Next Species
Previous Species

Home Page

Copyright Information

  The Mammals of Texas - Online Edition

Southeastern Myotis
Order Chiroptera : Family Vespertilionidae : Myotis austroriparius Rhoads

Southeastern Myotis (Myotis austroriparius).  Photo by Merlin D. Tuttle, Bat Conservation International.Description. A small bat with dense, dull, woolly fur; upperparts brownish to sooty; fur of underparts with white tips and black bases, the general white appearance contrasting sharply with the upperparts; cranium globose and normally with a low sagittal crest. Dental formula as in M. lucifugus. External measurements average: total length, 88 mm; tail, 36 mm; foot, 9 mm; forearm, 38 mm. Weight, 5-7 g.

Species distribution mapDistribution in Texas. Southeastern United States; occurs westward to the Pineywoods region of East Texas.

Habits. M. austroriparius is predominantly a cave bat in that part of its range where suitable caves occur. But in Texas, and in most of Louisiana, it seeks out roosts in human habitations and structures. Outside of caves, it has been found in crevices between bridge timbers; in culverts and drain pipes; in boat houses, barns, and the attics of houses; and in hollow trees. The bats are usually closely associated with water and when they leave their diurnal roosts late in the evening (usually about dark), they fly to nearby ponds and streams over which they forage and from which they drink. They fly low over the water, usually within 60 cm of the surface, capturing insects. Specific foods are not known but small moths, midges, mosquitoes, and flies are probably of importance.

Where suitable caves are available, both males and females congregate in large numbers in late March and April to bear their young. In caveless areas, old buildings may serve as nursery sites. Parturition occurs in late April to late May and the young are large enough to fly 5 or 6 weeks later. The southeastern myotis is unusual among bats of the genus Myotis as it usually gives birth to twin offspring; other Myotis usually having only one young per year. At birth, the young bats weigh slightly more than 1 g each. They grow rapidly, and sexual maturity is reached in both sexes before the bats are a year old.

Their most important predators appear to be rat snakes, corn snakes, opossums, and certain species of owls. Large cockroaches may prey on newborn young that fall to the ground.

Photo credit: Merlin D. Tuttle, Bat Conservation International.