Amphibian News!

April 20, 2026: DeMarchi et al (2025) explore why some amphibians are better reservoirs for the deadly chytrid fungus (Batrachochytrium dendrobatidis, Bd) than others. The authors developed a new way to measure "host competence"—a species' ability to acquire and transmit infection—by integrating susceptibility, pathogen growth, and how much pathogen is shed. Using lab experiments with three common North American amphibians (Notophthalmus viridescens, Rana clamitans, Rana catesbeiana), they found that Bd shedding increases with infection intensity, but not in a simple linear way. Instead, shedding levels off at high infection loads, challenging a common assumption in disease models. Importantly, different species achieved high competence through different pathways: eastern newts were highly susceptible, while bullfrogs shed more pathogen. These results highlight that no single trait predicts disease risk—understanding amphibian declines requires considering multiple interacting processes. (VV)

April 13, 2026: The "thermal mismatch hypothesis" or "environmental tolerance mismatch hypothesis" (ETMH) predicts that infections increase when environmental conditions favor the pathogen more than the host. A study by Duncan et al (2025) shows that differences in temperature preferences between frogs and pathogens can help explain where amphibian disease is most severe. Using distribution data for 42 Australian frog species, they estimated the thermal niches of both frogs and the chytrid fungus (Batrachochytrium dendrobatidis, or Bd), a major driver of global amphibian declines. They found that Bd prevalence was highest when frogs and the pathogen differed most in their temperature affinities, and that warmer conditions can reduce infection in warm-adapted species. This climate-based approach offers a new way to predict disease risk across landscapes using widely available occurrence data, with potential applications for amphibian conservation and disease management. (VV)

April 6, 2026: Many frog species are green and many others are brown, but it turns out the best strategy might be to be a frog that can be either green or brown. Color polymorphism (having more than one color form) can increase a populations’ chances of survival in variable environments, often by decreasing predation risk. Goutte & Boissinot (2025) investigated this hypothesis in the most widespread cryptic color polymorphism in anurans, green and brown morphs. They showed that the green and brown morphs can coexist within species over long evolutionary periods and that these lineages that can be green or brown switch habitat more frequently and have greater diversification rates than lineages that are only one color. They also identified a genetic basis for the green/brown polymorphism in a group of African grass frogs (Ptychadena), and demonstrated that it evolves under long-term balancing selection. These results are starting to reveal the mechanistic basis for multiple color morphs in frog species and provide evidence for diversification benefits that explain the pervasiveness of polymorphism at macroevolutionary scale. (Molly Womack)

March 30, 2026: Majority of the land on earth is privately owned, but our knowledge of biodiversity has traditionally focused on public land, such as national parks. Citizen science projects, however, are offering new insights into the biodiversity of private land. Gillard and Rowley (2025) use almost 500,000 frog occurrence records from the science project FrogID to investigate the value of citizen science for biodiversity sampling on private lands and better understand the importance of private land for frog conservation. They found that private land was relatively better sampled than public land by citizen scientists, with 86% of records from private lands. Private lands supported a moderately different frog diversity to public lands, and, surprisingly, frog species richness was predicted to be likely higher on private land once aridity and sampling density were considered. Private lands also supported threatened frog species, with 91% of threatened frog species in the region recorded on private land. Overall, this work highlights just how important private lands are for global biodiversity conservation. (Read more in The Conversation) (Jodi Rowley)

March 23, 2026: AmphibiaWeb has the pleasure to introduce the Herpetological Society of Singapore (HSS) with an introduction by the current president Kannan Raja: "Over the last decade, the Herpetological Society of Singapore has built and contributed towards perpetuating awareness, acceptance and understanding of Singapore's herpetofauna via two main prongs: outreach and research. As part of our outreach efforts, we conduct guided walks in many of the country's nature parks and reserves, bringing members of the public to observe and learn about our herps in their domain. Furthermore, we also organise talks and workshops with various organisations and stakeholders to raise awareness of our unique herp biodiversity. HSS contributes to improving our understanding of local reptiles and amphibians by participating in ecological surveys and conducting research across a variety of topics and areas of interest. The Society manages a Frog Call Library, Singapore's most extensive open-access library of frog calls, featuring nearly all of our native frogs and even some from the region. Started in 2019, this resource has been useful to scientists working on local frogs and has further added to our understanding of amphibian bioacoustics. HSS is also currently running Project RunOver, a nationwide herp-vehicle collision study, to identify roadkill hotspots, explore ways to mitigate road-kills, and improve local understanding of herp-based road ecology. Lastly, to support local research, we recently launched the HSS Student Grant to enable student researchers and early-career scientists to advance herpetological science and communication locally." (Kannan Raja)

