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

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.

###

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.