Cave Myotis
Order Chiroptera : Family Vespertilionidae : Myotis velifer (J. A. Allen)

Description. Largest of the Myotis in Texas; hind foot large, more than half as long as tibia; ear short, reaching to or slightly beyond nostril when laid forward; upperparts uniform dull sepia; underparts much paler, tips of hairs pale cream buff. Dental formula as in M. californicus. External measurements average: total length, 90 mm; tail, 40 mm; foot, 9 mm; forearm, 42 mm.

Distribution in Texas. Occurs over most of western Texas, including South Texas, eastern portions of the Panhandle, and north-central Texas.

Habits. This species is a colonial, cave dwelling bat. They may also roost in rock crevices, old buildings, carports, under bridges, and even in abandoned cliff swallow nests. The cave myotis is the most abundant bat of the Edwards Plateau and hibernates in central Texas caves in winter. It also hibernates in the gypsum caves of the Panhandle region. The bats usually roost in clusters that may number into the thousands. Other species occasionally found with the cave myotis include big-eared bats (Plecotus), free-tailed bats (Tadarida), big brown bats (Eptesicus), Yuma myotis (Myotis), and ghost-faced bats (Mormoops). Although these bats may roost at the same site as the cave myotis, the different species usually segregate, with different bats inhabiting separate areas or rooms of the roosting site.

These bats appear shortly after sunset. They have been observed on several occasions coming into pools of water and open tanks in the late evening to drink. Their flight is fluttery and erratic, like that of other species of Myotis.

Cave myotises are opportunistic insectivores that feed on a wide variety of insects depending upon what is most available on a given night. Small moths make up the largest portion of the diet although small beetles, weevils, and antlions are also taken. Because of their larger size and stronger flight, the cave myotis may be able to forage farther abroad than other species of Myotis.

In Texas, females have been found with embryos as early as mid-April. On the Edwards Plateau, lactating females are frequently captured in May, suggesting that birth of the single young occurs in early May.

Remarks. There are two subspecies of this bat in Texas, and it is not clear where, or if, they intermingle. The subspecies are M. v. incautus in the south and M. v. magnamolaris in the northwestern part of the state.

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