By Eduardo Reyes
Geographic Range
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)
Habitat
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)
These animals are found in the following types of habitat:
temperate
; terrestrial
.
Terrestrial Biomes:
forest
.
Other:
caves.
Physical Description
(0.25 to 0.46 oz; avg. 0.35 oz)
(1.1 in)
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)
Some key physical features:
endothermic
; heterothermic
; bilateral symmetry
.
Sexual dimorphism:
female larger.
Reproduction
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)
Key reproductive features:
iteroparous
; seasonal breeding
; gonochoric/gonochoristic/dioecious (sexes separate); sexual
; viviparous
; sperm-storing
.
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)
Parental investment:
altricial
; pre-fertilization (provisioning, protecting: female); pre-hatching/birth (provisioning: female, protecting: female); pre-weaning/fledging (provisioning: female, protecting: female).
Lifespan/Longevity
The average lifespan for the rafinesque's big-eared bat is ten years in the wild for males and females. (Jones, 1977)
Behavior
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)
Food Habits
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)
Primary Diet:
carnivore
(insectivore
).
Animal Foods:
insects.
Predation
- raccoons (Procyon lotor)
- Virginia opossums (Didelphis virginiana)
- domestic cats (Felis silvestris)
- snakes (Serpentes)
Some of their predators are snakes, raccoons, opossums, and cats. (Jones, 1977)
Anti-predator adaptations::
cryptic
.
Ecosystem Roles
Rafinesque's big-eared bats help control the insect population.
Economic Importance for Humans: Negative
There are no adverse effects of Rafinesque's big-eared bats on humans.
Economic Importance for Humans: Positive
Rafinesque's big-eared bats feed on insects that can be harmful to agriculture.
Ways that people benefit from these animals:
controls pest population.
Conservation Status
IUCN Red List: [link]:
Vulnerable.
US Federal List: [link]:
Threatened
.
CITES: [link]:
No special status.
Rafinesque’s big-eared bats have been threatened since 1977 because of loss of roosting areas.
Other Comments
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)
Contributors
Eduardo Reyes (author), University of Michigan.
Bret Weinstein (editor), University of Michigan.

