Smithsonian National Museum of Natural History, North American Mammals
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  Chiroptera · Vespertilionidae · Myotis nigricans
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Myotis nigricans

Black Myotis

Order: Chiroptera
Family: Vespertilionidae

 

Conservation Status: Least Concern.


These bats are widespread throughout the Neotropics. They inhabit savannah, scrublands, and all kinds of forests, from sea level to 3,150 meters elevation. In some places they are considered pests because they can carry rabies and like to roost in buildings. When the weather is cool, females and their young cluster together. If they are under a corrugated metal roof, as the day gets hotter they move down the walls to the floor. By an hour after sunset, unless it is raining heavily, all the adults leave the roost to forage for insects. They return in the hour before sunrise, and squabble with each other for a preferred spot in the roost.

Newborn bats stay attached to their mothers for the first two or three days. After that, they are left in groups in the roost at night when the females hunt. Before they can fly, many fall victim to predators, which include opossums, cats, snakes, other bats, and even cockroaches and spiders. Others die from disease or parasites such as ticks. The young who survive fly well at 4 or 5 weeks of age and are weaned at about 5 or 6 weeks. Reproduction is timed so that weaning occurs during the rainy season, when insects are plentiful. By the time the young are three months old, they look like adults. Soon after, at about 15-17 weeks, males are reproductively active. Lifespan in the wild is at least seven years.

Length:
Range: Head and Body: 39-52 mm; Tail: 28-39 mm

Weight:
Range: 3-6 g

References:

Schinz, H.R., 1821. Das Thierreich eingetheilt nach dem Bau der Thiere als Grundlage ihrer Naturgeschichte, 1:179.

Links:

Mammal Species of the World

Mammalian Species, American Society of Mammalogists' species account

Distribution of Myotis nigricans