Artículo de revista
The Population Decline and Extinction of Darwin’s Frogs
Fecha
2013Registro en:
PLoS ONE 8(6), June 2013
doi:10.1371/journal.pone.0066957
Autor
Soto Azat, Claudio
Valenzuela Sánchez, Andrés
Collen, Ben
Rowcliffe, J. Marcus
Veloso Martínez, Alberto
Cunningham, Andrew A.
Institución
Resumen
Darwin’s frogs (Rhinoderma darwinii and R. rufum) are two species of mouth-brooding frogs from Chile and Argentina. Here,
we present evidence on the extent of declines, current distribution and conservation status of Rhinoderma spp.; including
information on abundance, habitat and threats to extant Darwin’s frog populations. All known archived Rhinoderma
specimens were examined in museums in North America, Europe and South America. Extensive surveys were carried out
throughout the historical ranges of R. rufum and R. darwinii from 2008 to 2012. Literature review and location data of 2,244
archived specimens were used to develop historical distribution maps for Rhinoderma spp. Based on records of sightings,
optimal linear estimation was used to estimate whether R. rufum can be considered extinct. No extant R. rufum was found
and our modelling inferred that this species became extinct in 1982 (95% CI, 1980–2000). Rhinoderma darwinii was found in
36 sites. All populations were within native forest and abundance was highest in Chiloe´ Island, when compared with Coast,
Andes and South populations. Estimated population size and density (five populations) averaged 33.2 frogs/population
(range, 10.2–56.3) and 14.9 frogs/100 m2 (range, 5.3–74.1), respectively. Our results provide further evidence that R. rufum is
extinct and indicate that R. darwinii has declined to a much greater degree than previously recognised. Although this
species can still be found across a large part of its historical range, remaining populations are small and severely
fragmented. Conservation efforts for R. darwinii should be stepped up and the species re-classified as Endangered.