Newly Discovered Sites and Potential Threats for the Critically Endangered Frog, Alsodes pehuenche, in Southern South America

VALERIA CORBALÁN; GUILLERMO DEBANDI; SOFÍA LITERAS; LEANDRO ALVAREZ; JUAN ANTONIO RIVERA; JUDIT DOPAZO; AGUSTIN ZARCO; PAULA CORNEJO; BORIS BLOTTO; JULIAN FAIVOVICH; DANIELA MASIEL

Herpetological Conservation and Biology

Herpetological Conservation and Biology

Año: 2023

1931-7603

The Pehuenche Spiny-chest Frog (Alsodes pehuenche) is a nocturnal aquatic frog that inhabits small streams and wetlands in the Central Andean Cordillera near the border between Argentina and Chile. The International Union for Conservation of Nature (IUCN) classified it as Critically Endangered (CR) due to its small extent of occurrence (EOO) and area of occupancy (AOO), as well as the continuing decline in the number of mature individuals and habitat quality due to road paving, livestock activities, and nonnative predatory fish. From March 2017 to February 2020, we conducted 11 d of research during five field trips to search for tadpoles and adults on the Argentine side of the border. We used information from local communities and satellite imagery to identify potential habitats. We found A. pehuenche individuals in 12 of the 26 sampled streams, which we grouped into three populations. These new populations extend the geographic range 6 km to the southeast and 19 km to the northeast. This increases the EOO fivefold, from 95 km2 to 497.9 km2. Nevertheless, the AOO remains small, 4.84 km2. We found individuals positive for Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis) in both new and previously known populations. We discovered salmonid fish in streams with and without frogs, and at one location we observed a Brown Trout (Salmo trutta) preying on tadpoles. The newly discovered populations face the same threats as those identified for previously known populations, except for road paving, which suggests that rapid responses are necessary to ensure the survival of the species.