Analytic dataset informing modeling of winter species distributions of North American bat species

The fungal pathogen Pseudogymnoascus destructans and resultant white-nose
syndrome (WNS) continues to advance across North America, infecting new
bat populations, species, and hibernacula. Western North America hosts the
highest bat diversity in the U.S. and Canada, yet little is known about
hibernacula and hibernation behavior in this region. An improved
understanding of where bats hibernate and the conditions that create
suitable hibernacula is critical if land managers are to anticipate and
address the conservation needs of WNS-susceptible species in regions yet
to be infected. We estimated suitability of potential winter hibernaculum
sites across the ranges of five bat species occurring in western North
America. We estimated winter survival capacity from a mechanistic
survivorship model based on bat bioenergetics and climate conditions.
Leveraging the Google Earth Engine platform for spatial data processing,
we used boosted regression trees to relate these estimates, along with key
landscape attributes, to bat occurrence data in a hybrid
correlative-mechanistic approach. Winter survival capacity, topography,
land cover, and access to caves and mines were important predictors of
winter hibernaculum selection, but the shape and relative importance of
these relationships varied among species. This suggests that the
occurrence of bat hibernacula can, in part, be predicted from readily
mapped above-ground features, and is not only dictated by below-ground
characteristics for which spatial data are lacking. Furthermore, our
mechanistic estimate of winter survivorship was, on average, the third
strongest predictor of winter occurrence probability across focal species.
Winter distributions of North American bat species were driven by their
physiological capacity to survive winter conditions and duration in a
given location, as well as selection for topographic and other landscape
features, but in species-specific ways. The influence of winter
survivorship on several species’ distributions, the underlying influence
of climate conditions on winter survivorship, and the anticipated
influence of WNS on bats’ hibernation physiology and survivorship together
suggest that North American bat distributions may undergo future shifts as
these species are exposed to not only WNS, but climate change. We
anticipate that the models presented here may offer a valuable baseline
for assessing the potential species-level impacts of these stressors.