THE EFFECTS OF CLIMATE CHANGE AND FUNGAL DISEASE ON ANDEAN MONTANE FROGS

San Francisco State University, San Francisco CA

Investigators

Abstract

The amphibians are long-term survivors, having endured four previous planetary mass extinctions. Through these extinctions, not only did all three orders of amphibians escape extinction, but most families and genera survived. However, the global loss of biodiversity is accelerating, and amphibians are the most threatened group of vertebrates. There are many potential causes for this, but an emerging infectious disease, chytridiomycosis, caused by a highly infectious fungal pathogen, is implicated in mass die offs and extinctions worldwide. Effects of climate change on amphibian physiology has been proposed as a mechanism initiating chytridiomycosis epidemics in Central and South America on the assumption that increased temperature variability reduces amphibian immunity to fungal infection. This project will investigate whether exposure to elevated temperatures increases susceptibility to disease by measuring thermal stress and infection dynamics in frogs at a range of sites in the Peruvian Andes. This project will also delineate the historic and present distribution of the fungus in highly susceptible amphibians throughout South America. Preserved museum specimens collected at many sites throughout South America over the last 8 decades will be tested to determine if fungal pathogen emergence is coincident with collapse of amphibian populations. Available site-specific climate data from the past 5 decades will be used to evaluate whether large-scale climatic events or warming trends are associated with the emergence of this fungal pathogen and subsequent extinction of amphibian species. Results from this research will inform conservation efforts to prevent loss of amphibian species in tropical regions. Understanding the factors that contribute to outbreaks and subsequent persistence of disease in amphibian species is essential to developing strategies that can avert the loss of biodiversity and mitigate the impact of epidemics. This project will support an early career scientist, strengthen collaboration between researchers in the United States and Latin America, support the research training of a postdoctoral scholar, and provide field research experiences for two graduate students.