Natural History of the Mocha Island Ground Frog Eupsophus insularis, a Critically Endangered Species

Abstract. Eupsophus insularis inhabits a small island in the southeast Pacific, and its natural history is unknown. The species is listed as Critically Endangered based on its restricted distribution, i.e., an island under ongoing habitat deterioration. We assessed the distribution, habitat requirements, density, diet, and threats of the species with the aim of proposing strategies for its conservation. The species is restricted to a terrestrial strip 24–205 m above sea level associated with pristine temperate humid forests located in areas of low slope. A capture–recapture study indicated that its density was 15–66 individuals/ha of optimal habitat. Its diet is composed mainly of invertebrates of the humid forest floor. The high prevalence of chytrid fungus and habitat loss are important threats to the species. Herein, we present data to help with the management of the species on the island and that might help in designing more robust strategies to mitigate present and future threats.