An Official Website of the Commonwealth of Kentucky
Virginia big-eared bat by John MacGregor
Federal Status: Endangered
Kentucky Status: Endangered
Description: The Virginia big-eared bat is a medium-sized bat, about 3½ - 4 inches long with a wingspan of about 12 inches. Characteristic features are the large ears (more than one inch long) and the presence of two large lumps (glands) on the muzzle. Virginia big-eared bats can be distinguished from Rafinesque's big-eared bats, the only similar species in Kentucky, by fur color and toe hairs. Virginia big-eared bats are pale to dark brown on the back and light brown underneath. In contrast, Rafinesque's big-eared bats are gray-brown on the back with whitish underparts. Virginia big-eared bats have short toe hairs while Rafinesque's big-eared bats have hairs that extend past the toes.
Range: Virginia big-eared bats occur in isolated populations in eastern Kentucky, eastern West Virginia, southwestern Virginia, and northwestern North Carolina.
Distribution in Kentucky: See map
Habitat and Life History: This nonmigratory bat resides in caves year round. Virginia big-eared bats prefer caves in karst regions (areas underlain with limestone bedrock and many caves and sinkholes) dominated by oak-hickory or beech-maple-hemlock forest. These bats usually hibernate in tight clusters near entrances of caves that are well-ventilated and where temperatures range from 32 to 54 degrees F. As with other bat species in Kentucky, mating occurs in fall and winter, and females store sperm over winter. Ovulation and fertilization take place in spring shortly after females arouse from hibernation. In summer, females congregate in the relatively warm parts of caves to form what are known as maternity colonies where they bear their young. It is not known where most males spend the summer. Each female gives birth to a single pup in June. Young can generally fly within three weeks. Moths are the most important prey of Virginia big-eared bats.
Causes of Decline: Human disturbance is probably the biggest factor contributing to the decline of these bats. Disturbance during hibernation causes bats to lose stored fat reserves, and repeated disturbance can cause the bats to die before spring (when insect prey are again available). If female bats are disturbed during the maternity season, they may drop their young to their deaths or the whole colony may abandon a roost for a less suitable location. And as of 2016, no Virginia big-eared bats have been documented with diagnostic signs of white-nose syndrome, though they have tested positive for the fungus that causes it.