March 16, 2026: Adult frogs and toads are well known for their acoustic communication and fascinating calls, but in recent decades, research has discovered tadpoles might also have something to say. Protázio et al. (2025) documented Ceratophrys joazeirensis (Caatinga Horned Frog) tadpoles producing a short, metallic click sound. Other studies have noticed sound production in other macrophagous and carnivorous tadpole species, and it appears to have evolved convergently in Ceratophrys and Gephyromantis clades. The function of these tadpole sounds is unclear but hypotheses include functions related to aggressive signalling during feeding or a defense mechanism against predation by conspecific tadpoles. The observations by the authors indicate a potential association with prey capture behavior. Their work introduces research questions to identify why tadpoles are making these sounds and whether there are more “singing” tadpoles to discover! (Molly Womack)

March 9, 2026: Neotropical poison frogs (Dendrobatoidea) are well known for their ability to navigate back to their territories after passive displacements, but the underlying sensory mechanisms remain poorly understood. Laboratory experiments suggest that dendrobatoid frogs use simple visual cues; however, larger movements in dense, visually cluttered tropical forests are likely to be more challenging. Through behavioral field experiments, Granados-Martinez et al. (2025) tested whether male Strawberry Poison Frogs (Oophaga pumilio) rely on vision for navigation in tropical forests and open areas, where these frogs naturally occur. They displaced frogs away from their territories and blocked different portions of their visual surroundings. To accurately orient toward their territory, frogs required visual information from the ground (0 - 63° above the horizon), but not from the canopy or sky. In a second experiment, researchers displaced males in forested or open areas and characterized their homing trajectories according to visual information using 360° photos. Frogs returned home faster and more successfully in open areas, where they also showed better initial orientations and lower meandering paths. Low-level visual panoramas in open areas contained more directional information than those in closed forests, indicating that differences in visual scenery across viewing directions allow easier recovery of direction. Together, these findings suggest that navigation is more challenging for poison frogs in forested environments, likely due to the challenge of extracting reliable visual information from this complex environment. Their findings highlight the importance of visual learning in amphibian navigation and shed light on the mechanisms by which frogs orient and move in natural environments. (Sofia Granados-Martinez)

March 2, 2026: Because of their famously permeable skin, frogs are especially sensitive to changes in temperature and moisture. But a study from VanBuren et al. (2025) shows that, in some frog species, skin isn’t static over the yearly seasons. The authors used museum specimens to test whether frog skin thickness changed over the course of a year. Researchers examined three frog species from the northern United States and found that skin layers were thicker in the Fall and Winter than in earlier months. The American Bullfrog, Rana (Lithobates) catesbeiana, showed widespread changes across all skin layers and body regions sampled, while the Northern Leopard Frog, R. (Lithobates) pipiens, only showed changes in certain skin layers and certain body regions. The Spring Peeper, Pseudacris crucifer, however, showed consistent skin thickness in all body regions all year round. The authors propose that this could be linked to the frogs' life cycle with skin being thinnest after winter brumation and thickening steadily in preparation for the next cold season. (Molly Womack)

February 23, 2026: Body size is a key trait ruling amphibians' response to climate change. Previous work has found amphibian species' body sizes changing in sometimes idiosyncratic or inconsistent ways relative to measured environmental changes. Fleming and Sheldon (2025) contribute to our understanding of how climate change impacts the body size of lungless salamanders (Family Plethodontidae), which are particularly sensitive to climate change owing to their reliance on cutaneous respiration. They resurveyed body size in ten plethodontid species, last sampled 60 years ago, and emphasized the importance of considering how body size responds to changes in precipitation as well as temperature in their analysis. The Virginia mountain streams they sampled comprise an elevational gradient, where temperatures increased uniformly over time, but precipitation increased primarily at higher elevations. Six species showed significant size shifts. Responses were species-specific, but warming temperatures were generally associated with smaller bodies-- especially at wetter, high-elevation sites. Possible drivers include accelerated development, elevated metabolic demands, higher mortality, or lower energy intake. Critically, these shifts may not favor persistence. For example, smaller-bodied species may have lower fecundity or be more vulnerable to dessication-- relevant, even in a generally wetter environment, given the increased frequency of extreme events, like droughts– highlighting the complex impacts of climate change. (Emma Steigerwald)

