Defining determinants of Pseudogymnoascus destructans within hibernacula to inform surveillance and management of bat white-nose syndrome

anagement of bat white-nose syndrome remains challenging because of complex characteristics of the host, the pathogen and the ecosystems in which these organisms interact. Pseudogymnosascus destructans, the fungus that causes... [ view full abstract ]

anagement of bat white-nose syndrome remains challenging because of complex characteristics of the host, the pathogen and the ecosystems in which these organisms interact. Pseudogymnosascus destructans, the fungus that causes white-nose syndrome in bats, is known to persist within environmental substrates of bat hibernacula. In the laboratory, growth of P. destructans is highly temperature-dependent. This suggests that temperature variations within hibernacula may influence dynamics and severity of WNS by modulating loads of the fungal pathogen in the environment and on bats. However, this hypothesis remains to be tested in the field. We assessed the relative effects of spatial, temporal and temperature covariates on presence-absence and abundance of P. destructans in environmental substrates and on bats within hibernacula. Analyses were conducted in hibernacula representative of different stages of the WNS epidemic. It took approximately one year following first detection of P. destructans on bats at a hibernaculum for the fungus to accumulate to detectable levels in environmental substrates of that hibernaculum. The probability of detecting P. destructans within a hibernaculum increased significantly over time following first confirmation of WNS in bats at a site and was significantly higher in sediment compared to on wall surfaces. Overall, temperature within a hibernaculum was not an important predictor of presence or abundance of P. destructans in the environment or on bats within that environment. Overall, our results indicate that initial WNS dynamics within hibernacula are driven primarily by bats with delayed establishment of environmental reservoirs of P. destructans. This information is useful for guiding surveillance strategies and for devising management options involving decontamination or modification of hibernacula to mitigate WNS in hibernating bats.