The gray bat's range is concentrated in the cave regions of Arkansas, Missouri, Kentucky, Tennessee and Alabama, with occasional colonies and individuals in adjacent states. The population is estimated at more than 1.5 million; however, about 95 percent hibernate in only eight caves—two in Tennessee, three in Missouri, and one each in Kentucky, Alabama and Arkansas. This makes the population extremely vulnerable.
Gray bat numbers decreased significantly during recent decades—61 percent in Arkansas, 89 percent in Kentucky, 81 percent in Missouri and 76 percent in Tennessee and Alabama. The population is now on the upswing, though, as a result of improved breeding success due to better protection measures such as cave gates, fences and informational signs near caves.
One Arkansas hibernation cave houses about 250,000 gray bats, over 15 percent of the total population. About 150,000 gray bats occupy Arkansas caves in summer.
People who disturb hibernation and maternity colonies present one of the greatest threats. Maternity colonies won't tolerate any disturbance, especially when flightless newborn young are present. Thousands of baby bats may be dropped to their deaths or abandoned by panicked parents. If aroused during hibernation, bats increase use of stored fat reserves, and if the disturbance is intense or frequent enough, starvation may result before insects are available in spring.
Other factors in the species' decline include vandalism, cave commercialization, pesticide poisoning, natural calamities such as flooding and cave-ins, loss of caves due to inundation by man-made impoundments and possibly a reduction of insect prey over streams that have been degraded by excessive pollution and siltation.
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