Corynorhinus rafinesquii
Rafinesque's big-eared bat

The range of Corynorhinus rafinesquii extends from the southern parts of Indiana, Illinois, and Ohio to the southeastern United States. They are found from the eastern part of Texas to North Carolina. They are most common in the Coastal Plain. (Handley, 1955)

Rafinesque’s big-eared bats roost in cave entrances, hollow trees, crevices behind bark, and dry leaves in the forest. They also live in abandoned buildings and under bridges and prefer to roost in partially lighted areas. (Barbour and Davis, 1969; Handley, 1955)

Corynorhinus rafinesquii is a medium size bat with rabbit-like ears. Their ears are about an inch and a half long. They are able to curl the ears backwards over the shoulders. Young bats have gray fur, but they acquire their adult fur three months after birth. The adult color of their fur is grayish brown on top and whitish beneath. Each hair in the stomach has a dark brown base and white tips. The hairs in the long toe extend past the claws. Rafinesque’s big-eared bats weigh between 7-13 g. Adult females are heavier than the adult males. The average weight for females is 9.1 grams and the average weight for males is 8.1 grams. Adult bats are only four inches long but they have a wingspan of eleven inches. Rafinesque’s big-eared bats have a prominent nose. Two large facial glands protrude on the side of its snout. (Barbour and Davis, 1969; Bat Conservation International, 1999; Jones, 1977)

Rafinesque’s big-eared bats mate in the fall and the females give birth in the summer. The exact gestation period is unknown. In maternity colonies, the females give birth to a single pup in late May and early June. The maternity colonies are usually located in caves or abandoned buildings. The “nursery colonies” are comprised of between 30 to 200 females. Pregnant females segregate from males and non-reproductive females during the spring and summer to rear their young. (Handley, 1955; Jones, 1977; Wimsatt, 1970)

These bats are born naked but they grow gray fur days after birth. The pups are able to fly in three weeks after birth and reach adult size in about a month. Also, the pups molt to their adult fur three months after birth. Females nurse the young in the nursery colony until they reach independence. (Handley, 1955)

The average lifespan for the rafinesque's big-eared bat is ten years in the wild for males and females. (Jones, 1977)

Corynorhinus rafinesquii roosts in caves, mines, and hollow trees. They also roost in man-made structures such as abandoned buildings, wells, and bridges. Rafinesque’s big-eared bats are capable of immediate flight when disturbed. However, they are susceptible to predators when they are hibernating because it takes them several minutes to wake up. They hibernate during the winter. During hibernation, the males and the females sleep in the same place, unlike during the summer when they roost in separate areas. When these bats hibernate, they coil their ears in front of their face and fold their wings. During the summer, they are capable of immediate flight at night. They can fly swiftly but they can also hover. (Barbour and Davis, 1969; Jones, 1977; Wimsatt, 1970)

Rafinesque’s big-eared bats, like most other bats, feed at night. They use echolocation to find their food. Their diet includes mosquitoes, beetles, and flies. However, moths make up 90% of the bat’s diet. (Defenders of Wildlife, 1999; Jones, 1977)

Some of their predators are snakes, raccoons, opossums, and cats. (Jones, 1977)

Rafinesque's big-eared bats help control the insect population.

Rafinesque's big-eared bats feed on insects that can be harmful to agriculture.

There are no adverse effects of Rafinesque's big-eared bats on humans.

Rafinesque’s big-eared bats have been threatened since 1977 because of loss of roosting areas.

Temperate North American bats are now threatened by a fungal disease called “white-nose syndrome.” This disease has devastated eastern North American bat populations at hibernation sites since 2007. The fungus, Geomyces destructans, grows best in cold, humid conditions that are typical of many bat hibernacula. The fungus grows on, and in some cases invades, the bodies of hibernating bats and seems to result in disturbance from hibernation, causing a debilitating loss of important metabolic resources and mass deaths. Mortality rates at some hibernation sites have been as high as 90%. While there are currently no reports of Corynorhinus rafinesquii mortalities as a result of white-nose syndrome, the disease continues to expand its range in North America. (Cryan, 2010; National Park Service, Wildlife Health Center, 2010)

Rafinesque’s big-eared bats are one of the least known bats in the southeastern United States. Corynorhinus rafinesquii was previously known as Plecotus rafinesquii. Southeastern-big eared bat, eastern big-eared bat, eastern lump-nosed bat, and eastern long-eared bat are other common names for Rafinesque’s big-eared bat. (Jones, 1977)