from miniaturized ancestors. See Köhler et al. (2010) in the latest issue of the Journal of Zoology. (KW)

    • September 13, 2010: Are Neotropical direct-developing frog populations that have survived Bd epidemics still at risk, and what factors influence survival? Direct-developing species are the most likely to survive in Neotropical highland forests, since they do not breed in water and thus have less exposure to the aquatic infectious zoospore stage of Bd. In Puerto Rico, Bd arrived in the mid-1970s and has decimated many amphibian species. Longo and Burrowes (2010), in a new Ecohealth paper, show that populations which have somewhat recovered from Bd-influenced declines (Eleutherodactylus coqui and E. portoricensis) are still at risk. Infection persists in these populations and continues to hinder survivorship. Juveniles are more susceptible to infection than adults and carry higher infection loads, particularly at mid-elevations. (KW)

    • September 6, 2010: Bolitoglossa jacksoni is one of the ten "most wanted" amphibians in Conservation International's 2010 campaign to search for lost amphibian species. This spectacular salamander is endemic to western Guatemala and has not been seen for 35 years. Only two individuals have ever been found (both in 1975). Although there is no habitat left at the type locality for B. jacksoni, a second potential locality will be explored. A team will go out for a short search in mid-October, and a second team will conduct a more extensive search in mid-November, led by Carlos Vasquez of the Museo de Historia Natural, Universidad de San Carlos de Guatemala. (KW)

    • August 30, 2010: A tiny new frog (the Old World's smallest) has been discovered living and breeding inside pitcher plants on Borneo. Adult males of Microhyla nepenthicola measure between 10.6 and 12.8 mm; new metamorphs measure just 3.5 mm on average (one-third the diameter of a pea). Although pitcher plants are carnivorous and consume insects that fall in, the tadpoles suffer no ill effects from developing inside the pitcher's digestive liquid. Das and Haas (2010) describe the new frog species in the journal Zootaxa. In September, Das will be leading one of a number of Conservation International teams searching for "lost" amphibian species that have not been seen in the wild for many years. (KW)

    • August 23, 2010: The lethal amphibian disease chytridiomycosis has been detected in numerous regions worldwide, but sampling in Asia has been very patchy. The first report of chytridiomycosis in China has been published in the August issue of the journal EcoHealth, by Bai et al. (2010). Both native amphibian species and introduced bullfrogs (wild, farmed, and market-sold Rana catesbeiana) were found infected in Yunnan province. Bullfrogs are known carriers of the chytrid fungal pathogen Batrachochytrium dendrobatidis and are widely bred for both domestic and international consumption on frog farms in China. The authors call for strict regulations on bullfrog breeding and transport in China, and point out the urgent need for monitoring of native Chinese amphibians for chytridiomycosis. (KW)

    • August 16, 2010: What is the longest-lived amphibian and what traits predict longevity? Generally body size is tied to longevity, as larger animals such as elephants tend to have longer lifespans. Now the neotenic cave-dwelling salamander Proteus anguinus (known as the olm) has proven the exception, with a body mass of just 15-20 g (less than 3/4 ounce) but a predicted maximum lifespan of over a century. A new paper by Voituron et al. (2010) has analyzed over 50 years' worth of weekly records from a 400-animal captive breeding colony in the French Pyrenees. The average adult olm lifespan was 68.5 years; sexual maturity was attained at 15.6 years, on average. In contrast, the next longest-lived amphibian is the Japanese giant salamander (Andrias japonicus), weighing over 30 kg but with a maximum lifespan of only 52 years in captivity. (KW)

    • August 13, 2010: Why did a rare, critically endangered African frog species suddenly die in high numbers on Mount Oku, Cameroon? Is a new, unknown pathogen responsible, or could it be due to lake acidification? In analyzing specimens of dead Xenopus longipes from a 2006 mass mortality event, Blackburn et al. (2010) found no evidence of chytrid infection or ranaviruses. No other amphibian species in Lake Oku, or in nearby watersheds, were observed to suffer mass mortality in the same time period. This paper serves as a reminder that amphibians face many threats and that chytridiomycosis is not the only suspect in enigmatic amphibian declines. Xenopus longipes is found solely in a single high-altitude crater lake on Mount Oku in Cameroon. This species is one of only two vertebrate species known to be dodecaploid (12n). (KW)

