Northern Prairie Wildlife Research Center
Human disturbance of hibernating Indiana bats by cavers, researchers, and vandals account for most of the species' decline, although deforestation and stream channelization are also factors. The role of contaminants is unclear for the Indiana bat; however, pesticides have been shown to decrease the number of many insectivorous North American bats. Natural threats to this bat include flooding of hibernacula (caves), collapse of hibernacula ceilings, and hypothermia induced by severe winters.
Since the 1990 recovery report, the Indiana population of Indiana bats has increased 18 percent. Activities such as educational posting at cave entrances and cave gating have contributed to this population increase. Two formal section 7 interagency consultations have been carried out, one with the Federal Aviation Administration on a major airport expansion project and one with the Soil Conservation Service on a flood control/stream channelization project. Both consultations resulted in no-jeopardy biological opinions, and reasonable and prudent measures suggested by the Fish and Wildlife Service to minimize incidental take were adopted.
Recovery needs include protecting hibernacula, protecting and restoring summer nursery habitat, monitoring population trends, educating the public, and continuing research on Indiana bat ecology and biology.
In FY 1991, the Indiana Department of Natural Resources received $25,182 to census Indiana bats, complete a study of overwinter weight loss in hibernating bats, and gate important hibernacula. The $24,940 provided in FY 1992 went to additional cave gating, a study of summer habitat, and preparation of a comprehensive final project report.
Department of the Army: The Army is conducting a comprehensive survey of the Indiana bat population at Fort Benjamin Harrison, Indianapolis.
Indiana Department of Natural Resources: The Department is conducting projects such as population censusing, cave management, biological studies, and summer habitat studies. Management activities (e.g., gate maintenance and educational posting) afford protection to the Indiana bat. Landowner coordination for long-term protection of another important hibernaculum is under way.
Indiana Karst Conservancy: The owner of property containing several caves, this group protects Indiana bats and coordinates with the Indiana Department of Natural Resources for visitations during population surveys. Also, group volunteers provide help in gate construction.
Original plan approved 6/1/76; revised 10/14/83.