These small brown bats are known for their remarkable hibernation clusters. Each bat hangs by its feet from the cave ceiling, and as many as 480 have been counted in a single square foot.
Indiana bats range throughout much of the eastern U. S. They number less than 400,000. More than 85 percent hibernate at only seven locations --tow caves and a mine in Missouri, two caves in Indiana and two caves in Kentucky.
A marked decline has been reported in Arkansas populations. Indianas no longer visit 10 caves where they previously hibernated. A Newton County cave that once contained 7,000 hibernating Indiana bats now shelters less than 200.
Currently, only eight Arkansas caves house more than 30 Indianas during their winter hibernation period (October to April). The present Arkansas population (less than 3,000) is half the 1981 size.
The total U. S. population dropped more than 34 percent since 1983. The decline is attributed to commercialization of roosting caves, killing by vandals, disturbances caused by increased numbers of spelunkers and bat banding programs, use of bats as laboratory experimental animals and possible insecticide poisoning. Some winter hibernacula are unstable as a result of blocking or impeding air flow into the caves and thereby changing the cave's climate.
One Arkansas hibernation cave was fenced by the National Park Service to protect Indiana and gray bats. Four additional hibernation caves in the Ozark National Forest and one on Buffalo National River lands are closed to the public and posted with signs to protect bat colonies. Protecting these caves may result in an increase in bat populations at these caves, but experts say it's unlikely Indiana bats will recolonize abandoned caves.
Only male Indiana bats have been found in Arkansas during summer. Females migrate northward to maternity roosts north of the Ozarks.
If you know the location of a cave that might be used by this species, please contact the Arkansas Game and Fish Commission's Nongame Mammal Program Coordinator, Blake Sasse at Blake.Sasse@agfc.ar.gov