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.

Biogeographic Regions: nearctic (Native )

endemic to a single nation

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (200,000-2,500,000 square km (about 80,000-1,000,000 square miles)) The range extends from southern Virginia, West Virginia, Ohio (Handley 1991), Indiana, and Illinois south to Florida (primarily the panhandle and northern and central portions of the peninsula) and the Gulf of Mexico; west to Louisiana, Arkansas (known primarily from the Gulf Coastal Plain), eastern Oklahoma, and the eastern edge of Texas (Schmidly 2004) (Whitaker and Hamilton 1998; Lynch and Jones, in Wilson and Ruff 1999). Elevational range in the Great Smoky Mountains National Park extends to at least 2,400 feet (D. Linzey and C. Brecht).

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.

Range mass: 7 to 13 g.

Average wingspan: 28 mm.

Other Physical Features: endothermic ; heterothermic ; bilateral symmetry

Sexual Dimorphism: female larger

Length: 11 cm

Weight: 12 grams

Differs from C. townsendii and C. mexicanus by having the ventral hairs black with white or whitish tips (rather than gray or brownish with brownish or buff tips); also, except in subspecies ingens, the first upper incisor in townsendii usually does not have a secondary cusp (Jones 1977).

• Terrestrial

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.

Habitat Regions: temperate ; terrestrial

Terrestrial Biomes: forest

Other Habitat Features: caves

Comments: This is a bat of forested regions. Hibernation in the north and in mountainous regions most often occurs in caves or similar sites; small caves are selected, and the bats stay near the entrance (often within 30 meters) and are thought to move about in winter (Handley 1959, Barbour and Davis 1969). In Kentucky, shallow caves or rock shelters in sandstone formations of the Cumberland Plateau often are used (MacGregor 1992). Winter habitat in the south is poorly known, but usually this species is not found in caves during winter. In the Coastal Plain they are suspected to use hollow trees for cold weather and possibly winter roosts (Clark 1992). In the southern portions of the range these bats often roost in buildings year round.

Summer roosts often are in hollow trees, occasionally under loose bark, or in abandoned buildings in or near wooded areas. Nursery colonies are rare in caves, but are known to occur in Kentucky and Tennessee (Barbour and Davis 1969). A large nursery colony (87 adults in June of 1985) roosts in abandoned copper mines in Great Smoky Mountains National Park (Currie 1992).

In Louisiana, Gooding and Langford (2004) found that roost trees were hollow Nyssa aquatica with triangular-shaped basal openings, and all were located within a 5-hectare tupelo stand. In Mississippi, Trousdale and Beckett (2005) found that tree roosts were in hollow Nyssa spp. and Magnolia grandiflora. Most of the trees were still alive, relatively large, and were adjacent to streams or other bodies of water. Tree roosts were apparently rare within the study area, and C. rafinesquii showed roost fidelity to particular areas of forest. Six tree roosts were used by multiple individuals and several trees were reused within tracking sessions and among years.

In Louisiana, Lance et al. (2001) demonstrated that bridges, especially girder bridges, are important day-roost sites. Tagged bats in this study roosted under bridges 50% of the time and in black gum trees (Nyssa aquatica) 50% of the time. In Mississippi, small groups of females (mean of 5.6 adult females) used concrete bridges as maternity roosts; the bridges were much less used in fall and winter (Trousdale and Beckett 2004). It has been suggested that the species began using man-made structures in the coastal plain region only after large old hollow trees became scarce (Currie 1992, Clark 1992).

In Arkansas these bats are found in cisterns and wells rather than caves (Harvey 1992b). In the mountains of South Carolina they roost in rock houses, abandoned gold mines, and hollow trees (Strayer 1992b). In the coastal plain of North Carolina, they move into old buildings in the summer. They are known to use hollow trees as temporary night roosts between feeding bouts in the summer (Clark 1992). In central Florida, a maternity roost was in an abandoned trailer that had been placed on a site in the early 1980s; it had been occupied for several years by the mid-1990s (Finn 1996).

Dilapidated buildings are inhabited more commonly than are intact occupied structures, and Clark (1987) and Strayer (1992) reported that these bats roost in the darkest parts of such buildings. Others have reported that these bats choose more open and lighted daytime roosts than other kinds of bats (Handley 1959, Barbour and Davis 1969, Harvey 1992). Clark (1987) agreed that in caves and mines this species prefers areas receiving some natural light.

