Tag: amphibians

Rare frog rediscovered after 130 years

First described in 1902, Alsodes vittatus had evaded detection since then, despite multiple search efforts.

The frog Alsodes vittatus is an elusive creature – described in 1902, it managed to go undetected for more than a century. Now, after a decade of investigation, a research team has rediscovered it, in its first sighting after 130 years.

A female individual of Alsodes vittatus.

Researchers from the Laboratory of Systematics and Conservation of Herpetozoa (SyCoH) of the University of Concepción, Chile – Dr. Claudio Correa, engineer in renewable natural resources Edvin Riveros Riffo, and biologist Juan Pablo Donoso, have published their extraordinary discovery in the journal ZooKeys.

Alsodes vittatus was scientifically described in 1902 by Rodulfo Amando Philippi, a German naturalist living in Chile. French entomologist Philibert Germain had discovered the species in 1893 at the former Hacienda San Ignacio de Pemehue in La Araucanía Region, Chile, and brought three specimens to Philippi for description. Since then, no one has seen the species again, despite multiple search efforts.

A male individual of Alsodes vittatus.

Between 1995 and 2002, several researchers unsuccessfully tried to find it in the Pemehue area, at the northwestern end of the former estate. In 2015 and 2016, new expeditions led by Claudio Correa and Juan Pablo Donoso managed to locate two populations of Alsodes in the same area, but the individuals they saw lacked A. vittatus’ distinctive white or yellow stripe on the back, suggesting they likely belonged to a different species.

A male individual of Alsodes vittatus.

“The main challenge in locating it was the lack of precision in the description of its type locality,” say the researchers. “In Germain’s time, the Hacienda San Ignacio de Pemehue was an estate of enormous size, and the naturalist did not specify the exact place where he collected the specimens.”

To locate the species, Correa and his team had to reconstruct the route that Germain could have followed within the estate by studying his publications and other historical documents. In 2023 and 2024, Claudio Correa and Edvin Riveros followed the reconstructed route, entering the former estate from the southeastern end. There, they found two populations of A. vittatus in the Lolco and Portales river basins in La Araucanía region, confirming the existence of this enigmatic species after more than a century without records.

The habitat of Alsodes vittatus.

This is an important milestone for South American herpetology and the conservation of biodiversity in the southern cone. Most of the other species in the genus Alsodes are either threatened with extinction or we don’t know enough about them to assess their status, and shedding light on where and how they live is the first step in protecting them.

“The rediscovery of A. vittatus allowed us to obtain, more than a century after its description, the first biological and ecological data on the species. Field observations also indicate that this amphibian faces several significant threats and that it could be considered endangered,” the researchers warn. “In a broader context, this rediscovery demonstrates the limited biological, evolutionary and biogeographic knowledge of the amphibians that inhabit the southern cone of South America, emphasizing the urgency of their study and conservation.”

Research article:

Correa C, Riveros-Riffo E, Donoso JP (2025) Lost for more than a century: the rediscovery of Alsodes vittatus (Philippi, 1902) (Anura, Alsodidae), one of the rarest and most elusive amphibians from Chile. ZooKeys 1230: 195-212. https://doi.org/10.3897/zookeys.1230.135523

Photos by Edvin Riveros

Southernmost crocodile newt record is a threatened new species

“Exceptional discovery” for its colors, the amphibian is also the first crocodile newt species known from the Central Highlands of Vietnam.

A spectacular crocodile newt from the Central Highlands of Vietnam was just published in the international peer-reviewed open-access academic journal ZooKeys.

“It is an exceptional discovery as it is one of the most colourful species in the genus Tylototriton. This is also the first time that a crocodile newt species is recorded from the Central Highlands of Vietnam. Occurring at elevations from 1,800 to 2,300 m above sea level, this discovery sets an elevational record for the genus in the country, with former distribution ranges between 250 m and 1,740 m.”

says discoverer and first author of the study Trung My Phung.

Furthermore, the discovery by the Vietnamese-German researcher team, which was supported by the Vietnam Academy of Science and Technology and the Cologne Zoo (Germany), represents the southernmost distribution range of the genus known to date.

The habitat of the new species is located approximately 370 air km away from the nearest Tylototriton population, which makes it an important discovery in terms of evolution and zoogeography. 

The name “ngoclinhensis” refers to the type locality of the new species, Ngoc Linh Mountain. Restricted to evergreen montane forest, the Ngoc Linh Crocodile Newt is currently known only from the Ngoc Linh Nature Reserve, Kon Tum Province, in the Central Highlands of Vietnam. This is the eighth salamander taxon described from Vietnam, and is the thirty-ninth Tylototriton species officially recognized.

The newly described crocodile newt Tylototriton ngoclinhensis sp. nov.
Photo by Prof. Dr. Tao Thien Nguyen.

Crocodile newts, scientifically known as the genus Tylototriton, include nearly 40 species inhabiting montane forest areas throughout the Asian monsoon climate zone. Remarkably, 15 of these species have been described in the past five years, and there remain several unnamed taxa, which contain cryptic species that are morphologically difficult to distinguish. 

Established in 1986, Ngoc Linh Nature Reserve is a key biodiversity area for rare species like the endangered Golden-winged Laughingthrush and the Truong Son Muntjac. The Ngoc Linh Crocodile Newt certainly will represent another flagship species of this protected area and its surroundings, say the researchers.

Ngoc Linh has become a hotspot of amphibian diversity, with numerous endemic species. An earlier study – published in the Nature Conservation journal in 2022 – highlighted the extraordinary endemism rate of amphibians in the Central Highlands of Vietnam.

