ABSTRACT
The gray bat occupies a limited distribution in limestone karst areas of the southeastern US and is listed by the US Fish and Wildlife Service as endangered. Gray bats occupy caves or cave-like environments year-round, but migrate seasonally among caves of varied temperature. Most gray bat caves can be described as hibernation, maternity, bachelor, or transitory caves. Most hibernation caves are complex, and well-defined roost stains and/or guano deposits rarely exist. The bats scatter unpredictably and periodically change roosts, often clustering in highly variable densities high above the floor. Roost stains develop slowly and conservatively indicate maximum past populations. Except in cases where multiple roosts are known to have been used simultaneously, use only the largest roost or an average from several roosts of similar size in calculating colony size in any given cave.
