Summer Populations of Northern Long-eared Bat in an Eastern Kentucky Forest Following Arrival of White-nose Syndrome

Abstract

Myotis bats have experienced significant population losses due to white-nose syndrome (WNS) throughout large portions of their distributions in eastern North America. As closed-space foragers, these species comprise an important feeding guild within eastern forests. An understanding of where summer populations remain and how their ecology has changed following impact from WNS is needed to assess fully the recovery potential of Myotis bats. We used acoustic sampling, capture surveys, radiotelemetry and roost surveys from 2015 to 2018 to evaluate the status of northern long-eared bat (Myotis septentrionalis) in an eastern Kentucky forest following region-wide impacts from WNS to this species. Acoustic activity of Myotis remained unchanged over the 4 y of sampling, with activity of these bats greatest in mid- to late July. Northern long-eared bats represented 97% of the Myotis captured, indicating activity levels likely reflected patterns for this species. We located 18 roost trees of northern long-eared bats in five tree species, including both live and dead trees. All roost trees were on upper slopes within 100 m of ridge top roads. Maximum exit counts, 24 and 21, at two roosts occurred in late May and early June, suggesting these dates represented the summer maternity period of northern long-eared bats in this forest. Our results demonstrated that post-WNS populations of northern long-eared bats on Robinson Forest formed small colonies, day-roosted in trees near roads on forested ridge tops, were reproductively active, and maintained steady levels of activity across the 4 y of sampling. These data suggest that local populations of northern long-eared bats are surviving WNS and continue to persist during summer months in forests of the Appalachian Mountain region. We hypothesize presence of ridge top roads, often associated with forest logging operations, may be important habitat elements for increasing availability of preferred roosting habitat for summer populations of northern long-eared bats in actively managed forests.