“[The Central Highlands is] where the highest amphibian species diversity was recorded for Vietnam, with 130 species, while also containing the highest number of regionally occurring, micro-endemic amphibians, amounting for 26 species,”

explains one of the authors of this and the present study, Prof. Dr. Truong Quang Nguyen, vice director of the Institute of Ecology and Biological Resources (IEBR), Hanoi.

Scientists identify gaps in the protection of Vietnam’s amphibians

This recent discovery is another remarkable case, “demonstrating that the Central Highlands play a special role in Vietnamese amphibian diversification and evolution,” by the words of co-author Dr. Cuong The Pham from IEBR. 

The Ngoc Linh Crocodile Newt belongs to the group of range-restricted, so-called micro-endemic species, which face the greatest risk of extinction because of their presumably small population size. Unfortunately, on top of its special zoogeographic situation and rarity, its particularly colorful appearance will likely make it highly attractive to illegal collectors.

“Therefore, this discovery is of high conservation relevance,”

says one of the corresponding authors, Prof. Dr. Tao Thien Nguyen from the Institute of Genome Research, Hanoi.

The species should be provisionally considered to be listed as Endangered on the IUCN Red List of threatened species, the researchers say. All the species of the genus Tylototriton are already listed in the Appendices of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and also in the Governmental Decree No. 84/2021/ND-CP of Vietnam. The new species thus is automatically protected under these regulations.

Now, conservation activities on site have priority, but the team is already working on breeding conservation measures, which is in line with the One Plan Approach to Conservation, developed by IUCN’s Conservation Planning Specialist Group, which combines in-situ and ex-situ efforts and various expertises for the optimum protection of a species. 

“This has already been successfully implemented for another recently discovered, micro-endemic crocodile newt species from Vietnam, Tylototriton vietnamensis, of which already more than 350 individuals could have successfully been reproduced at the Cologne Zoo in Germany and also at the Melinh Station for Biodiversity in Vietnam, which is a promising example for IUCN’s Reverse the Red campaign and the idea of the conservation zoo”,

says Prof. Dr. Thomas Ziegler, Vietnam conservation team member and coordinator from Cologne Zoo, Germany.

***

Research article:

Phung TM, Pham CT, Nguyen TQ, Ninh HT, Nguyen HQ, Bernardes M, Le ST, Ziegler T, Nguyen TT (2023) Southbound – the southernmost record of Tylototriton (Amphibia, Caudata, Salamandridae) from the Central Highlands of Vietnam represents a new species. ZooKeys 1168: 193-218. https://doi.org/10.3897/zookeys.1168.96091

***

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New frog species named after fantasy author J.R.R. Tolkien

The frog lives in the pristine streams of the Río Negro-Sopladora National Park, a protected area with thousands of hectares of almost primary forests in Ecuador.

“In a stream in the forest there lived a Hyloscirtus. Not a nasty, dirty stream, with spoor of contamination and a muddy smell, nor yet a dry, bare, sandy stream with nothing in it to perch on or to eat: it was a Hyloscirtus-stream, and that means environmental quality.”
(adapted from the opening of “The Hobbit” by J. R. R. Tolkien)

A magnificent new species of stream frog from the Andes of Ecuador was named after J. R. R. Tolkien, creator of Middle-earth and author of famous fantasy works “The Hobbit” and “The Lord of the Rings. It lives in the pristine streams of the Río Negro-Sopladora National Park, a recently declared protected area that preserves thousands of hectares of almost primary forests in southeastern Ecuador.

Stream frogs are a group of amphibians that inhabit the high Andes of Venezuela, Colombia, Ecuado, Peru, and Bolivia. Their life is closely linked to the pure rivers and streams in the mountain areas of the Andes, hence the name “stream frogs”. The adults live in the riparian vegetation, and their tadpoles develop among the rocks of the rapid waters of the rivers.

The researchers, Juan C. Sánchez-Nivicela, José M. Falcón-Reibán, and Diego F. Cisneros-Heredia, named the new frog Hyloscirtus tolkieni in honour of one of their favourite writer. JRR Tolkien, a renowned author, poet, philologist and academic, is the creator of Middle-earth and the father of fantastic works such as “The Hobbit” and “The Lord of the Rings”. The amazing colours of this new frog species reminded them of the magnificent creatures from Tolkien’s fantasy worlds. 

Expeditions carried out since 2020 in the Río Negro-Sopladora National Park in Ecuador have allowed the discovery of a large number of species yet unknown to science. A protected area since 2018, this national park, located in the south of the country, is home to large forested areas that remain unstudied.

“For weeks, we explored different areas of the Río Negro-Sopladora National Park, walking from paramo grasslands at 3,100 meters elevation to forests at 1,000 m. We found a single individual of this new species of frog, which we found impressive due to its colouration and large size.”, indicated Juan Carlos Sánchez Nivicela, associate researcher at the Museum of Zoology of the Universidad San Francisco de Quito USFQ and the National Institute of Biodiversity, and co-author of the study where the frog is described.

The Río Negro Stream Frog is easily differentiated from all its frog releatives by its appearance and unique colouration. It is relatively large (65 mm long), a greyish green back with yellow spots and black specks, and a pale pink and black iris. Its throat, belly and flanks as well as the undersides of its legs are golden yellow with large black spots and dots, and its fingers and toes have black bars and spots and broad skin stripes.

“The new species of frog has amazing colours, and it would seem that it lives in a universe of fantasies, like those created by Tolkien. The truth is that the tropical Andes are magical ecosystems where some of the most wonderful species of flora, funga, and fauna in the world are present. Unfortunately, few areas are well protected from the negative impacts caused by humans. Deforestation, unsustainable agricultural expansion, mining, invasive species, and climate changes are seriously affecting Andean biodiversity”, said Diego F. Cisneros-Heredia, director of the Museum of Zoology of the Universidad San Francisco de Quito USFQ and associate researcher of the National Institute of Biodiversity, and co-author of the study.