    • August 11, 2010: Intracellular symbiosis with photosynthetic organisms has long been documented for invertebrates, such as corals, but was thought impossible for vertebrates. Now a "solar-powered salamander," the first vertebrate to harbor a photosynthetic symbiont inside its cells, has been reported at the recent Ninth International Congress of Vertebrate Morphology in Uruguay.

      Embryos of spotted salamanders (Ambystoma maculatum) have been found to contain many single-celled algae, of the species Oophila amblystomatis. Previously it had been thought that vertebrates were not capable of harboring intracellular symbionts due to the vertebrate adaptive immune system, which is responsible for recognizing and destroying "non-self" biological material. For a commentary , see Petherick (2010) in Nature. (KW)

    • August 7, 2010: Can tectonic activity be traced with frogs? What can spiny frogs with Popeye-like forearms and sandpaper-like chests, living in cascading Asian mountain streams, tell us about the formation of the Himalayas? Geologists have long debated how the India-Asia collision led to the rise of the Himalayas and the Tibetan Plateau. Now biologists have used frog evolution within the tribe Paini (family Ranidae) to support a lesser-known model of the geological processes forming this area: the ramming of the Indian plate against Asia did not simply push up the Himalayas, but rather took place in a discontinuous series of northward jumps, first forming Southeast Asia, then pushing South China to the east, and then Central China to the northeast.

      For author commentary see the U.C. Berkeley press release; for the open-access paper, see Che et al. (2010) in the August 3 issue of PNAS. (KW)

    • August 2, 2010: A significant new collection of photos has been added to AmphibiaWeb by the University of Kansas Biodiversity Institute's Division of Herpetology. Of the 559 photos contributed, 328 species were not previously represented by photos in AmphibiaWeb, and 108 are holotypes. Thanks go especially to Dave Blackburn of KU for organizing the photo additions, to Bill Duellman for contributing so many of his own photos, and to Rafe Brown and Linda Trueb, as well as to the many KU photographers who have permitted their images to be publicly displayed on AmphibiaWeb. All copyrights are held by KU's Division of Herpetology. (KW)

    • July 26, 2010: How deeply are amphibian communities affected by disease-driven declines and extinctions? How can species loss be quantified, particularly in tropical assemblages where many cryptic species are present? A new paper by Crawford et al. (2010) shows that the extensively studied amphibian community at El Copé, Panama, lost 41% of its phylogenetic diversity (30 of 74 species, in a 4 km2 area) after being devastated by a chytridiomycosis epidemic. Only 63 species had been described; DNA barcoding analysis of specimens revealed an additional 11 species, of which 5 had already been extirpated from the site. The loss of undescribed species is thought likely to be even higher in chytridiomycosis-affected areas not as well studied as El Copé. (KW)

    • July 17, 2010: A new gliding frog has been described, Norhayati's Gliding Frog (Rhacophorus norhayatii) by Chan and Grismer (2010), from northwest and extreme southern Thailand and Peninsular Malaysia, and possibly Sumatra. AmphibiaWeb thanks Peter Janzen (who has contributed 687 photos in total) for the photo of this new species. To see a gliding frog in full glide, check out John Clare and Kurt Kunze's great photo in the R. reinwardtii species account. (KW)

    • July 14, 2010: Can amphibians in the wild be saved from the deadly fungal disease chytridiomycosis, using bioaugmentation of naturally occurring amphibian anti-fungal skin bacteria? This summer will be the first test, in California.

