Tag: amphibians

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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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

Pakistan’s amphibians need more research efforts and better protection

In Pakistan, amphibians have long been neglected in wildlife conservation, management decisions and research agendas. To counter this, scientists have now published the first comprehensive study on all known amphibian species in the country in the open-access scholarly journal ZooKeys. The little we currently know about the occurrence of the chytrid fungus, which has already eradicated many amphibian species globally, is a grim example of how urgent it is to acquire further information.

Amphibians are bioindicators of an ecosystem’s health and may also serve as biological control of crop and forest pests. The First Herpetological Congress, organized in 1989, presented alarming findings about the decline in amphibian populations. Currently, amphibians include the highest percentage of threatened species (>40%), as well as the highest number of data deficient species (>1500 species). The little we currently know about the occurrence of the chytrid fungus, which has already eradicated many amphibian species globally, is a grim example of how urgent it is to acquire further information.

Asian Common Toad. Photo by Herpetology Lab, Arid Agriculture University Rawalpindi

Researchers just published the first comprehensive study on all known amphibian species of Pakistan in the open-access journal ZooKeys. In it, they report 21 species from the country, providing their identification key and photographic guide. However, as many of Pakistan’s potential amphibian habitats are difficult to access and study, especially the high-altitude northern and arid western mountains, it is highly likely that a lot of species are yet to be discovered.

Burrowing Frog (in amplexus). Photo by Herpetology Lab, Arid Agriculture University Rawalpindi

In particular, the authors point out that habitats facing destruction, urbanization, pollution, unsustainable utilization and other human-caused threats need to be put on high priority, so that suitable conservation strategies can be devised. This way, amphibian populations would be better controlled with less financial, administrative, and human resources.

So far, amphibians have been excluded from all current legislative and policy decisions in the country. Likewise, they are not protected under any law. Hence, the legislation pertaining to rare and endemic species needs to be updated. Schedule III, which includes protected species, provincial and federal wildlife laws, and CITES appendices are in particular need of revision.

Common Skittering Frog. Photo by Herpetology Lab, Arid Agriculture University Rawalpindi

Currently, wildlife conservation projects in Pakistan mainly focus on carnivores, ungulates and birds. Therefore, the authors of the study propose adopting an inclusive wildlife conservation approach in Pakistan. This approach would advocate the integration of poorly documented taxa, such as amphibians, in wildlife conservation and management projects. It is by highlighting the significance of their existence and the intrinsic values of all wildlife species that local ecosystems can remain healthy in the long run.

“There is also a dire need to change social attitudes towards the appreciation and significance of amphibians in our society. This could be achieved by initiating community awareness, outreach and school classrooms, and through citizen science programs,” add the researchers.

Research article:
Rais M, Ahmed W, Sajjad A, Akram A, Saeed M, Hamid HN, Abid A (2021) Amphibian fauna of Pakistan with notes on future prospects of research and conservation. ZooKeys 1062: 157-175. https://doi.org/10.3897/zookeys.1062.66913

‘Social distancing’ saves frogs: New approach to identify individual frogs noninvasively

aitik Patel and Dr Abhijit Das of the Wildlife Institute of India came up with one of the very first non-invasive approaches to identify individual frogs using photos from their natural habitats, which are then processed with the animal recognition software HotSpotter. Their unique method is described in the open-access, peer-reviewed scientific journal Herpetozoa.

A Beautiful stream frog (Amolops formosus) in a Himalayan torrent stream
Photo by Naitik Patel

Globally, 41% amphibian species are regarded as threatened with extinction. However, when it comes to the case of India, the majority of the species falls in the Data Deficient group, according to the criteria of the International Union for Conservation of Nature‘s (IUCN) Red List of Threatened Species.

This means that we hardly have any population data for Indian amphibians, which leads to a serious conservation bottleneck, especially when you are dealing with elusive herpiles. Therefore, there is the pressing priority to obtain demographic trends to prompt and support conservation actions for endemic and habitat-dependent species.