The species is still only known from one locality and one individual, so information is insufficient to assess its conservation status and the risk of extinction. However, the authors agree that it is urgent to establish research and monitoring actions to study its life history and ecology, as well as its population size and dynamics. In addition, they suggest exploring new sites where additional populations may exist, and assessing whether their long-term conservation is affected by any threats, such as invasive species, mining, emerging diseases, or climate change.

The description of new species is an important mechanism to support global strategies for the conservation of vulnerable environments, since it reveals the great wealth of biodiversity that is linked to countless natural resources and environmental services. For example, amphibians are important pest controllers and play vital ecological roles in the stability of nature. Unfortunately, 57% of amphibian species in Ecuador are threatened by extinction.

Research article:

Sánchez-Nivicela JC, Falcón-Reibán JM, Cisneros-Heredia DF (2023) A new stream treefrog of the genus Hyloscirtus (Amphibia, Hylidae) from the Río Negro-Sopladora National Park, Ecuador. ZooKeys 1141: 75-92. https://doi.org/10.3897/zookeys.1141.90290

Photos by Juan Carlos Sánchez-Nivicela / Archive Museo de Zoología, Universidad San Francisco de Quito

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EU responsible for extinction domino effect on frog populations

New study shows EU frogs’ legs imports put a serious risk to frogs in Southeast Asia and Eastern Europe

In Europe, frogs’ legs are mostly offered as appetizers. © Pixabay

Between 2010 and 2019, total imports of frog’s legs into the EU numbered 40.7 million kg, which equals to up to roughly 2 billion frogs. While Belgium is the main importer, France is the main consumer. These insights are part of a new study, published in the journal Nature Conservation, which found “inexplicable volatility” in the trade of frog legs and an extreme dependency of the EU on other countries to meet its demand.

Leading author Dr. Auliya of the Leibniz Institute for the Analysis of Biodiversity Change in Bonn, Germany, outlines the manifold uncertainties underlying this trade: “The international trade in frogs’ legs is a black box, whether it is the lack of species-specific trade data, which would be needed to ensure sustainability, or the large-scale mislabeling in trade and the challenges to identify species when it comes to processed, skinned and frozen frogs’ legs.”

Frogs’ legs from large ranids at a large-scale reptile collector in North Sumatra, Indonesia. Photo by Mark Auliya

Frogs have a central role in the ecosystem as insect predators – and where frogs disappear, the use of toxic pesticides increases. Hence, the frogs’ legs trade has direct consequences not only for the frogs themselves, but for biodiversity and ecosystem health as a whole. The extent to which pesticide residues in frogs’ legs are traded internationally remains unclear.

In the 1970s and 1980s, India and Bangladesh were the top suppliers of frogs’ legs to Europe, but when their wild frog populations collapsed, both countries banned exports. Since then, Indonesia has taken over as the largest supplier. In the Southeast Asian country, as now also in Turkey and Albania, large-legged frog species are dwindling in the wild, one after the other, causing a fatal domino effect for species conservation. This increasingly threatens frog populations in the supplier countries.

“The EU is by far the world’s largest importer of frogs’ legs, and large-legged species such as the crab-eating grass frog (Fejervarya cancrivora), the giant Javan frog (Limnonectes macrodon) and the East Asian bullfrog (Hoplobatrachus rugulosus) are in particular demand among supposed gourmets in Europe”, points out co-author Dr. Sandra Altherr, a biologist and wildlife trade expert of the Germany-based charity Pro Wildlife.                                         

Frozen frogs’ legs on sale in a French supermarket, August 2022. Photo by Sandra Altherr / Pro Wildlife

While commercial frog farms, like those operated in Viet Nam, may at first glance seem to be an alternative that can relieve the pressure from wild frog populations, ongoing restocking of frog farms with native species from the wild and, in the case of non-native species, such as the American bullfrog (Lithobates catesbeianus) the risk of escape, invasion and potential risk of disease spread, are serious risks for the environment.

The harvest of wild frog populations and species produced at commercial frog farms for the purpose of consumption also leaves disease control and hygiene measures by the wayside; additionally, the cross-border trade of species for consumption has led to genetic pollution and hybridization between species.  

Limnonectes blythii species complex from a large-scale collector in North Sumatra. Photo by Mark Auliya

„During the course of this study, it became clear just how difficult it is to obtain concrete data on the current international trade in frogs’ legs. Specifically, relevant data are scattered across different unconnected databases,“ the researchers write in their paper.

In the course of their review, they were not able to find any published data out whether pesticide residues and other potentially toxic substances in (processed) frogs or their legs imported into the EU have been monitored. “This in itself is shocking and in view of the situation in exporting countries and the lack of transparency and management in the application of agrochemicals and veterinary medicinal substances within commercial farms, we strongly recommend that this monitoring become an urgent near-future task for importing countries,” they write.

“The complexity of issues underlying the frogs’ legs trade is not a priority policy item for the EU,” the authors conclude. They add that a listing of the most-affected frog species under CITES, the Convention on International Trade in Endangered Species of Wild Fauna and Flora, would help to monitor trade and ensure its sustainability, and the EU as the main destination should take the lead on that.

Research article:

Auliya M, Altherr S, Nithart C, Hughes A, Bickford D (2023) Numerous uncertainties in the multifaceted global trade in frogs’ legs with the EU as the major consumer. Nature Conservation 51: 71-135. https://doi.org/10.3897/natureconservation.51.93868

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Interview with SAGE 2022 awardee Camila G. Meneses

The PhD student at University of Kansas shares about her work on the amphibians and reptiles of the Philippenes that earned her the Best Poster Award at SAGE 2022

A  specimen  of  Pseudogekko  isapa with  tail  autotomized.
Photo by Camila G Meneses.