February 15, 2026: The recent description of the 9,000th amphibian species marks a remarkable milestone for biodiversity science and a testament to decades of careful fieldwork, taxonomy, and collaboration across the globe. From rainforest leaf litter to mountain streams, amphibians continue to reveal an extraordinary diversity of forms, life histories, and adaptations, reminding us how much of the natural world remains to be discovered. This achievement celebrates not only the richness of amphibian life, but also the scientists, local communities, and conservationists whose efforts make these discoveries possible-- roughly three new species are described each week since AmphibiaWeb started! At the same time, it underscores both the urgency and the opportunity of our moment: even as amphibians face unprecedented threats– the 9,000th species added to our database, Tylototriton wufengensis (Li et al 2026), is already proposed to be listed as Vulnerable-- our growing knowledge strengthens the foundation for protecting amphibians and the ecosystems they help sustain. Here at AmphibiaWeb, we declare this to be the year of the 9,000th amphibian species so keep in touch for more special events this year!

February 9, 2026: Color vision while living underground, at first glance, seems like a superfluous trait and its relaxed selection would lead to the reduction or loss of sensory organs and neural circuits involved in image and color detection. Thus caecilians have long been assumed to be blind or capable of only rudimentary light detection, reflecting their approximately 200-million-year history of fossorial life. Navarrete et al. (2025) challenges this view with both molecular and morphological analyses and show that key components of vision and color discrimination are retained in caecilians. Specifically, they identified a long-wavelength–sensitive (LWS) opsin gene in 13 caecilian species spanning multiple families and varying degrees of fossoriality and show this gene is functionally transcribed in the eye of one species. Further, they found structurally intact eyes with organized retinas, suggesting that vision may remain functionally relevant in caecilians despite their long fossorial history. One of the many puzzles they uncovered include where LWS opsin gene is expressed as it is typically expressed in cone photoreceptors (distinct from rod photoreceptors responsible for dim-light vision) but, despite exhaustive searches, the authors were unable to find conclusive evidence for the presence of cone photoreceptors in caecilian retinas. One possible explanation is that LWS opsins are expressed in rod photoreceptors, a pattern seen in other vertebrates as an adaptation for maintaining color discrimination under low-light conditions (for example, expression of the blue-sensitive opsin SWS2 in the rods of some frogs enables color vision at night). Together, their findings open new avenues for exploring how visual systems adapt to extreme light environments and unconventional lifestyles. (María José Navarrete Méndez)

February 2, 2026: A chameleon can shoot its tongue at lightning speed, but it is not a trick unique to reptiles. Many lungless salamanders (Family Plethodontidae) can do the same. Zeng et al. 2025 show that both animal clades converged on a similar solution to launch ballistic tongues. Instead of pulling on bones like most muscles do, their tongues are powered by a tubular muscle that squeezes a slender rod inside it. This mechanism converts squeezing force to sliding motion— pressing continuously along a track to launch the tongue forward. This sliding-based force transmission allows high-speed launches across a wide range of body sizes and likely facilitated the diversification of lungless salamanders. For example, high-speed videos reveal that the tongue of a newly hatched Bolitoglossa hartwegi (snout-to-vent length, 8.9 mm) accelerates at up to 5,740 m/s 2 (~590 times the force of gravity), finishing the launch within 0.6 milliseconds – faster than a neuron firing. What's remarkable is that this ballistic performance is achieved entirely with soft tissue, thanks to its geometry and timing. This discovery helps explain how vertebrate animals generate high-power movements with unremarkable tissue, and it offers engineers a new template for building compact, flexible actuators for devices across a range of sizes. (Yu Zeng)