The foraging habitat is primarily mature forest in both upland and lowland areas. In North Carolina and Virginia, foraging habitat for subspecies Macrotis is mature hardwood floodplain forest; sites along permanent water bodies, especially rivers, are preferred (Clark 1987). In the Upper Coastal Plain of South Carolina, where large contiguous tracts of mature bottomland hardwoods were common, most foraging activity of males nevertheless occurred in young pine stands; only 9% of foraging areas were in bottomland hardwoods (Menzel et al. 2001).

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

This species is basically nonmigratory and moves only short distances between summer and winter roosting sites.

In Kentucky, based on radio-tagged individuals that used a cave as a hibernaculum as well as a maternity colony, size of foraging areas ranged from 61.6225.3 ha, and distance of foraging areas from the roost varied from 0.121.22 km; no bat was detected >2.5 km from the roost of capture (Hurst and Lacki 1999).

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.

Animal Foods: insects

Primary Diet: carnivore (Insectivore )

Comments: Probably depends upon flying insects, particularly moths. May hover and pluck insects from foliage (Whitaker 1980). Foraging habitats are unknown (Handley 1991).

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

Some of their predators are snakes, raccoons, opossums, and cats.

Known Predators:

• raccoons (Procyon lotor)
• Virginia opossums (Didelphis virginiana)
• domestic cats (Felis silvestris)
• snakes (Serpentes)

Anti-predator Adaptations: cryptic

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 21 - 300

Comments: The number of occurences is certainly greater than 100, but the number of known extant summer and winter roosting sites with large numbers of bats (> 100) is only 6 to 8 in any one year, and these sites are clustered in Kentucky and North Carolina. As of 2005, the species had been recorded from 18 counties in Tennessee (Tennessee Bat Working Group). MacGregor (1992) commented that although Kentucky has many records of the species, it has only 15 colonies with 30 or more bats. The fact that this species is often found singly inflates the number of occurences, and it is unclear whether very small maternity colonies are productive.

2500 - 100,000 individuals

Comments: Population size is not known to exceed 10,000 mature individuals, but data are lacking for many areas.

This bat never has been considered abundant. In general, it roosts in small numbers at scattered locations (e.g., in Alabama, the largest known colony includes only a few individuals; T. L. Best). Population is thought to be 1,000-2,000 in each of Kentucky and South Carolina.

This is one of the most common bats in the Great Smoky Mountains National Park; hibernation roosts include up to several hundred individuals (e.g., in 1993, two roosts included 454 and 699 bats) (D. Linzey and C. Brecht); Harvey (1991) reported a hibernating colony of 570 individuals as well as smaller maternity roosts.

In a cave in Kentucky, counts of hibernating C. rafinesquii ranged from 14-49, with summer colony size reaching a maximum of 118 bats (Hurst and Lacki 1999). In southern Mississippi, the number of bats present under occupied bridges ranged from 1 to 25 per bridge (Trousdale and Beckett 2004).

In Florida, this bat is uncommon in the northern part of the state and rare in the south (Florida Bat Center, www.floridabats.org). In Georgia, it is widespread but rare (Georgia Wildlife Web).

In much of the range thorough searches have not been completed and abundance is poorly known.

Roosts singly, in small clusters, or in larger groups of up to 100 or more (Handley 1991). In most colonies, females outnumber males. Males are mainly solitary during the nursing season. When disturbed, awakens quickly and takes flight almost immediately (Layne 1978).

Comments: Big-eared bats emerge from roosts usually well after dark, returns to roosting site prior to dawn (do not feed in twilight).

This bat hibernates in the more northerly part of the range (e.g., Kentucky and South Carolina); often active in winter in the south (e.g., Louisiana, eastern Texas; Schmidly 2004). The duration of hibernation in Alabama is unknown (T. L. Best).

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

Average lifespan

Status: wild: 10 years.

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.

Range number of offspring: 1 to 1.

Range weaning age: 21 (low) days.

Average weaning age: 21 days.

Range time to independence: 3 (low) weeks.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); 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.

Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)

Mates in autumn and winter. Gestation lasts possibly 2.5-3 months. Litter of one is born in late May-early June in the north, apparently mostly in May in Florida (e.g., see Finn 1996). Young can fly at about 3 weeks. Longevity is at least 8-10 years. Maternity colonies range in size from several to about 100 individuals; larger in the north than in the far south.

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.

US Federal List: threatened

CITES: no special status

IUCN Red List of Threatened Species: least concern

United States

Rounded National Status Rank: N3 - Vulnerable

Rounded Global Status Rank: G3 - Vulnerable

Reasons: Widespread in the southeastern U.S.; large number of occurrences but many consist of very small groups or single individuals; some evidence suggests population declines in several states, though several protected colonies have increased in number of individuals; sensitive to nondestructive intrusion.