In August 2022, Pensoft Publishers joined the 4th International Conference on Southeast Asian Gateway Evolution (SAGE 2022) in Manila, the Philippines. As a sponsor of the conference, we gave Best Talk and Best Poster awards at the event, providing a complimentary publication in a Pensoft-published journal of their choice to each of the winners. 

A month later, we are happy to present you the first claimed prize. Titled “Amphibian and reptile diversity along a ridge-to-reef elevational gradient on a small isolated oceanic island of the central Philippines”, this Annotated List of Species paper, authored by scientists at the University of Kansas, University of Oklahoma and University of the Philippines Los Banos, and published in the Check List journal, reports on the herpetofauna of Mount Guiting-Guiting Natural Park, located in the so far understudied Sibuyan Island in the Philippines. In their study, the team recorded a total of 47 species of amphibians and reptiles, including 14 new island records and one atypical occurrence of a snake species recorded for the first time from a high elevation.

Now, the first author of the study, PhD student Camila G. Meneses (University of Kansas), who was awarded at SAGE 2022 for her poster: “A New Species of Fringed Forest Gecko, Genus Luperosaurus (Squamata: Gekkonidae), from Sibuyan Island, Central Philippines” joins us for an interview, sharing some further insights into her research and recent publication.

Congratulations for your Best Poster award at SAGE 2022! Can you introduce the topic of your poster to our readers? How does it fit in the broader context of your research?

The poster is entitled “A New Species of Fringed Forest Gecko, Genus Luperosaurus (Squamata: Gekkonidae), from Sibuyan Island, Central Philippines”. We are currently describing a new species of one of the rarest endemic Philippine lizards which corresponds to the Sibuyan Island population in central Philippines.

It is a poorly understood Southeast Asian and Southwest Pacific genus Luperosaurus, known popularly as fringed geckos, wolf geckos, or flap-legged geckos, and is documented here for the first time.

In the context of my research, visualizing historical, dry land connections that were once shared among modern islands has been crucial for understanding the distribution of biodiversity in the Philippines, an archipelago in which sea level oscillations during the Pleistocene undoubtedly influenced the assembly of regionalized floras and faunas. Sibuyan Island, separated by deep-water channels from neighboring landmasses, harbors distinct communities of amphibians and reptiles, many of which are island endemics.   

Happy to see your Annotated List of Species for amphibians and reptiles from the central Philippines, which just got published in the open-access journal Check List. Can you tell us a bit more about the biodiversity of the region and what made you and your co-authors choose it for your survey?

Centers of ende­mism in the Philippine archipelago coincide with the physi­ography of the greater Pleistocene Aggregate Islands Complexes (PAICs) of Luzon, Palawan, Negros-Panay (West Visayan islands), Mindoro, Mindanao, and the Sulu Archipelago during Pliocene and Pleistocene sea level regressions according to Inger (1954) and Voris ( 2000). However, until relatively recently, little attention was paid to fully inventorying smaller islands like those in central Romblon Province. The province is not only known for its beautiful landscapes but also the seascape.

Sibuyan was identified as a focal site for this study because of its unique complex ecosystem with notable geologic history that contributed to its high endemism—oceanic origin, geographic isolation, elevational relief, and relatively intact forests. In addi­tion, Sibuyan Island presents biogeographically com­pelling questions relating to the colonization history of organisms that could only have arrived on Sibuyan by dispersing over water . 

We also considered that a comprehensive characterization of the diversity and distribution of amphibians and reptiles of Mount Guiting-Guiting would be highly desirable on the part of the local government, specifically the Protected Management Board and the regional Department of Environment and Natural Resources (Region IV-B) for future management planning. The additional informa­tion and data will strengthen their existing conservation programs, ideally by engaging local communities, wild­life managers, ecotourists, and university researchers in Romblon Province. 

What are some of the unique or unexpected challenges you encounter in doing biogeographic research? How do you tackle them?

This is my first co-led (with the late young mammalogist, James Alvarez) big expedition in the country. The most challenging aspects for us as students this time are getting funding to do ridge to reef sampling for each season (wet and dry season), the inaccessibility of the area, and the unexpected natural calamities when we are at the peak of the mountain.

Biodiversity conservation efforts often depend on cooperation with non-experts in the field and wider support within the local community. What is the most important message that you hope your research helps transmit to the general audience?

Our knowledge of the endemic species diversity in these islands is still incomplete. It is of crucial importance to continue long-term, repeated biodiversity survey efforts that utilize a multifaceted approach and integration of an independent data stream for the understanding of small islands’ species community composition. 

We encourage the conservation of  the island’s seascape and landscape (one of the well-known tourist spots in the country), and we highly encourage interested students in nearby universities to continue studying the richly biodiverse areas in the province.

Finding excitement in your work is one of the great gifts of doing what you are passionate about. What brings you the most excitement?

For me, gradually getting answers for your own questions and making new discoveries are exciting, but of course the outstanding scenery, journey, experiences, skill sets being developed, and the stories we come to create during each expedition are priceless.

Did you happen to encounter your favorite species during the field surveys in Mount Guiting-Guiting Natural Park?

Honestly, when I am studying the diversity of amphibians and reptiles of Mt. Guiting-Guiting Natural Park, I consider every species that we collect my favorite.

Each survey site brings new knowledge (i.e., new elevation site recording, morphological variation, new distribution records, varied habitat type preferences of secretive species, etc). There are observations that have not been documented for some species in previous studies (even going back over 50 years ago in Brown and Alcala field collection, or more recently in the 2012 study by Siler et al.). This is especially the case for secretive RIG island endemics of amphibian and reptile species.

However, there are three species I can definitely say are my favorites — Brachymeles dalawangdaliri, Pseudogekko isapa, and the undescribed species of Fringed Forest Gecko These are very rare and secretive species of Philippine endemic lizards that can be found, we assumed, on Romblon Island Group and nowhere else in the world. Hence, the new collections are, we can say, very highly significant.