January 26, 2026: Borneo and certain Philippine islands are home to the Limnonectes palavanensis group, frog species that exhibit one of the most advanced brood care behaviors in which the male frogs guard the eggs laid on the forest floor and later carry the hatched larvae on their backs to suitable bodies of water. The tadpoles are released into slow-flowing streams or small standing waters developing there until metamorphosis. Until now, only three closely related species of this group were known to exhibit this behaviour (L. palavanensis, L. finchi, and L. parvus). After ca. 20 years of field research in Sabah and Sarawak and an integrative analyses of the genetic, morphological and bioacoustic characters of the palavanensis group specimens, Dehling et al (2025) showed that there is an unexpectedly high diversity within this clade. A total of eight new species were newly described, all of which probably exhibit the described brood care behaviour, even though direct observations and evidence are still lacking in some cases. In addition, the exact distribution areas of the different species are still insufficiently known. Most species appear to live allopatrically in lowland rainforests. However, four species occur mainly in montane regions and have smaller, isolated ranges. Several localities are known where the parapatric distribution areas of different species, which are restricted to certain altitude zones or forest types, directly border each other. In one case, a sympatric occurrence of L. gunungensis and L. sarawakensis was even observed. In the future, this species complex will certainly be re-examined using genomic data to clarify the extent to which these species are reproductively isolated from each other or whether significant amount of gene flow between them is still detectable. (Stefan Hertwig)

January 19, 2026: Chemical communication during amphibian courtship – with males producing pheromones in specialized breeding glands – is well documented in salamanders and newts, but its role in frogs is less understood. In many Neotropical poison frog (Dendrobatidae) species, males have glandular tissue in their fingers, and some species also have black arm glands on their upper arms. Abondano Almeida et al. (2025) used histology and RNA sequencing to analyze the glandular composition and potential pheromone production in two species that develop both gland types: Hyloxalus nexipus and H. azureiventris. As expected from former studies on other dendrobatids, both species showed high expression of a known amphibian pheromone, sodefrin precursor-like factor (SPF) in their fingers. While the finger glands are composed of specialized mucus glands (a gland type known to produce SPFs), they discovered that the arm glands are structured differently: the black arm glands in both species were composed of specialized serous glands. Despite this structural difference, in H. nexipus (but not in H. azureiventris) the black arm gland exhibited highly elevated SPF gene expression – revealing a novel SPF producing gland type in anurans and a second pheromone producing gland in dendrobatids. These findings emphasize the importance as well as the complexity of chemical communication in dendrobatid reproduction. (Lisa Schulte)

January 12, 2026: Cane Toads (Rhinella marina) were introduced into northeast Australia in 1935 and have since spread across more than 1.5 million km2 of the continent. Due to their toxins, Cane Toads have caused dramatic negative impacts on native predators. Cane Toads have not yet reached Western Australia's Pilbara region, an ancient, arid landscape with many endemic species. A recent proposal has called for the removal of 100 artificial water points to create a “waterless toad containment zone” and prevent toads from invading the area, and a new study assesses the ecological consequences should they invade. Dunlop et al (2025) conducted predictive modeling of the toad invasion and predicts that without intervention, Cane Toads will colonise most of the region between 2035 and 2055, resulting in population declines of 25 native vertebrate taxa, pushing many native species towards extinction. These biodiversity losses would have flow-on cultural impacts for First Nations people and economic impacts on the region’s primary industries. Their findings strongly supports the need to act, in a relatively humane method, before Cane Toads invade this iconic landscape. (Jodi Rowley)

January 5, 2026: The anuran fossil record for Sub-Saharan Africa is sparse, with most African frog families lacking a fossil record older than the Pliocene (ca. 5 to 1.8 million years ago). Thus the geographic and environmental context in which this rich anuran fauna diversified over the last 50 million years remains poorly documented, and discoveries to fill the knowledge gap are noteworthy. Lemierre et al. (2025) report on seven isolated bones from the Early Miocene (~20 million years ago) in western Kenya, helping to fill in part of this important temporal gap. Fossil humeri were compared to existing CT-scan data of 13 neobatrachian families (representing 52 genera and 83 extant species) distributed across sub-Saharan Africa. One of the fossil humeri is assigned to Leptopelis sp. a genus commonly known as the "forest tree frogs" with 56 described species whose present distributions span much of sub-Saharan Africa. The morphology of the fossil humerus closely resembles that of Bocage's Forest Tree Frog, Leptopelis bocagii (a large, fossorial species presently distributed in southern and eastern African savannas) and West Cameroon Forest Tree Frog, L. nordequatorialis (a large, terrestrial-arboreal species from west-Central Africa), but the authors are cautious about drawing palaeoecological or palaeoenvironmental conclusions from their limited data. Their findings represent the first fossil occurrence for the family Arthroleptidae. (Rayna Bell)