New every week
If you know of other current amphibian-related news or papers that would be of interest here, please drop us a note.
For AmphibiaWeb's list of current papers related to amphibian declines and amphibian conservation, updated monthly by Tim Halliday, see our Recent Scientific Publications page.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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:
It’s the Year of the Salamander so it’s 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)
- 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.
- 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.
- 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.
- 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 can’t 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 S 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