By Dan Simon

One reason for the decline of the Indiana bat is disturbances during the bats hibernation cycle.

Unlike many other bat species, which roost individually while hibernating, Indiana bats hibernate in large clusters. The result is if one bat is disturbed, it creates a ripple effect where the other bats in the cluster also become active.

For a small creature with minimal fat reserves such as a bat, these disturbances create big problems. Biologists believe each time a bat is disturbed during hibernation, it may use up as much as one tenth of its fat reserves. Only a few such incidents during the course of a long winter, can be enough to cause a cluster of bats to starve to death before the hibernation period is over.

Bats tend to favor old mines and caves for hibernation. Human visits to these sites during the winter can frequently cause the kind of disturbances mentioned above, and in at least one case, people have been accused of deliberately trying to disturb a bat colony.

Most experts believe these disturbances are the primary reason for the decline of the Indiana bat population in Pennsylvania. The mine entrances at the Canoe Creek State Park are barred and locked to prevent such disturbances, as are the entrances now to many other known bat hibernation sites in the state. Many spelunker groups (cave explorers) have pledged to stay out of caves known to house hibernating bats during the winter to also help avoid disturbing the colonies.