Gray Bat - Factors Leading To Population Decline

Factors Leading To Population Decline

The tendency of gray bats to form large colonies made the gray bat especially vulnerable to population decline due to both intentional and unintentional human disturbance. While gray bat habitat locations were always ‘patchy,’ gray bat habitats have become increasingly more isolated and fragmented with human perturbation. Suspected factors contributing to species decline include impoundment of waterways (the creation of dams, which causes flooding in former bat caves), cave commercialization, natural flooding, pesticides, water pollution and siltation, and local deforestation. All North American bat species classified as endangered or threatened by the US. Fish and Wildlife service are cave dwelling species. Of these species, the gray bat congregates in larger numbers at fewer winter hibernacula than any other North American bat. Approximately 95% of gray bats hibernate in 11 winter hibernacula, with 31% hibernating in a single cave located in northern Alabama. Because of their high population densities in appropriate habitats, gray bats serve as an important indicator species for conservation efforts.