Internal Cave Gating as a Means of Protecting Cave-Dwelling Bat Populations in Eastern Oklahoma

Of the 45 species of bats found in North America, about 18 rely substantially on caves throughout the year. Thirteen of these species are obligate cave-dwelling bats using caves year-round. They use caves as winter hibernacula, stop-over roost sites during migration, summer roost sites, or maternity sites where adult females give birth to their young. A general correlation has been made between the degree to which a species is reliant on caves during its life cycle and consideration as an endangered or threatened species by the U.S. Fish and Wildlife Service. All North American bats listed as endangered or threatened by the U.S. Fish and Wildlife Service are cave-dwelling species or subspecies (1-3). Two cave-dwelling species, the gray bat (Myotis grisescens) and Indiana Bat (Myotis sodalis), and one subspecies, the Ozark big-eared bat (Corynorhinus townsendii ingens) are of particular interest in Oklahoma. Each is federally listed as endangered by the U.S. Fish and Wildlife Service. The gray bat and the Ozark big-eared bat are both obligate, year-round cave-dwelling bats. The Indiana bat hibernates in caves in winter and disperses during non-hibernating months to form roosts under bark and in tree cavities in hardwood forests (4-6). Persistent or casual human disturbance at maternity caves and hibernacula continues to be implicated as a cause for the decline in population of most cave-dwelling bats (7-10). Disturbance at these caves may Internal Cave Gating as a Means of Protecting Cave-Dwelling Bat Populations in Eastern Oklahoma