The Ozark big-eared bat is an endangered species found only in a small number of caves in Arkansas, Oklahoma and Missouri, the southern central United States. Also known as the western big-eared bat, the long-eared bat, and the lump-nosed bat, its appearance is defined by a pair of outsize ears and a lump-adorned nose.The Ozark big-eared bat is the largest and reddest of the five subspecies of Corynorhinus townsendii and is medium-sized and weighs from 0.2 to 0.5 ounces. It has very large, 1-inch-long ears that connect at the base across the forehead. The snout has large, prominent lumps above the nostrils. These particular bats feed on moths and other insects; they forage along forest edges.
The caves used by Ozark big-eared bats are located in karst regions dominated by oak-hickory forests. Karst, a special type of landscape, is formed by the dissolution of soluble rocks, including limestone and dolomite. The temperature of hibernation caves ranges from 40 to 50 °F (4.4 to 10 °C). The Ozark big-eared bats use caves all year around, thus they are highly susceptible to extinction if their homes vary too greatly in temperature, are disturbed, or are destroyed. The Ozark big-eared bats once lived in caves in Missouri, Arkansas, and Oklahoma,. but they have apparently abandoned their Missouri habitat due to human encroachment and cave disturbance.
Concern about the conservation status of bats is developing, as many species of bats are increasingly affected by humans. Bats face multiple threats of pesticide poisoning, roost destruction and closure, habitat loss, diseases such as white nose syndrome, over-exploitation, and extermination as pests. Habitat fragmentation, a major concern, creates a disruption of extensive habitats into bat populations. The primary cause of decline is disturbance. When humans enter hibernation caves, they arouse the bats, whose metabolic rate increases. A single arousal can expend 10 to 30 days of fat reserve. This can result in death by starvation, because the bats have little extra fat reserve. Predation at the cave entrance by house cats, racoons, bobcats, and other animals has also caused significant mortality.
The U.S. Fish and Wildlife Service has established the Sequoyah/Oklahoma Bat Cave National Wildlife Refuge. In other areas, cave entrances have been fenced—to keep humans and domestic animals out of the caves but to allow bats access.