      Mountain yellow-legged frogs (Rana muscosa and Rana sierrae) were once the most common vertebrates in the Sierra Nevada mountains but now are critically endangered, with many populations decimated by chytrid fungal infection. Wild frogs carry many different kinds of beneficial skin bacteria; at least one secretes a peptide called violacein that protects wild frogs against infection by the fungal pathogen Batrachochytrium dendrobatidis (Bd). Mountain yellow-legged frog populations that have little to no violacein-secreting bacteria succumb to Bd fungal infection and suffer mass mortality.

      In the lab, inoculation with these naturally occurring beneficial bacteria (bioaugmentation) works to protect frogs (and salamanders) against fungal infection and death from chytridiomycosis. Vance Vredenburg of SFSU will lead a project in August 2010 to see whether bioaugmentation can help save some of the few remaining wild mountain yellow-legged frogs in Sequoia and King's Canyon National Park. See the July 2010 Scientific American article for more details. (KW)

    • June 21, 2010: What distinguishes invasive amphibian species at the earliest stage of becoming invasive? Tingley et al. (2010) found that introduced amphibian species were biased taxonomically, with about 50% of introduced species coming from only 3 families: Hylidae, Ranidae, and Salamandridae. Introduced amphibian species were primarily from the Northern Hemisphere. As has been found for introduced mammals, birds, and fish, introduced amphibians had a broad geographic range and were associated with locations having high human density. Large species were more likely to have been transported intentionally, while smaller species were more likely to have been stowaways. Large species also tend to have life history traits associated with successful invasion (high fecundity, mobility, etc.). Ninety percent of caudate introductions were found to be intentional. (KW)

    • June 19, 2010: Frogs get a leg up, as California's Fish & Game Commission voted 3-2 last month to uphold their recent decision to ban importation of non-native frogs (mainly bullfrogs, Rana catesbeiana) and turtles for use as food. Bullfrogs are voracious predators of native amphibian species (such as Bufo californicus) and are asymptomatic carriers of amphibian chytrid fungus (Bd), which has decimated native Californian species such as Rana sierrae. Nearly 1.6 million live ranid frogs are imported per year into the port of San Francisco alone; testing of marketplace-sold bullfrogs in SF, NY, and LA showed that 62% were infected with Bd (Schloegel et al. 2009). (KW)

    • June 10, 2010: Can chytridiomycosis be treated in the wild? Researchers are trying different strategies to help frog populations most threatened by this fungal disease. In Mallorca, Spain, Jaime Bosch's group has been evacuating midwife toad tadpoles (Alytes obstetricans) and treating the tadpoles with antifungal baths in captivity. Bosch's group also attempted to eradicate the fungus in the tadpoles' home pond before releasing treated tadpoles back to the wild. In the Sierra Nevada mountains in California, Vance Vredenburg's group has been treating adult mountain yellow-legged frogs (Rana sierrae) in the wild, with short fungal baths once daily for a week. Initial results are mixed but promising. Read the news feature in the June 10th issue of Nature for more. (KW)

    • May 31, 2010: Will frogs be able to successfully adapt to increasing global temperatures? A new study by Phillimore et al. (2010) suggests that projected increases in temperature may be more than the common frog Rana temporaria can handle, due to local adaptation. First spawning date for populations in southeast Britain will need to advance by about 21-39 days, but genetically influenced plasticity in spawning date may only allow an advance of 5-9 days. Gene flow northward from more southern populations already adapted to higher temperatures could help, but is unlikely due to the barriers of the English Channel and high urbanization. (DW)

    • May 26, 2010: Red-eyed treefrog tadpoles (Agalychnis callidryas) can sense vibrations while the tadpoles are still in the eggs, and decide whether those vibrations are from predators or rainstorms. If the predator is a snake, the entire clutch will hatch synchronously to avoid being eaten. Now Caldwell et al. (2010) have shown that adult male red-eyed treefrogs also use vibrational signaling in male-male aggressive interactions, by shaking a branch rapidly with their hind legs. Substrate vibrations may be far more important in communication by arboreal vertebrates than previously realized. Check out the video in the original paper, and see also the commentary in ScienceNow. (KW)

    • May 19, 2010: If you missed hearing Dr. Vance Vredenburg discuss the amphibian decline crisis on this past week's NPR: Science Friday radio show, you can download the podcast here. Look for the May 14th segment titled "Is The Planet Facing A Mass Extinction?"

