The future once looked grim for the stunning black-eyed leaf frog from Mexico and the Neotropics, but 13 years after the IUCN Red List of Threatened Species classified the species as critically endangered—often the last step before extinction—new information has led to a dramatically different classification: that it is now of least concern. According to the most recent IUCN Red List update, supported by Global Wildlife Conservation, researchers have found the animal both in historic and new locations, and in some places in high numbers, including at the GWC-funded Yal Unin Yul Witz Amphibian Reserve (or Sleeping Baby Reserve) in Guatemala.
“This lovely leaf frog is hope in a small, green-and-black package,” said Jennifer Luedtke, GWC’s manager of IUCN Red List assessments. “While so many succumb to the intensifying threats of habitat loss and disease, some amphibian species are surprising us with their resilience. Never has it been more urgent to increase our protection and support for the forests and streams they depend on to give them the best chance of survival.”
The black-eyed leaf frog is one of 212 amphibian species from Central and South America, Southeast Asia and the Caribbean whose extinction risk was evaluated by the Amphibian Specialist Group in the most recent IUCN Red List update. This information is vital for developing effective conservation measures and for prioritizing conservation resources. While the black-eyed leaf frog was the most extreme example of where new information led to a classification of a lower extinction risk, 39 other species were also similarly downlisted.
The news was not good for all species, however. Additional information about 23 species led to a classification of a higher extinction risk than previously thought. This includes the Rio Cosnipata robber frog, a Peruvian species formerly assessed as endangered and now classified as critically endangered and possibly extinct. This species was last collected and seen in 1999, despite targeted surveys in 2008, 2009 and every year since 2012. Outbreaks of the deadly amphibian pathogen chytridiomycosis have decimated other amphibian populations in the area and may also have wreaked havoc on the Rio Cosnipata robber frog.
“IUCN categories help support monitoring of wild populations and establishment of protected areas, and trigger the need to apply environmental laws to prevent extinction,” said Alessandro Catenazzi, Amphibian Red List Authority, regional coordinator for Peru. “In the specific case of species that have disappeared during disease outbreaks, such as the Rio Cosnipata robber frog, it is very important to protect habitat and continue monitoring for frog presence at known historical sites, as well as nearby areas with suitable habitat. Protecting habitat maximizes the chances that populations will be able to rebound in the future.”
Scientists once knew so little about the extinction risk of 10 of the species included in the most recent update that the IUCN Red List of Threatened Species previously considered them “data deficient.” Thanks to the hard work of a network of herpetologists in uncovering new information, these species now have new classifications: three of the species are now listed as critically endangered, four endangered, one vulnerable and two are considered least concern.
This includes the La Brea poison frog, a species now listed as critically endangered, that is known from only one location in the Pacific lowlands of Colombia. The species is difficult to detect and researchers rarely encounter it during surveys because of its small size, however several individuals were found in 2012 and 2016, which provided enough information for removing the species from the data deficient category. The primary threats to the species include illegal mining, cultivation of illegal crops and pollution. Conservationists recommend improved habitat protection to ensure that La Brea poison frog does not go extinct.
“Amphibians have the highest proportion of data deficient species of any terrestrial vertebrate group,” said Kelsey Neam, GWC’s amphibian red list officer. “This knowledge gap about their distribution, population status, or threats means the true extinction risk of these data deficient species is completely unknown. Future field work and targeted surveys are imperative for improving our understanding of these species’ risk of extinction because without more knowledge, many data deficient species are likely to go extinct without notice.”
Of the species included in the update, 29 were assessed on the IUCN Red List for the first time—14 face some level of extinction risk, while eight are considered of least concern. Not enough information is available for the remaining seven species, earning them a classification of data deficient for now.
The tropical Andes hotspot is home to the highest diversity of amphibians in the world, but unfortunately most of its amphibian species are listed as threatened on the IUCN Red List. In general, species occurring at higher elevations in the Andes are most threatened because of habitat loss and degradation (including agriculture, livestock, mining and logging), disease, invasive species (such as trout, which prey on the larvae of some amphibian species) and pollution from activities related to agriculture and mining.
The IUCN Red List is widely recognized as the most comprehensive, objective global approach for evaluating the conservation status of plant, animal and fungi species. The IUCN Red List provides conservation biologists, local communities, and even private companies with information on where species occur and in what numbers, how close those species may be to the edge of extinction, and what threats are pushing them toward that edge.
Photo: Black-eyed leaf frog (Photo by Robin Moore, Global Wildlife Conservation)