The first two have very few museum specimens, but we were lucky enough to document and collect enough samples to redescribe both species in terms of their morphological variations and know their first ever phylogenetic placement in relation to its related congeners (see Meneses et al. 2020). The third one is our new discovery of the Fringed-forest Gecko.

Scientists identify gaps in the protection of Vietnam’s amphibians

A new study assessing the status of amphibians in Vietnam found a high level of species richness and local endemism.

As was highlighted in the foreword to the renowned WWF Greater Mekong Report 2021, written by Prof. Dr. Thomas Ziegler, Curator for Herpetology, Ichthyology, and Invertebrates, at Cologne Zoo (Köln, Germany), there is an urgent need for more studies that identify the gaps in species conservation. 

In a new scientific article, published in the open-access peer-reviewed journal Nature Conservation, Ziegler and his team present precisely such an analysis, focusing on the world’s most threatened vertebrate class: the amphibians. The share of amphibian taxa classified as threatened with extinction – 41% – is a clear indicator for the decline in global biodiversity and a warning sign for significant environmental degradation. 

Ingerophrynus galeatus. Photo by Anna Rauhaus

The scientists examined the threat status of the Vietnamese amphibians, building on the bachelor thesis of Marie Krzikowski of the University of Cologne, Germany.

One of the amphibian breeding facilities at the Cologne Zoo’s Terrarium section with offspring (larvae, eggs, terrestrial subadults) of the threatened Vietnamese Crocodile Newt (Tylototriton vietnamensis), which is successfully bred at the Zoo.

They identified 275 amphibian species known from Vietnam, noting that the number is likely to go up. The country is classified as a biodiversity hotspot, and the rate of discovering new amphibian species remains relatively high. Of these 275 species, 95 (35%) species are endemic to the country, with more than half of them reported exclusively from a single locality, which makes them especially vulnerable to extinction. Vietnam’s Central Highlands were revealed as the region with the highest species diversity (130 species), the most regionally endemic species (26 of total 67 regionally endemic species), and the most species classified as threatened by the IUCN Red List (11 species), which highlights it as a site of particular amphibian conservation concern.

Tylototriton vietnamensis. Photo by Anna Rauhaus

In terms of threat status, 50 of the 275 species recorded so far from Vietnam (18%) are classified by the International Union for Conservation of Nature (IUCN) as threatened with extinction. These include 27 endemic species. Most of them are frogs, followed by salamanders, where 60% of the listed species are classified as threatened with extinction.

Alarmingly, 13 endemic species, including two threatened species, have been recorded exclusively from unprotected areas. For two-thirds of Vietnam’s endemic amphibians, there is no conservation data available, as their IUCN Red List status is either missing or outdated.

Tylototriton ziegleri. Photo by Thomas Ziegler

According to data from the Zoological Information Management System, 29 (11%) of the total 275 species reported to occur in Vietnam are represented in global zoos, including five threatened species, with the highest diversity concentrated in zoos in Europe and North America. 

These facts, now compiled in the overview paper by Marie Krzikowski, Truong Q. Nguyen, Cuong T. Pham, Dennis Rödder, Anna Rauhaus, Minh D. Le and Thomas Ziegler, reveal for the first time some obvious gaps in conservation. Importantly, they will provide a directory to authorities, conservationists, rescue centers, and zoos, so that they can follow up with appropriate actions.

Paramesotriton deloustali. Photo by Thomas Ziegler

In particular, the conservation of microendemic species can only be addressed by organizations, NGOs or partner institutes on site, for example in the form of field work, regulatory support or protected area establishment. 

Where species are at risk of disappearing rapidly, for example, species with a very limited distribution range, the establishment of ex-situ programs by local partners in cooperation with international zoos could help, in addition to in-situ conservation measures as part of the IUCN’s One Plan Approach, which combines in-situ and ex-situ efforts and various expertises for the optimum protection of a species.

Research article:

Krzikowski M, Nguyen TQ, Pham CT, Rödder D, Rauhaus A, Le MD, Ziegler T (2022) Assessment of the threat status of the amphibians in Vietnam – Implementation of the One Plan Approach. Nature Conservation 49: 77-116. https://doi.org/10.3897/natureconservation.49.82145

Tadpoles for dinner? Indigenous community in Mexico reveals a favorite recipe for a particular frog

Tadpoles of the Sierra Juarez brook frog Duellmanohyla ignicolor are consumed in caldo de piedra in the Chinantla region, in Oaxaca, Mexico.

Stone soup (caldo de piedra) is a traditional meal from the Indigenous Chinantla region in the state of Oaxaca, Mexico. Prepared by men, it is made by placing tomato, cilantro, chili peppers, onion, raw fish, salt, and water in a jicara (a bowl made from the fruit of the calabash tree) in a hole dug near a river. Then, the ingredients are cooked by adding red hot rocks to the “pot”.

In 2019, members of the CIIDIR-Oaxaca Amphibian Ecology Laboratory visited Santa Cruz Tepetotutla in the Chinantla region as part of their continued research work in the community’s forests and streams. 

“As we observed and recorded the presence of tadpoles, our guide, Mr. Pedro Osorio-Hernández, remarked that one such tadpole was eaten in stone soup”, says Dr Edna González Bernal, one of the researchers.

Local landscape. Photo by Carlos A. Flores

Although not much attention is paid to tadpoles, they are more important than you might think. They are perfect indicators of the health of bodies of water, due to their sensitivity to changes in the aquatic environment where they develop. When tadpoles are present in a stream, river, or even a puddle, they indicate an acceptable concentration of oxygen, pH, conductivity, and temperature, or overall good dynamics of sediments and plant matter. And, above all, finding tadpoles is the easiest way to know about the presence of an amphibian species that reproduces in that site, regardless of whether or not an adult has been observed. Hence, the identification of the unique characteristics of the tadpoles of each species is an important task that is currently drawing more attention amongst scientists. 

