Hibernating bat species across North America face a dangerous introduced environmental pathogen, Pseudogymnoascus destructans, which causes white-nose syndrome (WNS). WNS is an imminent extinction threat to susceptible bat species found on Department of Defense installations and neighboring lands. The goal of this project was to predict the impacts of WNS and fill the critical knowledge gaps for western bat species. The objectives to meet this goal included the following: (1) collect hibernation physiological and environmental data, (2) apply a mechanistic WNS bioenergetics survivorship model to characterize species-level risk, (3) integrate the model with spatial data to evaluate future scenarios, and (4) disseminate the scientific findings.
The project team hypothesized variation in WNS mortality among hibernating species was related to species level bioenergetic traits and environmental factors and they tested the hypothesis using empirical data and bioenergetic models. In advance of WNS arrival, the team collected or compiled existing physiological data on 3073 bats, representing 13 species, across 14 sites in the West. Microclimate measurements were also compiled or collected from hibernacula. The project team evaluated these new data for inter- and intraspecific energetic profiles, conducted modeling analyses of environmental and climate factors that affect hibernation conditions, and applied the survivorship model to predict survival in the presence of WNS and future climate change.
The project has succeeded in collecting high-quality bioenergetics and environmental data on bat hibernation and has used these data to develop predictive models of WNS susceptibility in western bats. The data were the first to establish valuable pre-WNS reference points for the hibernation physiology of over a dozen western bat species. The project team did not observe significant differences in hibernation physiology within species, but they did observe significant differences of rates of evaporative water loss among species and the temperature range where minimum torpid metabolic rate is used. The mechanistically informed species distribution models allowed the project team to predict the role of WNS and changing climate on spatial survivorship of western species, including that the majority of the species studied will be negatively impacted by WNS.
This project significantly contributes to real world proactive management strategies for WNS by improving our scientific understanding of (1) which western species, (2) populations, and (3) habitats are likely to be associated with high WNS mortality. This information is central to conducting efficient and effective surveillance and monitoring across the large western landscape as well as to deploy WNS interventions and to track potential evolutionary rescue.