While demographics of natural populations is best estimated with the mark-recapture technique, used in animals, where individuals have distinct body markings, such as the stripes in a tiger, the dots in a whale shark and the fingerprints in a human. In the meantime, while frogs are well known for their individual-specific markings and colour patterns, this kind of technique has never been used in amphibians, even though they have long been recognised as some of the most vulnerable animals on Earth.

On the other hand, it is hardly possible to capture and mark individual frogs in the wild. So, Naitik Patel and Dr Abhijit Das of the Wildlife Institute of India came up with one of the very first non-invasive approaches to identify individual frogs using photos from their natural habitats, which are then processed with the animal recognition software HotSpotter. Their unique method is described in the open-access, peer-reviewed scientific journal Herpetozoa.

“Capturing each frog is not possible in the field, so to address this problem, we conducted a short study on Beautiful stream frogs (Amolops formosus), a species that, just like many other amphibians, has variable body markings amongst individuals. As this species inhabits the Himalayan torrent stream, which is difficult to access, we tried our best to photograph each frog from a distance to avoid any kind of physical contact,”

explains Naitik Patel, a PhD student at the Wildlife Institute of India.

A Beautiful stream frog (Amolops formosus)
Photo by Abhijit Das

Having concluded their study with a success rate of 94.3%, the research team is hopeful that their protocol could be effectively implemented in rapid population estimation for many endangered species of frogs.

“We conducted photographic documentation to capture the unique markings of each frog, and then compared them, using computer-assisted individual identification. With this method, the number of individuals can be counted to estimate the population structure. This study is exceptional, owing to the minimal disturbance it causes to the frogs. Such a technique has rarely been tried on amphibians and is a promising method to estimate their numbers. It can also be used in citizen science projects,”

comments senior scientist Dr Abhijit Das.

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Original source:

Patel NG, Das A (2020) Shot the spots: A reliable field method for individual identification of Amolops formosus (Anura, Ranidae). Herpetozoa 33: 7-15. https://doi.org/10.3897/herpetozoa.33.e47279

New to science newts from Vietnam with an important message for Biodiversity Day 2020

A new study, published in the peer-reviewed open-access journal ZooKeys, describes two new to science species and one subspecies of crocodile newts from northern Vietnam. However, this manifestation of the incredible diversity of life hosted on our planet comes as an essential reminder of how fragile Earth’s biodiversity really is.

One of the newly discovered crocodile newt species, Tylototriton pasmansi
Photo by Cuong The Pham

In time for the International Day for Biological Diversity 2020, the date (22 May) set by the United Nations to recognise biodiversity as “the pillars upon which we build civilizations”, a new study, published in the peer-reviewed open-access journal ZooKeys, describes two new to science species and one subspecies of crocodile newts from northern Vietnam. However, this manifestation of the incredible diversity of life hosted on our planet comes as an essential reminder of how fragile Earth’s biodiversity really is.

Until recently, the Black knobby newt (Tylototriton asperrimus) was known to be a common species inhabiting a large area stretching all the way from central and southern China to Vietnam. Much like most of the other members of the genus Tylototriton, colloquially referred to as crocodile newts or knobby newts, it has been increasingly popular amongst exotic pet owners and traditional Chinese medicine practitioners. Meanwhile, authorities would not show much concern about the long-term survival of the Black knobby newt, exactly because it was found at so many diverse localities. In fact, it is still regarded as Near Threatened, according to the International Union for Conservation of Nature‘s Red List.

However, over the past decade, the increasing amount of research conducted in the region revealed that there are, in fact, many previously unknown to science species, most of which would have been assumed to be yet another population of Black knobby newts. As a result, today, the crocodile newts represent the most species-rich genus within the whole family of salamanders and newts (Salamandridae).

One of the newly discovered crocodile newt species, Tylototriton sparreboomi
Photo by Anh Van Pham

Even though this might sound like great news for Earth’s biodiversity, unfortunately, it also means that each of those newly discovered species has a much narrower distributional range, making them particularly vulnerable to habitat loss and overcollection. In fact, the actual Black knobby newt turns out to only exist within a small area in China. Coupled with the high demand of crocodile newts for the traditional Chinese medicine markets and the exotic pet trade, this knowledge spells a worrying threat of extinction for the charming 12 to 15-centimetre amphibians.

