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.
- 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 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 Biology shows 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)
- 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.
- 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.
- 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’s 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.
- 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!
- 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)
- 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.
- 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 midwestfrogs.com.
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 midwestfrogs.com. (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, 2009: 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, 2009:
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, 2009: 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, 2009: 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)
- 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)
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