      You'll also hear Dr. Barry Sinervo (UCSC) discuss his new research on lizard extinctions and climate change (just published in Science). Other participants are Dr. Tony Barnosky (UCB) and Dr. George Amato (AMNH). (KW)

    • May 17, 2010: Does body shape affect locomotion or burrowing ability in caecilians? (in particular, are caecilians with more elongated bodies less efficient burrowers?) Apparently not as much as had previously been thought. Usually caecilians are active burrowers, but some prefer not to dig their own burrows; also, some species spend less time burrowing and more time foraging above ground, and a few are aquatic. Previous work showed that burrowing ability depended on using skin-vertebral attachment to generate force. In support, aquatic caecilians have lost skin-vertebral attachment, and it had been previously hypothesized that highly elongated species might also have lost that attachment. Herrel and Measey (2010) used X-ray video to examine caecilian locomotor mode on different substrates. The authors showed that both elongated and robust terrestrial caecilians were able to use internal concertina locomotion in soils, and that one robust species had higher skin-vertebral attachment but still preferred not to dig its own burrows. (KW)

    • May 10, 2010: Why do some frogs (and populations) die from chytridiomycosis but not others? A pair of new long-term studies reveals that infection intensity is key; once a critical threshold of Bd fungal infection is reached, death ensues. Population extirpation is the most common outcome, but a few mountain yellow-legged frog (Rana sierrae and Rana muscosa) populations have survived in low numbers. Modeling shows that disease outcome at the population level (extirpation vs. persistence) can result solely from density-dependent host-pathogen dynamics, which may hold for other wildlife diseases as well. See Vredenburg et al. (2010) and Briggs et al. (2010) in PNAS for more. (KW)

    • May 7, 2010: Captive breeding is a last resort to save endangered amphibians, but many species do not breed well under suboptimal captive conditions. A new protocol has been developed for artificially inducing ovulation and fertilization in captive amphibians by Trudeau et al. (2010), published in Reproductive Biology and Endocrinology. Injecting a combination of a gonadotropin-releasing hormone (GnRH) agonist and a dopamine antagonist successfully induced breeding in ranid, ceratophryid, and cycloramphid anurans. (KW)

    • May 1, 2010: The first amphibian genome has been sequenced, for Xenopus tropicalis, enabling new insights into vertebrate evolution and the last common ancestor of tetrapods. Despite amphibians having diverged about 360 mya from mammals, birds, and reptiles, Hellsten et al. (2010) report that there is considerable sequence and gene order conservation. However, mammalian genomes have undergone far more chromosomal rearrangements. Many aspects of the vertebrate immune system are conserved, but unique to the amphibian genome are genes that code for antimicrobial peptides. See the latest issue of Science for more. (KW)

    • April 26, 2010: Although mountain yellow-legged frogs (Rana muscosa) were once numerous in California, today fewer than 200 adults remain in the wild, with small populations in the San Gabriel, San Bernadino, and San Jacinto Mountains of Southern California. The San Diego Zoo Institute for Conservation Research has succeeded in getting a captive breeding program going for this species. Last week the first reintroduction to the wild took place, as biologists reintroduced about 500 eggs into deep permanent pools at the University of California Riverside’s James San Jacinto Mountains Reserve. (KW)

    • April 18, 2010: A new paper from Acta Zoologica (Natale et al. 2010) reports that the tadpole of Ceratophrys ornata makes distress calls underwater. Although the paper claims that it is the first example of any larva communicating by sound underwater, and the first known of any vertebrate larva to make sounds, it is actually the second species known to do this (the first amphibian tadpole reported to make sounds underwater was Gephyromantis corvus, from Madagascar; see Glaw and Vences 1994). Ceratophrys ornata tadpoles are able to make the calls as early as three days after hatching, and can do so both in the water and out of the water. It is not known how other tadpoles perceive the calls, but while C. ornata larvae are carnivorous towards tadpoles of other species, they do not consume conspecific tadpoles. (The tadpole of Gephyromantis corvus is also carnivorous.) To hear the sound made by a Ceratophrys ornata tadpole, check out the two video clips in the associated BBC news story. (KW)

