Myotis velifer
cave myotis

The cave myotis is found in the south eastern tip of California, throughout the southern 2/3 of Arizona, New Mexico, and throughout all but the eastern 1/4 of Texas. The species is also found in the western half of Oklahoma and reaches barely into Kansas (Whitaker, Jr. 1980)

Within Texas there is seasonal distribution seen in this species of bat: during the summer months, these bats are found in the High Plains, Rolling Plains, Trans-Pecos, Edwards Plateau, and South Texas Plains; during the winter, the species is found in the central and north central portions of the state (Schmidly, 1991).

These are cave dwelling bats, usually roosting in large numbers. Furthermore, they will also take the opportunity to roost in a number of other areas, including crevices in rocks/walls, in old buildings, and also under bridges (Twente, 1955).

These bats are relatively large. The individuals in populations from the eastern part of the range have sepia colored fur with paler undersides, while individuals from western populations are almost black. Males are usually slightly smaller than females (Whitaker, Jr. 1980, Hill and Smith 1984).

Females usually give birth to one young each year, usually around mid-April and May. The nursery colony will break up when the adult females abandon their young at the time of weaning. They will return to the males or live in isolation until the next breeding (Hill and Smith 1984).

The pups are kept in nursery colonies with other newborns, where they are nursed and protected by adult females of the colony. These nurseries can become quite large. The young will fly when they are five weeks old (Kunz, 1995).

These bats are colonial, meaning they roost in large groups, most probably in caves. Cave myotises will hibernate in caves, using their fat reserves which are accumulated throughout the year for nutrition. The clustering behavior most probably helps the bats to stabilize their body temperature, allowing the bats to survive the period of torpidity (Schmidly, 1991).

The bats will usually appear from their roosts after sunset. They forage for insects during the night hours, and have been seen gathering at pools of water in order to drink. Flight patterns that have been observed for this species indicate erratic flight maneuvers making these bats somewhat easy to identify (Fenton, 1992).

This species sometimes form colonies with as many as 20,000 inhabitats in Kansas populations. In all but the Kansas populations, this species is migrates between summer and roosting caves. (Whitaker, Jr. 1980)

These bats are insectivorous, mainly feeding on moths. However, they will feed on anything that is available when they emerge from their roosts, including beetles, weevils, and other such insects. As a result of their large size, these bats may be able to forage further away from their roosts than other Myotis bats, thus allowing them to exploit new areas (Kunz, 1974).

These bats are invaluable to us in that they help to control the population of flying insects, which frequently harm crop outputs in all parts of the world (Fenton, 1992).

As with most bat species, these bats run the risk of carrying diseases such as rabies. Though there are very few reported cases of rabies in these bats, it usually is best to take precautions against this disease (Fenton, 1992).

No special status at the present. They are fairly well distributed (Schmidly, 1991).

Temperate North American bats are now threatened by a fungal disease called “white-nose syndrome.” This disease has devastated eastern North American bat populations at hibernation sites since 2007. The fungus, Geomyces destructans, grows best in cold, humid conditions that are typical of many bat hibernacula. The fungus grows on, and in some cases invades, the bodies of hibernating bats and seems to result in disturbance from hibernation, causing a debilitating loss of important metabolic resources and mass deaths. Mortality rates at some hibernation sites have been as high as 90%. While there are currently no reports of Myotis velifer mortalities as a result of white-nose syndrome, the disease continues to expand its range in North America. (Cryan, 2010; National Park Service, Wildlife Health Center, 2010)

There are two subspecies of this bat that are found primarily in Texas. There is not much research on whether the two subspecies cohabitate, though (Hill, 1984).