Movement Patterns of Two Bat Species Active During Winter in the Southeastern United States

Abstract

During winter in the southeastern United States cavernicolous bats, many species of which are susceptible to white-nose syndrome, periodically arouse from torpor and occasionally leave hibernacula. We investigated the winter movements and habitat use of two bat species persisting during the white-nose syndrome epizootic, the gray bat, Myotis grisescens, and the eastern small-footed bat, M. leibii. We deployed very high frequency radio transmitters on individual bats captured outside hibernacula to investigate activity, which may include foraging, during winter. Bats were tracked from release at the cave entrance until their transmitter signal was lost or they remained stationary for >15 minutes. Gray bats (n = 12) had a core range of 1.92 km2 and an overall range of 30.93 km2. Eastern small-footed (n = 5) bats had a core range of 1.98 km2 and an overall range of 20.22 km2. Gray bats used open landcover types more than expected based on availability in the core range, but selected water and forest cover types in their overall range (P < 0.001). Eastern small-footed bats used available landcover types as expected in the core range (P = 0.1988) but selected for developed and open landcover types within the overall range (P < 0.001). Both species remained close to the hibernaculum and used roads when flying (P < 0.005), with gray bats also flying near waterways (P < 0.001). Habitat management and the enhancement of year-round prey availability adjacent to hibernacula may benefit bat populations, especially during winter when prey resources are low and bats are physiologically stressed due to hibernation and white-nose syndrome.