    • April 15, 2010: An amphibian documentary worth viewing: Why Frogs Call and Why We Should Listen (Ravenswood Media, 2009, 32 minutes). David McGowan's excellent footage succeeds in illustrating not only why frogs call and how frogs have evolved but also shows why amphibians are crucial biological indicators and illustrates the importance of wetlands to both frogs and humans. His compelling film serves to draw attention to the need for wetlands conservation as well as the consequences, both to amphibians and to humans, of continuing on our current path. Various clips from the film are available to view freely online, or the complete film can be purchased on DVD at

      This film tells a compelling, tightly edited story, beginning with individual frogs calling in the wild and a discussion by researcher Carl Gerhardt (University of Missouri) of frog reproduction and how frog calls serve both to attract mates and repel competitors, sometimes within the same call. As Anne Maglia (MIssouri University of Science and Technology) then points out, frogs have had the ability to hear (and thus have probably been calling) for at least 190 million years, since the 190-million-year old fossil frog Notobatrachus has clearly visible middle ear bones (stapes). She reviews the fossil evidence of frog evolution and shows how frogs have evolved to become as specialized for jumping as birds are for flying. Amphibians that depend on water for breeding often mate in wetlands, which Robert Brodman (St. Joseph's College) points out are actually the most productive ecosystems on the planet, more so than tropical rainforest or coral reefs. However, wetlands are disappearing rapidly as they are drained and filled in for farmland or urban development.

      Destruction of wetlands is not unique to the United States, as Caroline Aguti (University of Makerere) shows for Uganda; community education as to the value of wetlands can help. Wetlands are also threatened by chemicals; Val Beasley (University of Illinois) discusses the decline of a formerly common wetland-dependent frog species, the cricket frog (Acris crepitans), and the spikes he saw in reproductive abnormalities (intersex frogs, having both a testis and an ovary) coincident with the introduction of polychorinated biphenyls (PCBs) beginning in 1930. From 1946 to the 1960's, the frequency of intersex frogs showed yet another rise, this time coincident with the introduction of the pesticide DDT. Wetlands are under threat not only from pesticides but also from fertilizer runoff; Michael Lannoo (Indiana State University) illustrates how frog deformities are the end result in a chain that begins simply with more nutrients (fertilizer) coming into wetlands. As habitat loss pushes frogs into smaller and more altered habitat such as urban ditches, Karen Glennemeier (Audubon Society) shows how non-scientists can contribute by helping to monitor wetlands, using frog calls as the easiest way to assess biodiversity and thus the health of the wetlands. The film is brought to a close with some lovely images of wetlands and Val Beasley's positive comments on how wetlands have the ability to restore themselves if humans will only allow it to happen.

      No film is perfect. It would have been nice if species were identified when they are seen in the film, but all seventeen individual species are identified in the individual clips, in a separate section of the DVD. The film touches on just a few aspects of the global amphibian decline crisis (though in fairness, it is a short film). It gives the impression that all amphibians depend on wetlands, which is not the case; many species lay terrestrial eggs (and a few give birth) and do not require bodies of water at all for breeding. Finally, although USGS presence/absence maps by counties (or other civil divisions, for certain states) are provided in a separate section of the DVD, there is no map legend for the color coding, and it is not clear how up-to-date or accurate these maps are, looking at the information provided.

