Infection dynamics, dispersal, and adaptation: understanding the lack of recovery in a remnant frog population following a disease outbreak

Emerging infectious diseases can cause dramatic declines in wildlife populations. Sometimes these declines are followed by recovery, but many populations do not recover. Studying differential recovery patterns may yield important information for managing disease-afflicted populations and facilitating population recoveries. In the late1980s, a chytridiomycosis outbreak caused multiple frog species in Australia's Wet Tropics to decline. Populations of some species (e.g., Litoria nannotis) subsequently recovered, while others (e.g., Litoria dayi) did not. We examined the population genetics and current infection status of L. dayi, to test several hypotheses regarding the failure of its populations to recover: 1) a lack of individual dispersal abilities has prevented recolonization of previously occupied locations, 2) a loss of genetic variation has resulted in limited adaptive potential, and 3) L. dayi is currently adapting to chytridiomycosis. We found moderate to hig
h
levels of gene flo...