PATHOGENIC FUNGUS CONTRIBUTES TO AMPHIBIAN LOSSES IN THE PACIFIC-NORTHWEST

Worldwide declines in amphibian populations have been the subject of numerous recent reports, and numerous hypotheses have been constructed to address the causes. There is no evidence for a single cause for the declines. We identify and describe the spread of a pathogenic fungus that appears to be largely responsible for egg mortality in one population of western toad Bufo boreas. This is the first study documenting contemporary mortality in an amphibian population with identification of the attributed pathogenic species. The fungus we identify is circumglobally distributed and we suggest that this fungal infection could also be a major contributor to other amphibian populations declines.