      Ravenswood has also made other DVDs and freely available "webumentaries" on topics such as cave biota, fishes in the Great Lakes, wildlife veterinary medicine, white nose syndrome in bats, and making ditches into better habitat. These can also be accessed via (KW)

    • April 12, 2010: The Smithsonian is partnering with George Mason University to offer a course in amphibian monitoring and conservation next month (May 16-28), at the National Zoo's Conservation and Research Center in Virginia. The course will include lectures, lab and field exercises, and case studies. (KW)

    • March 29, 2010: Can frogs with foam nests help make biofuels? The túngara frog (Engystomops pustulosus = Physalaemus pustulosus) creates long-lasting foam nests to help protect its tadpoles. Now a team of researchers has designed a novel artificial photosynthesis system suspended in a foam, using the túngara frog surfactant protein Ranaspumin-2. The system could produce up to 10-fold more biofuel per hectare than plants and could be used on rooftops and nonarable land (Wendell et al. 2010, in the journal Nano Letters). (KW)

    • March 23, 2010: Neurergus kaiseri, the Lorestan newt, has just been granted protection from international trade under CITES Appendix I, as of March 21, 2010. This striking salamander is known from only four streams in the remote Zagros Mountains, Iran. Population levels have declined significantly over the past 10 years, primarily due to overcollection for the pet trade. Fewer than 1,000 individuals are estimated to be left in the wild. Originally the CITES secretariat was planning to deny N. kaiseri protected status, but last-minute intervention by a number of biologists convinced delegates that this species should be included. (KW)

    • March 20, 2010: The California red-legged frog (Rana draytonii), made famous in the Mark Twain story "The Celebrated Jumping Frog of Calaveras County", has been extirpated from 99% of its Sierra Nevada range and is believed to be extinct in the Central Valley. Breeding populations remain along the coast, from San Mateo County to San Luis Obispo County. In 1996, it was declared a threatened species and over 4 million acres of habitat were designated as critical. However, in 2006 developers sued and 90% of that habitat designation was lost. Now that has been partially remedied, thanks to legal action by the Center for Biological Diversity. As of March 16, 2010, the U. S. Fish and Wildlife Service has designated 1.6 million acres of habitat as critical, and the agency has acknowledged that the earlier reduction was flawed because of political interference from the Bush Administration. (KW)

    • March 15, 2010: Did global warming contribute to the extinction of the golden toad (Bufo periglenes) by facilitating chytridiomycosis, as Pounds et al. (2006) suggested? A new PNAS paper by Anchukaitis and Evans (2010) says no. Using oxygen isotope data from old-growth trees, the authors reconstruct a century of climatic data for the Monteverde Cloud Forest Reserve, Costa Rica, and found no long-term warming or drying trend. Instead cloud forest ecology changes appear to have been driven by natural variability in the local climate (in particular, extreme dry periods associated with El Niño weather patterns) rather than by anthropogenic climate forcing. However, Pounds (who lives and works in Monteverde) commented to ScienceDaily that his own data from 40 years of rainfall and mist-cover measurements show that the weather is becoming more variable and more extreme. (KW)

    • March 8, 2010: Atrazine is the most common pesticide contaminant in ground, surface, and drinking water. It also is a potent endocrine disruptor at very low concentrations across vertebrate taxa. In a new PNAS paper, Hayes et al. (2010) showed that atrazine exposure during larval development at levels below the EPA drinking water standard can profoundly affect male Xenopus laevis sexual function and morphology. In the most severe cases, male frogs were completely feminized morphologically and behaviorally, producing eggs and mating with other males.

      Amphibian declines may be due not only to disease and habitat loss, but to failure to reproduce (see the recent review by Hayes et al. 2010 in the Journal of Experimental Biology).

      However, neither Syngenta (the manufacturer of atrazine) nor the EPA have so far accepted previous research, with the EPA saying only that sufficient data exists to form a hypothesis that atrazine can affect amphibian development, but that studies done up to 2007 have neither confirmed nor refuted such a hypothesis. See Renner (2008) for a commentary on reproducibility of atrazine experiments carried out using Xenopus. The EPA does state that it "has begun a reevaluation of atrazine's ecological effects, including potential effects on amphibians, based on data generated since 2007." (KW)

    • March 3, 2010: The California tiger salamander (Ambystoma californiense) has finally been granted protected status under the California Endangered Species Act, by a 3-2 vote of the California Fish and Game Commission on March 3, 2010. This native Californian species depends on ephemeral vernal pools for breeding, 95% of which have been lost in recent decades. (KW)