In order to help with the answer of the question of exactly how many Vietnamese species are still being mistakenly called Black knobby newt, the German-Vietnamese research team of the Cologne Zoo (Germany), the universities of Hanoi (Vietnam), Cologne and Bonn (Germany), and the Vietnam Academy of Science and Technology analysed a combination of molecular and detailed morphological characters from specimens collected from northern Vietnam. Then, they compared them with the Black knobby newt specimen from China used to originally describe the species back in 1930.

Thus, the scientists identified two species (Tylototriton pasmansi and Tylototriton sparreboomi) and one subspecies (Tylototriton pasmansi obsti) previously unknown to science, bringing the total of crocodile newt taxa known from Vietnam to seven. According to the team, their discovery also confirms northern Vietnam to be one of the regions with the highest diversity of crocodile newts.

“The taxonomic separation of a single widespread species into multiple small-ranged taxa (…) has important implications for the conservation status of the original species,”

comment the researchers.

The newly discovered crocodile newts were named in honour of the specialist on salamander chytrid fungi and co-discoverer Prof. Dr. Frank Pasmans and, sadly, the recently deceased salamander enthusiasts and experts Prof. Fritz-Jurgen Obst and Prof. Dr. Max Sparreboom.

The newly discovered crocodile newt subspecies, Tylototriton pasmansi obsti
Photo by Anh Van Pham

In light of their findings, the authors conclude that the current and “outdated” Near Threatened status of the Black knobby newt needs to be reassessed to reflect the continuous emergence of new species in recent years, as well as the “severe threats from international trade and habitat loss, which have taken place over the last decade.”

Meanwhile, thanks to the commitment to biodiversity conservation of Marta Bernardes, lead author of the study and a PhD Candidate at the University of Cologne under the supervision of senior author Prof Dr Thomas Ziegler, all crocodile newts were included in the list of internationally protected species by the Convention on International Trade in Endangered Species (CITES) last year.

Today, some of the threatened crocodile newt species from Vietnam are already kept at the Cologne Zoo as part of conservation breeding projects. Such is the case for the Ziegler’s crocodile newt (Tylototriton ziegleri), currently listed as Vulnerable on the IUCN Red List and the Vietnamese crocodile newt (Tylototriton vietnamensis), currently considered as Endangered. Fortunately, the latter has been successfully bred at Cologne Zoo and an offspring from Cologne was recently repatriated.

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Original source:

Bernardes M, Le MD, Nguyen TQ, Pham CT, Pham AV, Nguyen TT, Rödder D, Bonkowski M, Ziegler T (2020) Integrative taxonomy reveals three new taxa within the Tylototriton asperrimus complex (Caudata, Salamandridae) from Vietnam. ZooKeys 935: 121-164. https://doi.org/10.3897/zookeys.935.37138

Eleven new species of rain frogs discovered in the tropical Andes

One of the newly described species: Pristimantis chomskyi.
Its name honors Noam Chomsky, a renowned linguist from ASU.
Image by David Velalcázar, BIOWEB-PUCE.

Eleven new to science species of rain frogs are described by two scientists from the Museum of Zoology of the Pontifical Catholic University of Ecuador in the open-access journal ZooKeys. Discovered in the Ecuadorian Andes, the species are characterized in detail on the basis of genetic, morphological, bioacoustic, and ecological features.

On the one hand, the publication is remarkable because of the large number of new species of frogs. Regarding vertebrate animals, most studies only list between one and five new to science species, because of the difficulty of their collection and the copious amount of work involved in the description of each. To put it into perspective, the last time a single article dealt with a similar number of newly discovered frogs from the western hemisphere was in 2007, when Spanish scientist Ignacio de la Riva described twelve species from Bolivia.

The Rain frogs comprise a unique group lacking a tadpole stage of development. Their eggs are laid on land and hatch as tiny froglets.
Image by BIOWEB-PUCE.

