Endangered Species
Midwest Region



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Ozark Big-eared Bat (Plecotus townsendii ingens)

Fact Sheet


photo of Ozark big-eared bat


Also known as the lump-nosed bat, the western big-eared bat, and the long-eared bat, the Ozark big-eared bat is born with its long ears draped over its eye for the first few days.


Status: Endangered


Habitat: This bat prefers caves in limestone karst formations, in regions dominated by mature hardwood forests of hickory, beech, maple and hemlock trees. Maternity caves, where females bear and raise their young are closer to food sources than are hibernation caves, which are better protected from cold and wind.


Behavior: Big-eared bats are nocturnal and navigate by echolocation - they make high-pitched cries which return as echoes when the sounds bounce off solid objects. They also use echolocation to find food, which usually consists of moths and other insects.

Ozark big-eared bats mate in the fall after ritual vocalizations and head-nuzzling. Females store the sperm through the winter and become pregnant after emerging from hibernation in the spring. They give birth two to three months later after migrating to a maternity colony.


Why It's Endangered: Ozark big-eared bats have suffered greatly from human disturbance of caves due to exploration and commercialization. Bats enter hibernation with only enough fat reserves to last until spring. When stirred up by cave explorers or other people, a bat may burn up 10 to 30 days of its fat supply. These bats may starve to death before the warm spring weather arrives and they can begin feeding again. The bat is now limited to a few isolated populations in Arkansas and Oklahoma.


Fact Sheet prepared September 22, 1997




Last updated: July 19, 2016