    • March 1, 2010: The first known monogamous amphibian species (Dendrobates imitator) has been reported (Brown et al. 2010, in a paper to be published in the April issue of American Naturalist). Ecological factors appear to have driven the evolution of monogamy; this species breeds in tiny pools that lack food resources for tadpoles, necessitating parental care. A closely related species (D. variabilis) that breeds in larger pools is not monogamous and mothers of that species do not feed unfertilized eggs to tadpoles. (KW)

    • February 18, 2010: Do you use AmphibiaWeb in teaching your herpetology or undergraduate biology course? Please contact us and let us know the course you are teaching, the college or university, and how you are using AmphibiaWeb. Would you like to make a broader impact and have your students contribute species accounts to AmphibiaWeb, as part of your class? Students get authorship, and all accounts are edited before going public. Classes from U. C. Berkeley, Harvard, Black Hills State, San Francisco State University, and Cal State Stanislaus have written (or are writing) accounts.

    • February 15, 2010: Although chytridiomycosis has devastated many amphibian populations worldwide, it remains unclear whether the fungal pathogen responsible (Batrachochytrium dendrobatidis) is a new emerging pathogen or an endemic pathogen that has been exacerbated by environmental changes. A new paper by Walker et al. (2010) uses Bayesian modeling as well as genotyping to examine Bd occurrence on the Iberian peninsula, the site of the first European outbreak of chytridiomycosis. These authors conclude that Bd is a novel pathogen in Iberia but that heterogeneity in population response is due to both biotic and abiotic variables.

      For a recent review of the ecology and impact of chytridiomycosis see Kilpatrick et al. (2009), in Trends in Ecology and Evolution. See also Fisher et al. (2009), in the Annual Review of Microbiology. (KW)

    • February 8, 2010: A team of American and Ecuadorian scientists working for the nonprofit organization Reptile and Amphibian Ecology International, has discovered an estimated 30 new species of rain frogs (genus Pristimantis) at a site in coastal Ecuador. Nearly half of the new species come from a small cloudforest patch on Cerro Pata de Pájaro. Mountaintop cloudforests and surrounding rainforest usually contain high biodiversity and are under threat from both logging and climate change. For more Ecuadorian amphibians also see QCAZ's site AmphibiaWeb Ecuador (en Español). (KW)

    • February 4, 2010: Why have some toads, such as the cane toad (Bufo marinus) been able to spread nearly worldwide? Van Bocxlaer et al. (2010), in a paper published in this week's issue of Science, uses phylogenetic analysis to define a suite of traits that are associated with range-expansion ability in the family Bufonidae. Those traits include the presence of parotoid glands, inguinal fat bodies (for energy storage), large adult size, lack of dependence on high humidity or constant accessibility of water bodies, large clutch size, ability to lay eggs in temporal water bodies, and exotrophous larvae (obtaining food from the environment rather than requiring maternal provisioning of extensive amounts of yolk). (KW)

    • February 2, 2010: Can the Kihansi spray toad go back home? The New York Times describes conservation efforts for this Extinct in the Wild species, Nectophrynoides asperginis . This tiny toad species, which gives birth to miniscule toadlets, was discovered in 1998 living in the spray zone of a single Tanzanian waterfall. By 2000 a dam had been constructed that cut off 90% of the water, and most of the toad population died off soon thereafter. Chytrid fungus invaded and killed many of the remaining toads. In a bid to save this rare live-bearing species, scientists airlifted some survivors to zoos, where it was touch-and-go until it could be figured out how to keep them alive in captivity. This year some may be reintroduced to the wild. (KW)

    • February 1, 2010: The Center for Biological Diversity last week petitioned the California Fish and Game Commission to list all populations of mountain yellow-legged frogs (Rana muscosa, in the southern Sierra and Transverse Ranges, and Rana sierrae, in the central and northern Sierra) as endangered. Once these frogs were the most abundant amphibians in the Sierras; surveys since 1995 show that they have been extirpated from nearly 95% of 225 historically known localities. Currently only the Southern California population of Rana muscosa is listed as endangered. (KW)

