Sex and hibernaculum temperature predict survivorship in white-nose syndrome affected little brown myotis (Myotis lucifugus).

DeeAnn M. Reeder,Laura E. Grieneisen,Sarah A. Brownlee-Bouboulis,Joseph S. Johnson

doi:10.1098/rsos.140470

Abstract

White-nose syndrome (WNS), an emerging infectious disease caused by the novel fungus Pseudogymnoascus destructans, has devastated North American bat populations since its discovery in 2006. The little brown myotis, Myotis lucifugus, has been especially affected. The goal of this 2-year captive study was to determine the impact of hibernacula temperature and sex on WNS survivorship in little brown myotis that displayed visible fungal infection when collected from affected hibernacula. In study 1, we found that WNS-affected male bats had increased survival over females and that bats housed at a colder temperature survived longer than those housed at warmer temperatures. In study 2, we found that WNS-affected bats housed at a colder temperature fared worse than unaffected bats. Our results demonstrate that WNS mortality varies among individuals, and that colder hibernacula are more favourable for survival. They also suggest that female bats may be more negatively affected by WNS than male bats, which has important implications for the long-term survival of the little brown myotis in eastern North America.

Highlights

White-nose syndrome (WNS) is an emerging infectious disease estimated to have killed over 5.7 million North American bats [1] in the 4 years following its discovery
It is caused by the psychrophilic fungus, Pseudogymnoascus destructans (Pd) [2] that grows in the skin of affected bats during periods of prolonged torpor, or hibernation [3]
Lorch et al [14], under nearly identical housing conditions, demonstrated that Pd transmission does not occur between cages, and, as visible fungal growth was not observed on the unaffected bats at any time in our study it is unlikely transmission occurred between the groups

Summary

Introduction

White-nose syndrome (WNS) is an emerging infectious disease estimated to have killed over 5.7 million North American bats [1] in the 4 years following its discovery. It is caused by the psychrophilic fungus, Pseudogymnoascus destructans (Pd) [2] that grows in the skin of affected bats during periods of prolonged torpor, or hibernation [3]. Hibernators use up to 90% of their stored energy for arousal bouts [9], in which they briefly warm up to euthermic body temperature. Sex plays a role in hibernation energetics; female bats face selective pressure to retain enough fat at the end of hibernation to ovulate upon spring emergence [10,11]

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