White-nose syndrome (WNS) affects cave hibernating bats throughout eastern North America and adjacent Canada. This fatal disease continues to cause mass mortality and precipitous population declines. Current morbidity estimates approach 7 million, impacting > 200 hibernacula within 30 states and five Canadian provinces.
Currently, white-nose syndrome affects at least seven species of hibernating insectivorous bats. Previously common species throughout the northeastern United States are presently at risk of regional extirpation or extinction due to white-nose syndrome (Flory et al. 2012). WNS has led to unprecedented mortality in several species of bats and may threaten more than 15 additional hibernating bat species if it continues across the continent (Flory et al. 2012).
Pseudogymnoascus destructans, the causative agent of white-nose syndrome, thrives at temperatures of 3-15 ℃ and > 90% relative humidity, conditions equivalent to bat hibernacula and bodies of hibernating bats (Foley et al. 2011). P. destructans affects bats by increasing the frequency and duration of arousals from the torpor of hibernation. Throughout the hibernation period, brief arousals to warm (euthermic) body temperatures are normal, but deplete fat stores. Typical arousal episodes span minutes or hours, with more frequent or lengthier arousal periods incurring significant energetic costs. Therefore, atypical arousal patterns due to white-nose syndrome prematurely deplete fat reserves crucial to overwinter survival.