Ecuadorian and British scientists have rediscovered one of the rarest amphibians of Ecuador, thought to have gone extinct more than three decades ago, the Carchi Andean Toad (Rhaebo colomai).

The Carchi Andean Toad inhabits a small region in the border area between Ecuador and Colombia. The last time a specimen was observed in Ecuador was in 1984.

An expedition in July 2017 found a small population in the Dracula Reserve, in the northwestern Andes of Ecuador. The expedition was carried out by scientists from the Laboratory of Terrestrial Zoology of University San Francisco de Quito USFQ, the Natural History Museum of London, and the Instituto Nacional de Biodiversidad INABIO.

“We found these little toads near streams of crystal clear water with lush surrounding vegetation. When we saw the first individual, we immediately knew that we were in front of a species thought extinct”, said Carolina Reyes-Puig, professor and researcher at University of San Francisco de Quito USFQ.

The Dracula Reserve is the only protected area in Ecuador that could maintain populations of this threatened species today. This reserve is managed by the Ecominga Foundation and is key for the conservation of not only amphibians but also other rare and threatened biodiversity, such as Dracula and Lepanthes orchids and Spectacled Bear.

According to The IUCN Red List of Threatened Species, a global inventory with information on the risk of extinction of biodiversity, the Carchi Andean Toad was possibly extinct in Ecuador due to the absence of records for more than 30 years and the serious destruction and fragmentation of the native forests where the species lives. In 2005, it was recorded in Colombia, but the situation in Ecuador was uncertain.

“This discovery is an incredible message of hope that some species are persisting even in the face of growing threats to their survival and confirms our mandate to protect their habitats and plan for their long-term future”, said Jennifer Luedtke, Global Coordinator of the IUCN Amphibian Red List Authority.

At the global level, amphibians face a high risk of extinction due to intense human pressure. In Ecuador only, hundreds of species are on the brink of disappearing. Causes include deforestation, environmental pollution, infectious diseases and local, regional and global climate change.

“We must remember the importance of amphibians to the planet and humans. Amphibians feed on a large number of insects and in turn are prey to birds, snakes and mammals, thus having a significant impact on ecosystem nutrient cycles. Many of those insects are pests of agricultural crops, so amphibians provide an environmental service to humans. Amphibians are important indicators of environmental health”, said Diego F. Cisneros-Heredia, director of the Laboratory of Terrestrial Zoology of the University San Francisco de Quito USFQ.

The next steps following rediscovery include the development of a monitoring programme to improve knowledge of the populations status of the Carchi Andean Toad in the Dracula Reserve and the search for other populations that may have survived in small patches of forest in surrounding areas.

More about the Carchi Andean Toad

The Carchi Andean Toad was first discovered in 1984 in the headwaters of the Baboso River and in Chical, both localities on the Andes of northern Ecuador. Sadly, it was never again found in Ecuador, despite several attempts to find him. In 2005, a small population was found in the Rio Ñambí Reserve in the department of Nariño, Colombia.

Its scientific name is Rhaebo colomai and belongs to the family Bufonidae, a group that includes all true toads.

Males are small, getting to measure 4 cm, while females are larger, able to reach 6 cm.

The Carchi Andean Toad inhabits streams and ravines surrounded by primary forest in a narrow altitudinal belt between 1100 and 1500 meters above sea level. It dwells on the ground and on low branches of shrubs and is active both night and day. Apparently, the Carchi Andean Toad has a specialized diet, feeding mainly on ants.

The Carchi Andean Toad has glands behind the head, technically called parotoid glands, which produce a yellow discharge when the toad feels threatened. It is possible that these secretions have chemicals with antimicrobial activity.

The Andean Frog Carchi is currently classified as Critically Endangered and Possibly Extinct on The IUCN Red List of Threatened Species: http://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T54462A11149772.en

Photo: Carchi Andean Toad (Rhaebo colomai) © Gabriela Bittencourt, Archive Universidad San Francisco de Quito USFQ