Differences in sensitivity to Batrachochytrium dendrobatidis (Bd) infection across ten populations of wood frog (Lithobates sylvatica)

Background/Question/Methods

The loss of populations and extinctions of species are occurring at unprecedented rates. As part of this “biodiversity crisis,” amphibians are experiencing population declines and extinctions worldwide. Numerous factors are contributing to these declines, however disease has become one of the most prominent causes being investigated. The fungal pathogen, Batrachochytrium dendrobatidis (Bd), which causes the disease chytridiomycosis, has received extensive attention because of its worldwide distribution and its general ability to infect a diverse array of amphibian hosts.  In some systems, population declines putatively caused by Bd occur while nearby populations remain despite the presence of the pathogen.  Unfortunately, there is very little information concerning whether different populations of the same host species have differential sensitivity to Bd.  We investigated the susceptibility of newly metamorphosed wood frogs (Lithobates sylvatica) from ten different populations in standardized laboratory experiments. 

Results/Conclusions

Within each population, animals exposed to Bd showed reduced survival compared with unexposed control animals. However, survivorship differed significantly across populations suggesting that Bd differentially affects populations. Additional results will be presented regarding how pathogen loads differed across populations as well as how pathogen loads correlated with survival.  These results could yield important information on how to control the spread of Bd and reaffirm the importance of population-level conservation to protect species from Bd as well as other stressors.