Family: Vespertilionidae, Vespertilionid Bats view all from this family
Description A large myotis. Pale brown in eastern part of range to black in western part. Fur dull; often has bare patch on midback and rather pale facial skin. Calcar not keeled. Ears reach tip of nose when extended forward. L 3 1/2-4 1/2" (90-115 mm); T 1 5/8-1 7/8" (41-49 mm); HF 3/8- 1/2" (10-12 mm); FA 1 1/2-1 7/8" (37-47 mm); E 5/8" (15-17 mm); Wt 1/4- 3/8 oz (7-12 g).
Warning Bats are susceptible to rabies, a serious viral disease that results in death if untreated. Rabid bats rarely attack humans or other animals, but bats found lying on the ground may be rabid. Never touch or pick up any bat. Stay away from any animal that seems to be acting strangely and report it to animal-control officers. If you are bitten by a possibly rabid animal, you must immediately consult a doctor for a series of injections; there is no cure once symptoms emerge.
Similar Species Yuma, Eastern Small-footed, and Western Small-footed myotises are smaller. Southwestern, Long-eared, and Fringed myotises have longer ears. Long-legged and California myotises have keeled calcar.
Breeding Mates in fall; fertilization is delayed until spring. Maternity colonies form in caves or mines or under bridges. Gestation 60-70 days. Female is upright giving birth, and the young is caught in the flight membrane as it emerges.
Habitat Arid Southwest. In summer, roosts in caves, mines, and sometimes buildings; in winter, roosts in caves.
Range Extreme se California east through much of Arizona, New Mexico, and w Texas, and north to sc Kansas.
Discussion The Cave Myotis, which feeds mostly on beetles and moths, sometimes forms very large colonies, commonly of 2,000 to 5,000 individuals, although Kansas nurseries are estimated to contain 15,000 to 20,000. In winter, these bats hibernate in tight clusters in caves, sometimes on walls or ceilings or in crevices. Nursery colonies may be located in hibernating or other caves or under bridges. Except for those in Kansas, these bats migrate between summer and winter quarters.