Duellmanohyla ignicolor tadpoles. Photo by Edna González-Bernal

“For us, as Oaxacans, Don Pedro’s words were an eye-opener”, biologist Carlos A. Flores, also part of the study,  continues. “Although we knew about the tradition of stone soup, we would have never imagined that it could be prepared with tadpoles of the Sierra Juárez Brook frog (Duellmanohyla ignicolor)!”

Duellmanohyla ignicolor. Photo by Edna González-Bernal

“As scientists, we wondered: why this species and not another? Since when have these tadpoles been eaten? In what other places are tadpoles consumed and in what form? Does this consumption have a negative effect on amphibian populations?”

To answer these questions, the researchers monitored several streams in the community, collecting data on the structure of these sites, such as depth, water velocity, temperature, etc. They wanted to identify the characteristics of the habitat where the tadpoles of this little known species are found. Their research was recently published in the open-access journal ZooKeys.

The team’s primary interest in the stone soup with tadpoles was to accurately document human interaction with this amphibian species. 

“It is common in anthropological literature to document the consumption of tadpoles in Mexico, but rarely does such documentation reach the species level. Even in some ethnoherpetological works, the consumption of tadpoles is mentioned only anecdotally”, Dr González Bernal explains.  

A boy collects tadpoles. Photo by Edna González-Bernal

“We learned that these larvae tend to form schools: aggregations of several tens to hundreds of individuals. They swim on the surface of the water and move their mouths to feed on suspended particles, which may be remains of plant matter, pollen or insect parts”, she continues. 

“This behavior, as has been documented in other species, biologically implies a strategy to feed more efficiently, control body temperature, protect themselves from predators and even to encourage social interaction. At the same time, it makes it easier for humans to capture several tadpoles using nets, hats, bags or even their own hands.”

This tadpole soup is consumed during the hottest months (April and May), when people go swimming in the river. The rest of the year, it is prepared with fish. Local people described the tadpoles as having a delicious fish-like flavor.

Why do people eat these particular tadpoles? Community members remarked that, because they are found at the surface of the water, they are considered cleaner than those found at the bottom, such as the tadpoles of the the coastal toad (Incilius valliceps) and the gloomy mountain frog (Ptychohyla zophodes). In addition, the tadpoles consumed in the stone broth reach sizes of up to 5 centimeters, which makes them a better choice for the dish.

Tadpoles caught using caps. Photo by Edna González-Bernal

Is stone soup a dish that only exists in the Chinantla region? “We found that while the dish has primarily been documented in this region, it is also consumed in some Indigenous Ayuk (Mixe) municipalities,” Dr González Bernal says. 

The cooking principle itself is a technique that has been used throughout history by different cultures around the world. The particularity of the caldo de piedra lies in its preparation with tomato, cilantro, and chili peppers, as well as prawns or particular species of fish such as the bobo (Joturus prichardi).

In the case of the Sierra Juarez Brook frog’s tadpoles, the researchers concluded that since they are consumed locally and for non-commercial purposes, the species is not at risk. However, the behavior of these tadpoles and their preference for deeper water bodies make them vulnerable to being caught in large quantities.

“In the context of the global amphibian crisis, it is of utmost importance to continue increasing our knowledge about the diversity of species and above all to delve deeper into their ecology, both at the adult and larval stages. Only in this way can we gain a greater understanding of each species’ needs and develop conservation strategies that take into account the biology of species with a complex life cycle, such as amphibians”, the research team says in conclusion. 

Research article:

Flores CA, Arreortúa M, González-Bernal E (2022) Tadpole soup: Chinantec caldo de piedra and behavior of Duellmanohyla ignicolor larvae (Amphibia, Anura, Hylidae). ZooKeys 1097: 117-132. https://doi.org/10.3897/zookeys.1097.76426

Major highway in India threatens reptiles and amphibians

“Is it the road that crosses the habitat, or does the habitat cross the road?” ask scientists before agreeing that the wrong road at the wrong place is bound to cause various perils for the local wildlife, habitats and ecosystems.

“Is it the road that crosses the habitat, or does the habitat cross the road?” ask scientists at Gauhati University (Assam, India) before agreeing that the wrong road at the wrong place is bound to cause various perils for the local wildlife, habitats and ecosystems. Furthermore, some of those effects may take longer than others to identify and confirm.

This is how the research team of doctoral research fellow Somoyita Sur, Dr Prasanta Kumar Saikia and Dr Malabika Kakati Saikia decided to study roadkill along a 64-kilometre-long stretch of one of the major highways in India: the National Highway 715. 

What makes the location a particularly intriguing choice is that it is where the highway passess between the Kaziranga National Park, a UNESCO World Heritage site in Assam and the North Karbi Anglong Wildlife Sanctuary, thus tempting animals to move to and from the floodplains of Kaziranga and the hilly terrain of the Sanctuary to escape the annual floods or – on a daily basis – in search for food and mating partners.

In the beginning, they looked into various groups, including mammals, birds, reptiles, and amphibians, before realising that the death toll amongst frogs, toads, snakes and lizards was indeed tremendous, yet overlooked. Their findings were recently published in the peer-reviewed scholarly journal Nature Conservation.

“To our surprise, the death toll within that 64-kilometre stretch of the highway was indeed dramatic. We estimated that it has been over 6000 animals that have fallen under the wheels of motor vehicles within a single year. Prior to our study, similar research had focused on big charismatic species like the tiger, elephant and rhino, so when we took into account also the smaller animals: frogs, toads, snakes and lizards, the count went through the roof. Thus, we decided to make smaller species the focus of our work,”

comments Sur.