    • January 25, 2010: 2010 is the International Year of Biodiversity! Amphibians are the most threatened vertebrate taxon, with at least 42% of species declining in numbers and nearly a third already threatened with extinction or lost entirely (Stuart et al. 2004). Please help conserve habitat, fund fieldwork and conservation, and become more aware of your local amphibians and the particular threats they face. (KW)

    • January 18, 2010: Was it fraud? Or the first demonstration of epigenetics? Vargas et al. (2009) takes a new look at the controversy surrounding Paul Kammerer's work on midwife toads, eighty-four years after Kammerer's suicide, and proposes a possible mechanism to account for Kammerer's results. See also Wagner's (2009) editorial in the same issue of the Journal of Experimental Zoology Part B: Molecular Development and Evolution, and Pennisi's (2009) commentary in Science.

      But see also Whittaker (1975), who found that Kammerer's results on siphon regeneration in the ascidian Ciona intestinalis were not repeatable and were probably fraudulent. Kammerer had claimed these experiments were the best proof of his theory.

      Whittaker also provided an insightful commentary in a later MBL publication: Whittaker, J. R. (1985). Paul Kammerer and the Suspect Siphons. MBL Science, published by Marine Biological Laboratory, Woods Hole, available online. (KW)

    • January 13, 2010: Behavioral thermoregulation may be an important mechanism for amphibians to resist amphibian chytrid fungus infection. Richards-Zawacki (2010) showed that wild Panamanian golden frogs (Atelopus zeteki) had elevated body temperatures during a chytridiomycosis epidemic, regardless of air temperature, and that this affected chytrid fungal infection prevalence. (KW)

    • January 4, 2010: A new paper by Weinstein (2009) discusses chytridiomycosis in a terrestrial direct-developing plethodontid salamander, Batrachoseps attenuatus. Among other findings, infected salamanders had 100% mortality when held under cool and moist conditions but shed the fungus under dry conditions similar to summer estivation. (KW)


    back to News by Year

    • December 16, 2009: AmphibiaWeb wishes you a very happy holiday season! Check out our new website usage statistics (21,517 queries/day for 2009). Please help us celebrate (and continue as a website) by including us in your holiday gift-giving. (KW)

    • December 7, 2009: A new paper on amphibian evolution (Sigurdsen and Bolt 2009) shows that salamanders and frogs share elbow morphology with the fossil caecilian Eocaecilia. In turn this synapomorphy is shared only with the Paleozoic temnospondyls, and not with lepospondyls, lending support to the monophyletic origin of lissamphibians from temnospondyls. (KW)

    • November 29, 2009: Sampling for amphibian chytrid fungus in wild Asian amphibians has not revealed much until this year, despite modeling predictions that Asia should be hospitable to chytrid. Now Goka et al. (2009) report that amphibian chytrid fungus appears to be both endemic and introduced in Japan, with high infection prevalence and unique, diverse chytrid haplotypes in native salamanders Andrias japonicus and Cynops ensicauda, as well as introduced species. (KW)

    • November 22, 2009: A new population of Rana muscosa has been discovered in the San Jacinto Wilderness, and trout removal from a creek in Angeles National Forest is helping another small population of R. muscosa. See Lewis (2009). (KW)

    • November 17, 2009: Please write the National Park Service by Saturday, November 21st, 2009, to support removal of non-native trout from lakes in Sequoia & King's Canyon National Park (U.S.A.). The scientific data are quite clear: when trout are removed, yellow-legged frog populations rebound. See Vredenburg (2004) and Knapp et al. (2007). (KW)

    • November 9, 2009: A new paper in Science has reported how chytrid fungus kills frogs. Voyles et al. (2009) show that Batrachochytrium dendrobatidis infection compromises the electrolyte transport capability of frog skin, eventually depleting blood levels of potassium and sodium to the point where the Bd-infected frog dies from cardiac arrest. (KW)