Indiana Bat in North Carolina

Aprilbat.pdf - April, 2000 Update to the Western North Carolina Indiana Bat Information

Status: Endangered

The following description is taken from Harvey, Michael J., BATS OF THE EASTERN UNITED STATES, Arkansas Game & Fish Commission, USFWS, Center for the Management, Utilization, and Protection of Water Resources - Tennessee Technological University, February, 1992:

 The range of the endangered Indiana bat is in the eastern U.S. from Oklahoma, Iowa, and Wisconsin east to Vermont and south to northwestern Florida. Distribution is associated with major cave regions and areas north of cave regions. The present total population is estimated at less than 400,000, with more than 85 percent hibernating at only seven locations--two caves and a mine in Missouri, two caves in Indiana, and two caves in Kentucky.

Indiana bats usually hibernate in large dense clusters of up to several thousand individuals in sections of the hibernation cave where temperatures average 38 to 43 degrees F and with relative humidities of 66 to 95 percent. They hibernate from October to April, depending on climatic conditions. Density in tightly packed clusters is usually estimated at 300 bats per square foot, although as many as 480 per square foot have been reported.

Female Indiana bats depart hibernation caves before males and arrive at summer maternity roosts in mid-May. A single offspring, born during June, is raised under loose tree bark, primarily in wooded streamside habitat. During September, they depart for hibernation caves. The summer roost of  adult males is often near maternity roosts, but where most spend the day is unknown.  Others remain near the hibernaculum. A few males are found in caves during summer.

Until recently, little was known about this bat's summer habitat and ecology.  The first maternity colony was discovered in 1974 under loose bark on a dead bitternut hickory tree in east-central Indiana. The colony, numbering about 50 individuals, also used an alternate roost under the bark of a living shagbark hickory tree. The colony's total foraging range consisted of a linear strip along approximately one-half mile of creek. Foraging habitat was confined to air space from six feet to approximately 95 feet high near foliage of streamside and floodplain trees.

Two additional colonies were discovered during subsequent summers, also in east-central Indiana. These had estimated populations of 100 and 91 respectively, including females and young. Habitat and foraging area were similar to the first colony discovered. Additional evidence gathered during recent years indicates that during summer, Indiana bats are widely dispersed in suitable habitat throughout a large portion of their range.

Through the use of radio telemetry techniques, several maternity colonies have recently been discovered and studied at several locations in Illinois. These studies reinforced the belief that floodplain forest is important habitat for Indiana bat summer populations. However, maternity populations were also located in upland habitats. It was also discovered that Indiana bats exhibited fidelity to specific roosting and foraging areas they returned to annually.

Between early August and mid-September, Indiana bats arrive near their hibernation caves and engage in swarming and mating activity. Swarming at cave entrances continues into mid or late October. During this time, fat reserves are built up for hibernation. It is thought Indiana bats feed primarily on moths. A longevity record of 13 years, 10 months for this species has been recorded.   Hibernating bats leave little evidence of their past numbers, thus it is difficult to calculate a realistic estimate of the species' overall population decline.  However, estimates at major hibernacula indicated a 34 percent decline from 1983 to 1989.

For Addtional Information, See:

IndBatBioSheet.pdf - General Indiana Bat Information

IndBatCongSheet.pdf - Western North Carolina Indiana Bat Information

Aprilbat.pdf - April, 2000 Update to the Western North Carolina Indiana Bat Information

Species Distribution from known occurrences. Species may occur in similar habitats in other counties. Species Location Map based on information provided by the North Carolina Natural Heritage Program.
For additional information regarding this Web page, contact Robert Currie, in Asheville, NC, at robert_currie@fws.gov