Description:
Corynorhinus townsendii is a medium-sized bat with enormously large, naked ears and two large lumps on its snout. Its tragus is long and slender. The pelage is long and soft, and individual hairs are uniform in color from base to tip. The dorsum usually is pale brown, and the venter is just slightly paler. The ears and membranes are brownish.
Of bats known to occur in Kansas, the only one that could be confused with Townsend's big-eared bat is Antrozous pallidus (because both species have large ears). However, the pallid bat does not have large lumps on its snout and its pelage is cream-colored rather than pale brown. Of bats that someday might be documented in Kansas but thus far have not, only Rafinesque's big-eared bat (Corynorhinus rafinesquii) might be confused with Towndend's big-eared bat. Rafinesque's big-eared bat can be distinguished by the fact that its ventral pelage is noticeable paler than its dorsal pelage and also the fact that it has hairs on its feet that extend beyond the tips of its toes.
Natural History:
This bat species does not migrate and remains in Kansas all year. In winter, both males and females hibernate individually or in small groups in relatively cold parts of caves. In summer, females form small maternity colonies in warmer areas of caves, mines, or even old buildings, whereas males remain solitary. Unlike many other species, Townsend's big-eared bats do not leave the roost to forage until it is completely dark. Their flight pattern is near the ground and generally rather rapid and twisting although they sometimes hover and flutter. Active bats can rapidly extend or contract their ears; the extended position with ears pointed forward nearly parallel to the body is assumed during flight. The tragus remains extended at all times.
Adults may attain the following dimensions: total length 95-105 mm; tail 40-50 mm; hind foot 9-16 m; ear 29-38 mm; weight 8-11 grams. These bats live from four to ten years; maximum longevity recorded is sixteen years.
Townsend's big-eared bats feed primarily by capturing insects near, or by gleaning insects from,foliage. They feed largely on small moths, although small beetles, leafhoppers, and flies also are taken. Often this species lands to feed, with the result that night roosts used frequently by this species are littered with moth wings.
Raccoons and snakes that hunt in caves and, to a lesser extent owls, evidently are the principal predators on Townsend's big-eared bat. More important sources of mortality are loss of habitat, vandalism, loss of stored fat when colonies are disturbed during hibernation, and abandoning of young when maternity colonies are disturbed by visitors.
This bat species does not migrate and remains in Kansas all year. In winter, both males and females hibernate individually or in small groups in relatively cold parts of caves. In summer, females form small maternity colonies in warmer areas of caves, mines, or even old buildings, whereas males remain solitary. Unlike many other species, Townsend's big-eared bats do not leave the roost to forage until it is completely dark. Their flight pattern is near the ground and generally rather rapid and twisting although they sometimes hover and flutter. Active bats can rapidly extend or contract their ears; the extended position with ears pointed forward nearly parallel to the body is assumed during flight. The tragus remains extended at all times.
Adults may attain the following dimensions: total length 95-105 mm; tail 40-50 mm; hind foot 9-16 m; ear 29-38 mm; weight 8-11 grams. These bats live from four to ten years; maximum longevity recorded is sixteen years.
Townsend's big-eared bats feed primarily by capturing insects near, or by gleaning insects from,foliage. They feed largely on small moths, although small beetles, leafhoppers, and flies also are taken. Often this species lands to feed, with the result that night roosts used frequently by this species are littered with moth wings.
Raccoons and snakes that hunt in caves and, to a lesser extent owls, evidently are the principal predators on Townsend's big-eared bat. More important sources of mortality are loss of habitat, vandalism, loss of stored fat when colonies are disturbed during hibernation, and abandoning of young when maternity colonies are disturbed by visitors.
Most bats of this species breed between November and February. Spermatozoa are stored in the reproductive tracts of females until spring, when ovulation, fertilization, and gestation occur. Gestation varies from 56 to 100 days, depending on temperature and length of torpor. Females awaken from hibernation and gather in small nursery colonies in May and give birth to a single pup in early June. Pups grow rapidly, are capable of flight at 3 weeks of age, and are fully weaned at 6 weeks.