In conclusion, the scientists agree that roads and highways cannot be abandoned or prevented from construction and expansion, as they are crucial in connecting people and transporting goods and necessities. 

“Yet, we can definitely put some effort into designing and constructing them in a scientifically sound, eco-friendly and sustainable manner, so that they don’t become the bane for our ecosystems,”

the team concludes.

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Research article:

Sur S, Saikia PK, Saikia MK (2022) Speed thrills but kills: A case study on seasonal variation in roadkill mortality on National highway 715 (new) in Kaziranga-Karbi Anglong Landscape, Assam, India. In: Santos S, Grilo C, Shilling F, Bhardwaj M, Papp CR (Eds) Linear Infrastructure Networks with Ecological Solutions. Nature Conservation 47: 87-104. https://doi.org/10.3897/natureconservation.47.73036

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Follow Nature Conservation on Twitter and Facebook.

Frog with tapir-like nose found in Amazon rainforest

The people of Peru’s Comunidad Nativa Tres Esquinas have long known about a tiny, burrowing frog with a characteristically long snout. Yet, until now, this species has remained elusive to biologists.

The people of Peru’s ​​Comunidad Nativa Tres Esquinas have long known about a tiny, burrowing frog with a long snout; one local name for it is rana danta, “tapir frog” for its resemblance to the large-nosed Amazonian mammal. But until now, this frog has remained elusive to biologists. Thanks to the help of local guides, an international team of researchers was able to find the frog and give it an official scientific name and description.

It’s an example of the Amazon’s hidden diversity, and it’s important to document it to understand how important the ecosystem functions.

Michelle Thompson, researcher in the Keller Science Action Center at Chicago’s Field Museum

“These frogs are really hard to find, and that leads to them being understudied,” says Michelle Thompson, a researcher in the Keller Science Action Center at Chicago’s Field Museum and one of the authors of a study describing the frog in Evolutionary Systematics. “It’s an example of the Amazon’s hidden diversity, and it’s important to document it to understand how important the ecosystem functions.”

“Frogs of this genus are spread throughout the Amazon, but since they live underground and can’t get very far by digging, the ranges each species is distributed in are fairly small. Since we found this new species in Amazon peatland, it wouldn’t be strange for it to be restricted to this environment. Its body shape and general look seems to be adapted to the soft soil of the peatland, rather than the robust and wider shape of species in other environments,”says Germán Chávez, a researcher at Peru’s Instituto Peruano de Herpetología and the study’s first author.

Synapturanus danta. Photo provided by Field Museum

The tapir frog’s appearance is striking. “It looks like a caricature of a tapir, because it has a big blobby body with this tiny little pointy head,” says Thompson. But despite its goofy appearance, it was very difficult to find. “The frogs are tiny, about the size of a quarter, they’re like brown, they’re underground, and they’re quick,” she says. “You know these little frogs are somewhere underground, but you just don’t see them hopping around.”

But while the frogs are hard to see, they’re not hard to hear. “We just kept hearing this beep-beep-beep coming from underground, and we suspected it could be a new species of burrowing frog because there had recently been other species in its genus described,” says Thompson. “But how do we get to it?”

Local guides who were familiar with the frogs led the researchers to peatland areas– wetlands carpeted with nutrient-rich turf made of decaying plant matter. The team searched by night, when the frogs were most active. 

“After 15 to 20 minutes of digging and looking for them, I heard Michelle screaming, and to me that could only mean that she and David had found the first adult,” says Chavez.

“We could hear them underground, going beep-beep-beep, and we’d stop, turn off our lights, and dig around, and then listen for it again,” says Thompson. “After a few hours, one hopped out of his little burrow, and we were screaming, ‘Somebody grab it!’”

Synapturanus danta. Photo by Germán Chávez

In addition to finally finding adult specimens of the frogs, the team recorded their calls. “I am obsessed with recording frog calls, so I decided to record the call first and then continue digging,” says Chávez.

The researchers used the physical specimens of the frogs, along with the recordings of their calls and an analysis of the frogs’ DNA, to confirm that they were a new species. They named them Synapturanus danta– Synapturanus is the name of the genus they belong to, and danta is the local word for “tapir.”

The frogs’ burrowing behavior that made them hard to find likely makes them an important part of their peatland home. “They’re part of the underground ecosystem,” says Thompson. “They’re moving down there, they’re eating down there, they’re laying their eggs down there. They contribute to nutrient cycling and changing the soil structure.”

“Beside the important role of this new species in the food chain of its habitat, we believe that it could be an indicator of healthy peatlands,” says Chávez. “First, we have to confirm whether it’s restricted to this habitat, but its body adaptations seem to point in that direction. For instance, if the habitat is too dry, the soil would become too hard for a non-robust frog like this one to dig. This would leave our frog with far fewer chances to find a shelter and eventually, it would be hunted by a bigger predator. So I think possibilities that this frog would be a wetlands specialist are high, but still need to go further in this research to confirm it.”

Panoramic view of the type locality. Photo by Alvaro del Campo

And the study’s implications go beyond the description of one little frog. S. danta was found during a rapid inventory led by Field Museum scientists, a program in which biologists and social scientists spend a few weeks in a patch of the Amazon to learn what species live there, how the people in the area manage the land, and how they can help make a case for the area to be protected. “Even though it’s called a rapid inventory, it could take a year or more to plan these things, and then it could take a year or a decade to do the conservation follow-up,” says Thompson. “The rapid part is where you spend a month in the field. And it’s a total whirlwind.”

