Predicting susceptibility to future declines in the world's frogs

ABSTRACT

The 2004 Global Amphibian Assessment demonstrated that almost 400 anuran species have recently moved closer to extinction due to a host of threat mechanisms. Of particular concern is the role of the fungal pathogen, Batrachochytrium dendrobatidis (Bd), for which more traditional conservation management is not effective. Determining which biological and environmental factors affect a species' susceptibility to these mechanisms would greatly aid conservation prioritisation and planning. We performed phylogenetic comparative analyses to determine which biological and environmental factors predict species' susceptibility to rapid declines, both generally and in the context of Bd. Our results extend the findings of previous finer scale studies: we find that high-altitude, restricted-range, aquatic species with low fecundity are most likely to suffer Bd-related declines. We use our findings to identify those species most at risk of Bd-related declines and global extinction in the future, and identify areas where many species are predicted to be susceptible. Identifying susceptible species in advance of their decline is particularly important in setting priorities when, as here, declines are hard to arrest once underway.