On the other hand, the new paper by Nadia Paez and Dr Santiago Ron is astounding due to the fact that it comes as part of the undergraduate thesis of Nadia Paez, a former Biology student at the Pontifical Catholic University, where she was supervised by Professor Santiago Ron. Normally, such a publication would be the result of the efforts of a large team of senior scientists. Currently, Nadia Paez is a PhD student in the Department of Zoology at the University of British Columbia in Canada.

Unfortunately, amongst the findings of concern is that most of the newly described frog species are listed as either Data Deficient or Threatened with extinction, according to the criteria of the International Union for Conservation of Nature (IUCN). All of the studied amphibians appear to have very restricted geographic ranges, spanning less than 2,500 km2. To make matters worse, their habitats are being destroyed by human activities, especially cattle raising, agriculture, and mining.

Amongst the newly described species, there is the peculiar Multicolored Rain Frog, where the name refers to its outstanding color variation. Individuals vary from bright yellow to dark brown. Initially, the studied specimens were assumed to belong to at least two separate species. However, genetic data demonstrated that they represented a single, even if highly variable, species.

Variations of the Multicolored Rain Frog. Its name makes reference to the outstandingly varied colorations within the species.
Image by BIOWEB-PUCE.

The rest of the previously unknown frogs were either named after scientists, who have made significant contributions in their fields, or given the names of the places they were discovered, in order to highlight places of conservation priority.

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Original source:

Paez NB, Ron SR (2019) Systematics of Huicundomantis, a new subgenus of Pristimantis (Anura, Strabomantidae) with extraordinary cryptic diversity and eleven new species. ZooKeys868: 1-112. https://doi.org/10.3897/zookeys.868.26766.

Extraordinary treefrog discovered in the Andes of Ecuador

An adult of the newly described species, Hyloscirtus hillisi. Photo by Gustavo Pazmiño, BIOWEB Ecuador.

A new treefrog species was discovered during a two-week expedition to a remote tabletop mountain at Cordillera del Cóndor, a largely unexplored range in the eastern Andes.

“To reach the tabletop, we walked two days along a steep terrain. Then, between sweat and exhaustion, we arrived to the tabletop where we found a dwarf forest. The rivers had blackwater and the frogs were sitting along them, on branches of brown shrubs similar in color to the frogs’ own. The frogs were difficult to find, because they blended with their background,” Alex Achig, one of the field biologists who discovered the new species comments on the hardships of the expedition.

Curiously, the frog has an extraordinary, enlarged claw-like structure located at the base of the thumb. Its function is unknown, but it could be that it is used either as a defence against predators or as a weapon in fights between competing males.

Having conducted analyses of genetic and morphologic data, scientists Santiago R. Ron, Marcel Caminer, Andrea Varela, and Diego Almeida from the Catholic University of Ecuador concluded that the frog represented a previously unknown species. It was recently described in the open-access journal ZooKeys.

Unlike other frogs, the new species has a claw at the base of the thumb. Photo by Gustavo Pazmiño, BIOWEB Ecuador.

The species name, Hyloscirtus hillisi, honors Dr. David Hillis, a member of the National Academy of Sciences of the United States of America, who discovered three closely related frog species in the same genus in the 1980s, while conducting a series of field trips to the Andes of southern Ecuador. Throughout his career, Dr. Hillis has made significant contributions to the knowledge of Andean amphibians and reptiles.

Despite being newly described, Hyloscirtus hillisi is already at risk of extinction. It has a small distribution range near a large-scale mining operation carried out by a Chinese company. Habitat destruction in the region has been recently documented by the NGO Amazon Conservation.

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Original source:

Ron SR, Caminer MA, Varela-Jaramillo A, Almeida-Reinoso D (2018) A new treefrog from Cordillera del Cóndor with comments on the biogeographic affinity between Cordillera del Cóndor and the Guianan Tepuis (Anura, Hylidae, Hyloscirtus). ZooKeys 809: 97-124. https://doi.org/10.3897/zookeys.809.25207

A metamorph of the new species, Hyloscirtus hillisi. Photo by Darwin Núñez, BIOWEB Ecuador.