A view of the landscape in the Amazonian Peatlands inhabited by Synapturanus danta. Photo by Luis Montenegro

Peru’s Putumayo Basin, where this rapid inventory took place, is part of a larger conservation scheme by the Keller Science Action Center and its partners. “The Putumayo Corridor spans from Ecuador, Colombia, Peru, and down to Brazil, following the Putumayo River,” says Thompson. “There’s very little deforestation, and it’s also one of the last free flowing rivers that has no current dams. There’s like a huge conservation opportunity to conserve the whole corridor, watershed and surrounding areas. This tapir frog is another piece of evidence of why scientists and local people need to work together to protect this region.”

Research article:

Chávez G, Thompson ME, Sánchez DA, Chávez-Arribasplata JC, Catenazzi A (2022) A needle in a haystack: Integrative taxonomy reveals the existence of a new small species of fossorial frog (Anura, Microhylidae, Synapturanus) from the vast lower Putumayo basin, Peru. Evolutionary Systematics 6(1): 9-20. https://doi.org/10.3897/evolsyst.6.80281

Simplified method to survey amphibians will aid conservation

Researchers developed a method to determine which amphibians inhabit a specific area. The new technique will resolve some of the issues with conventional methods, such as capture and observational surveys.

Ryukyu Sword Tailed Newt, or Firebellied Newt. Photo by Neil Dalphin via Creative Commons CC0.

An international collaborative research group of members from seven institutions has developed a method to determine which amphibians (frogs, newts and salamanders) inhabit a specific area. Their work was published in the open-access, peer-reviewed journal Metabarcoding and Metagenomics (MBMG).

To do so, the scientists amplified and analysed extra-organismal DNA (also known as environmental DNA or eDNA) found in the water. This DNA ends up in the water after being expelled from the amphibian’s body along with mucus and excrement. 

The research group included Postdoctoral Researcher Sakata K. Masayuki and Professor Minamoto Toshifumi (Kobe University), Associate Professor Kurabayashi Atsushi (Nagahama Institute of Bio-Science and Technology), Nakamura Masatoshi (IDEA Consultants, Inc.) and Associate Professor Nishikawa Kanto (Kyoto University). 

The newly developed technique will resolve some of the issues with conventional methods, such as capture and observational surveys, which require a specialist surveyor who can visually identify species. Conventional surveys are also prone to discrepancies due to environmental factors, such as climate and season.

The researchers hope that the new method will revolutionise species monitoring, as it will enable anyone to easily monitor the amphibians that inhabit an area by collecting water samples.  

While monitoring in general is crucial to conserve the natural ecosystems, the importance of surveying amphibians is even more pressing, given the pace of their populations’ decline.

Amongst major obstacles to amphibian monitoring, however, are the facts that they are nocturnal; their young (e.g. tadpoles) and adults live in different habitats; and that specialist knowledge is required to capture individuals and identify their species. These issues make it particularly difficult to accurately survey amphibians in a standardised way, and results of individual efforts often contradict each other.

On the other hand, eDNA analysis techniques have already been established in programmes targeted at monitoring fish species, where they are already commonplace. So, the researchers behind the present study joined forces to contribute towards the development of a similar standardised analysis method for amphibians.

First of all, the researchers designed multiple methods for analysing the eDNA of amphibians and evaluated their performance to identify the most effective method. Next, they conducted parallel monitoring of 122 sites in 10 farmlands across Japan using the developed eDNA analysis along with the conventional methods (i.e. capture surveys using a net and observation surveys). 

As a result, the newly developed method was able to detect all three orders of amphibians: Caudata (the newts and salamanders), Anura (the frogs), and Gymnophiona (the caecilians). 

Furthermore, this novel eDNA analysis method was able to detect more species across all field study sites than the conventional method-based surveys, indicating its effectiveness.

Research Background

Amphibian biodiversity is continuing to decline worldwide and collecting basic information about their habitats and other aspects via monitoring is vital for conservation efforts. Traditional methods of monitoring amphibians include visual and auditory observations, and capture surveys.

However, amphibians tend to be small in size and many are nocturnal. The success of surveys varies greatly depending on the climate and season, and specialist knowledge is required to identify species. Consequently, it is difficult to monitor a wide area and assess habitats. The last decade has seen the significant development of environmental DNA analysis techniques, which can be used to investigate the distribution of a species by analysing external DNA (environmental DNA) that is released into the environment along with an organism’s excrement, mucus and other bodily fluids. 

The fundamentals of this technique involve collecting water from the survey site and analysing the eDNA contained in it to find out which species inhabit the area. In recent years, the technique has gained attention as a supplement for conventional monitoring methods. Standardised methods of analysis have already been established for other species, especially fishes, and diversity monitoring using eDNA is becoming commonplace. 

However, eDNA monitoring of amphibians is still at the development stage. One reason for this is that the proposed eDNA analysis method must be suitable for the target species or taxonomic group, and there are still issues with developing and implementing a comprehensive method for detecting amphibians. If such a method could be developed, this would make it possible for monitoring to be conducted even by people who do not have the specialised knowledge to identify species nor surveying experience.

Hopefully, this would be established as a unified standard for large-scale monitoring surveys, such as those on a national scale. This research group’s efforts to develop and evaluate analysis methods will hopefully lay the foundations for eDNA analysis to become a common tool for monitoring amphibians, as well as fish. 

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Follow Metabarcoding and Metagenomics (MBMG) journal on Twitter and Facebook.

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Research article: 

Sakata MK, Kawata MU, Kurabayashi A, Kurita T, Nakamura M, Shirako T, Kakehashi R, Nishikawa K, Hossman MY, Nishijima T, Kabamoto J, Miya M, Minamoto T (2022) Development and evaluation of PCR primers for environmental DNA (eDNA) metabarcoding of Amphibia. Metabarcoding and Metagenomics 6: e76534. https://doi.org/10.3897/mbmg.6.76534