Eastern Pipistrelle

Description:  This is one of Kentucky's two smallest bats, barely reaching 3½ inches (89 mm) in length and having a wingspan of just over 9 inches (229 mm). The fur color is variable, but typically is a reddish-brown to yellow-brown, slightly lighter on the belly. Its back fur is unique among that of Kentucky bats, being tricolored -- gray at the base, tan in the middle, and dark-tipped. The wing membranes are blackish, but the skin covering the larger wing bones, including the forearm, is flesh colored.

Range:  Widespread across the eastern United States and southern Canada, south into Central America, extending west into the central Great Plains.

Kentucky Occurrence Summary:  This bat occurs commonly across Kentucky in summer and during migration, and nearly every cave across the state harbors at least a few hibernating individuals.

Distribution in Kentucky:  See map

Habitat and Life History:  These tiny bats hibernate in a variety of sites including mines, rock shelters, and quarries, but they use caves most frequently. They hardly ever cluster, even loosely; instead they are typically found hanging singly from the ceiling or along a wall. These bats seem to prefer relatively warmer and moister portions of caves in which to hibernate. The eastern pipistrelle is somewhat migratory, and many individuals wintering in Kentucky may go farther north for the summer. Although most summer roosting sites are unknown, it is thought that the species primarily uses hollow trees and buildings. Females gather into small maternity colonies where one or two pups are born to each during June. Males probably roost in tree cavities during summer, but during spring and fall, a few individuals seem to show up just about anywhere. Pipistrelles feed entirely on minute flying insects which they capture in forest understory, along stream corridors, and along woodland edges.