White-nose syndrome dramatically altered the summer bat assemblage in a temperate southern Appalachian forest
White-nose syndrome (WNS), an epizootic disease caused by an invasive fungus, threatens bat populations across North America. WNS-induced changes in summer bat populations could impact functional diversity. We assessed the shift in relative abundance within an assemblage of bats in a temperate southern Appalachian forest in North Carolina and Tennessee from 2009 through 2016. We used mixed linear effects models to identify bat species signiﬁcantly impacted by WNS and those showing resistance, and to determine effects on reproductive rates for WNS-affected species. Four once-common species — the little brown bat (Myotis lucifugus), Indiana bat (M. sodalis), northern long-eared bat (M. septentrionalis), and tri-colored bat (Perimyotis subﬂavus) — showed signiﬁcant and dramatic declines (82–99%), while the big brown bat (Eptesicus fuscus), red bat (Lasiurus borealis), Raﬁnesque’s big-eared bat (Corynorhinus raﬁnesquii), and small-footed bat (M. leibii) did not decline signiﬁcantly after WNS was detected on the landscape. We detected no signiﬁcant interactions between reproductive condition and WNS period (pre- and post-arrival of the disease). Declines in summer populations mirrored declines detected in nearby winter hibernacula. Because the loss of WNS-affected bat species could negatively impact ecosystem health, it is important to monitor bat, insect, and plant community responses wherever WNS threatens bats. We hypothesize that, in the absence of small-bodied bats, there might be increases in populations of small forest pests, such as defoliating moths, as larger WNS-resistant bats may avoid or miss these small prey.