Physiological Consequences Of White-Nose Syndrome

White-nose syndrome (WNS) is a disease that has caused the mass mortality of hibernating bat species. Since its first discovery in the winter of 2006-2007, an estimated five million bats or more have been killed. Although infection with Pseudogymnoascus destructans (Pd, the causative agent of WNS) does not always result in death, bats that survive Pd infection may experience fitness consequences. To understand the physiological consequences of WNS, I measured reproductive rates of free-ranging hibernating bat species of the Northeastern United States. In addition, captive little brown myotis (Myotis lucifugus) bats that were infected by Pd but survived (¿WNS survivors¿) and uninfected bats were studied in order to understand the potential consequences (e.g., lower reproductive rates, decreased ability to heal wounds, degradation of wing tissue, and altered metabolic rates) of surviving WNS. No differences in reproductive rates were found between WNS-survivors and uninfected bats in either the field or in captivity. In addition, wound healing was not affected by Pd infection. However, wing tissue degradation was worse for little brown myotis 19 days post-hibernation, and mass specific metabolic rate (MSMR) was significantly higher for those infected with Pd 22 days post-hibernation. While it is clear that these consequences are a direct result of Pd infection, further research investigating the long-term consequences for both mothers and pups is necessary.

Exploration Of Survival Traits In The White-Nose Syndrome-Affected Big Brown Bat (Eptesicus Fuscus)

The widespread mortality of hibernating bats is associated with the emerging infectious disease white-nose syndrome (WNS), and has provoked a strong interest in understanding which bats will survive, and why? The ability of infected bats to resist WNS may depend upon variation in the expression of different characteristics. In a captive colony of big brown bats, I sought to characterize the phenotypic variability, repeatability, and survivability for several key ¿survival¿ traits, including: torpor patterns, microclimate preferences, and wound healing capacity. Torpor patterns were profiled using temperature sensitive dataloggers throughout the hibernation season, while microclimate preferences were quantified by using temperature-graded boxes and thermal imaging. In order to assess wound healing capacity, small wing biopsies were obtained from each bat and healing progress was tracked for one month. Individuals exhibited a wide range of phenotypes that were significantly influenced by sex and body condition. Repeatability estimates suggest that there is not a strong genetic basis for the observed variation in torpor patterns or microclimate preferences. Certain phenotypes (e.g., BMI) were associated with an increased probability of overwinter survivorship, which suggests a basis for intra-species differences in WNS susceptibility. The results from this project provide novel insight into what we know about ¿who will survive,¿ and will influence the direction and implementation of future conservation and mitigation strategies.