Kentucky Bat Working Group

Indiana Bat (Myotis sodalis)

Status: Endangered

Description: The Indiana bat is a small bat, less than 2 inches in length, with dark gray to brownish black fur. Characteristics that help distinguish it from similar species include a pinkish nose, small hind feet with sparse, short hairs that do not extend beyond the toes, and a calcar (the spur extending from the ankle) that has a slight keel. Its hair is less glossy in appearance than that of little brown bats.

Range: The Indiana bat is found throughout much of the eastern United States from Oklahoma, Iowa, and Wisconsin, east to Vermont and south to northwestern Florida.

Distribution in Kentucky: 

Habitat: For hibernation, Indiana bats prefer limestone caves with stable temperatures of 39 to 46 degrees F. As with the gray bat, few caves meet the specific roost requirements of the species. Subsequently, more than 85% of the population hibernates in only nine sites. Summer habitat requirements are not completely known for the Indiana bat. Although floodplain and riparian forests are important habitats for both foraging and roosting, other habitats are used. Indiana bats typically roost under loose bark during the summer.

Life history: Indiana bats mate in the fall and begin entering hibernation in October. Males tend to be active longer in the fall, but are hibernating by late November. During hibernation, Indiana bats cluster tightly together and, as a result, are sometimes called the social bat. Having stored sperm over the winter, female bats become pregnant soon after emergence in late March and early April. Females emerge from hibernation and migrate to summer habitats before the males. During summer, maternity colonies can be found under loose tree bark and usually consist of fewer than 100 individuals. Some males to not migrate and spend the summer near the hibernacula; others roost in similar habitats as the females but in smaller numbers. Females bear a single pup in late June or early July. Young bats are able to fly within one month after birth. Small moths are a major part of the diet of Indiana bats, but many different kinds of flying insects are taken.

Causes of decline: Decreases in Indiana bat populations have been caused by several factors. Unfortunately, most are the result of human activity. Indiana bats suffered losses in the past because humans altered cave entrances. Structures built to restrict human access to caves have also hindered the movement of bats. These structures also cause changes in air flow, temperatures, and humidity levels and make caves less suitable for bats. Human disturbance is always a factor with hibernating bats, and because Indiana bats gather together in large numbers during the winter, they are even more vulnerable to disturbance. Thousands of Indiana bats have also died at the hands of vandals. The most important hibernacula are now protected. However, Indiana bat numbers continue to decline. Some bats are lost periodically to flooding caused by natural events or human activity. Loss of forest habitat may be affecting maternity and foraging areas. As with all bats that feed primarily on insects, Indiana bats have probably suffered declines due to use of pesticides.

For additional information about Indiana bats, click on the following:

Indiana Bat - Denizen's of the Dark

University of Michigan's Animal Diversity Web - Indiana Bat

National Wildlife Federation

Ohio Division of Wildlife - Indiana Bat

Thanks to John MacGregor for providing the above photos of Indiana Bats.

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