Data for: Summer declines of cave-dwelling Tricolored Bats

Several bat species experienced rapid population declines in the northern
United States and Canada in response to the white-nose syndrome (WNS)
epizootic. The pathogen has since spread across the United States,
including the southeast, where relatively warm temperatures may change
host–pathogen interactions. In the cave-rich Tennessee-Alabama-Georgia
(TAG) region, we examined the impacts of WNS and forest cover on the
Tricolored Bat (Perimyotis subflavus) metapopulation using a long-term
dataset of 832  cave surveys conducted in summer and winter from
2004–2022. Most bat colonies were small (<30 individuals), and bats
were more likely to be present and abundant in caves surrounded by high
percent forest cover, reiterating the importance of forest management for
bat conservation. When comparing the years before and after the pathogen
arrived in 2010–2012, bat presence and abundance during winter hibernation
did not change. This stability contrasts significant declines in other
studies, suggesting that Tricolored Bat populations respond differently to
WNS in small colonies in the TAG region. Fewer Tricolored Bats used caves
in the summer than during hibernation, but across all years, we observed
1021 Tricolored Bats in 121 caves during summer surveys. Unlike stable
winter trends, bat presence and abundance declined in the post-WNS period
in summer, when cave use is optional. This first broad geographical
analysis of summer cave use highlights a potentially important change in
bat behavior. Disease surveillance and conservation efforts that target
caves with relatively small Tricolored Bat colonies in winter and/or
summer may be important for regional population persistence of this
threatened species.