Other Considerations: No state ranks this species more secure than S3.

Global Short Term Trend: Relatively stable to decline of 30%

Comments: No range-wide statistics on trends are available, but four states (Georgia, West Virginia, South Carolina, and Tennessee) reported documented population declines, and populations in Indiana and Ohio probably have been extirpated. Four other states (Alabama, Arkansas, Illinois, and North Carolina) reported suspected declines. In summary, the species is known or suspected to be declining in more than half (10 out of 18) of the states within its range. In most other states, data are unavailable to determine trends. MacGregor (1992) noted that colonies of this bat in Kentucky seem to remain stable in size.

Degree of Threat: B : Moderately threatened throughout its range, communities provide natural resources that when exploited alter the composition and structure of the community over the long-term, but are apparently recoverable

Comments: Much historically occupied habitat was lost with the clearing of swampland forests. Present threats include: forest destruction (significant in parts of coastal plain); hollow tree removal during certain forest management practices (widespread; noted in Mississippi as important); decreasing availability of abandoned buildings through razing and vandalism (serious threat in coastal plain); insecticide applications, at least in past; vandalism of caves and mines, and closing or blasting mines shut (England et al. 1992, Clark 1992). There is considerable potential for loss and degradation of roosting and foraging habitats by commerical logging practices in preferred habitat (Schmidly 2004).

This species is very intolerant of disturbance (natural or human) and may abandon roost sites or hibernation sites if subjected to disturbance. Disturbance in winter may arouse bats and cause them to use up fat needed to survive the winter (Harvey 1992b). Tendency to roost in cave entrances makes this bat especially vulnerable to disturbance. One roost site was abandoned after the surrounding area was logged (Clark 1992).

Management Requirements: Primary management needs include elimination of disturbance of roosts and protection of roosting and foraging habitat through compatible forestry practices.

Biological Research Needs: More accurate information is needed on general biology, foraging habitat, foraging behavior, and the importance of mature forests, hollow trees for roosts, and small maternity colonies.

Global Protection: Few to several (1-12) occurrences appropriately protected and managed

Comments: Several occurrences are known from state or national parks, including the largest known hibernating colony and some large (>100 individuals) maternity colonies in the Great Smoky Mountains National Park. Two large hibernating colonies in the Great Smoky Mountain National Park are partially protected, one with a gate and the other with fencing.

Additional protected occurrences include (but are not limited to) the following. One protected colony occurs in Carter Cave, Kentucky. A colony also occurs in Natural Bridge State Park in Kentucky. South Carolina protects two bat roosting areas that fall within state parks by restricting access to bat areas (Strayer 1992). Sites on USFS property are required under NEPA to be considered when evaluating effects of management practices. One large maternity colony is within Mammoth Caves National Park. Arkansas has gated several caves with Myotis sodalis colonies, and these may also be potential roost sites for Rafinesque's long-eared bats (Harvey 1992b). Two maternity colonies in old buildings in Illinois have been protected, and the buildings repaired to extend their useful life (Gardner 1992).

Needs: Protect all colony sites with more than 10 bats present. Foraging habitat may be critical to species survival and should therefore be protected (protect mature floodplain and swamp forests; maintain large hollow tree component of such forests). Abandoned-building roost sites should be protected or, if need be, replaced with a potential alternate roost area on the site (Fin 1996).

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

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

Positive Impacts: controls pest population

Comments: This bat was referred to as Corynorhinus macrotis in older literature, and Corynorhinus townsendii was known as C. rafinesquii. It was placed in the genus Plecotus by Handley (1959). Frost and Timm (1992) evaluated morphological and karyological characters from a phylogenetic perspective; they re-elevated the subgenus Corynorhinus to full genus status--the North America species Plecotus mexicanus, P. rafinesquii, and P. townsendii were moved from the genus Plecotus and once again placed in the genus Corynorhinus, leaving the Old World species Plecotus auritus, P. austriacus, and P. tenerrifae as the only members of the genus Plecotus. A morphological phylogenetic analysis by Tumlison and Douglas (1992) also concluded that mexicanus, rafinesquii, and townsendii should be placed in the genus Corynorhinus. Bogdanowicz et al. (1998) examined morphological and chromosomal variation and found that Corynorhinus is strongly supported as a distinct genus, with Plecotus limited to Palearctic species. The mammal lists by Baker et al. (2003) and Simmons (in Wilson and Reeder 2005) also accepted Corynorhinus as the appropriate genus for New World big-eared bats.