Nyctinomops macrotis (Big Free-tailed Bat)

Weight: 25-30 grams

Wingspan: 42-44 centimeters


Southwestern United States, Caribbean, and Central America through northern South America.

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Ecology and Behavior:

The big free-tailed bat inhabits rocky country, where it roosts in crevices high up on cliff faces, but it has been known to roost in buildings. This bat leaves its roost late, when it is quite dark. As the species is incapable of hibernation, the northern populations are believed to be migratory. In Utah, the northern part of the distributional range of the species, individuals are present from the latter one-half of May to mid-September, but none are present in winter. This bat is a fast and powerful flier, and after the young are weaned, individuals may appear hundreds of kilometers beyond what seems to be the usual range. Records of accidental occurrence are widespread in North America, for example, there are autumn records from Iowa and British Columbia. When foraging, the big free-tailed bat usually emits a loud piercing chatter. Parasites include bat bugs and fleas.

Food Habits:

Diet consists primarily of large moths, but may include crickets, flying ants, stinkbugs, and leafhoppers.

Reproduction and Longevity:

Maternity colonies are formed by females, who give birth to one baby in June or July.

Status of Populations:

Uncommon throughout most of its range.

Text, in its original form, provided by T. L. Best, M. J. Harvey, and J. S. Altenbach. Printed spectrographs provided by M. J. O'Farrell. Distribution maps, call descriptions, and AnaMusic sound clips produced by W. L. Gannon. Accounts assembled by T. C. Sanchez-Brown.