245.

Rafinesque’s Big-eared Bat

Corynorhinus rafinesquii

French: Oreillard de Rafinesque / German: Rafinesque-Langohr / Spanish: Orejudo de Rafinesque

Taxonomy. Plecotus rafinesquii Lesson, 1827,

“les Etats-Unis.” Restricted by C. O. Handley, Jr. in 1959 to “Mount Carmel, Wabash County, Ill[inois].”

Originally described as Vespertilio megalotis by C. S. Rafinesque in 1818, but this name is preoccupied, and the taxon was renamed in Plecotus . However, morphological and karyological analyses indicated its distinctness from Old World Plecotus, supporting its inclusion in subgenus Corynorhinus . Molecular and morphological analyses support the elevation of Corynorhinus to genus level. Separation into races is not supported by molecular data, and internal taxonomy needs to be reviewed. Two subspecies recognized.

Subspecies and Distribution. C.r.rafinesquiiLesson,1827—E&SIllinois,W&SIndiana,SOhio,SEMissouri,Ken-tucky,Tennessee,WNorthCarolina,andEArkansas(EUSA).

C. r. macrotis Le Conte, 1831 — E North Carolina, South Carolina, Georgia, Florida, Alabama, Mississippi, Louisiana, E Texas, and extreme SW Arkansas.

Descriptive notes. Head—body ¢. 38-56 mm, tail 42-54 mm, ear 27-37 mm, hindfoot 8-13 mm, forearm 38-8-43- 5 mm; weight 7-9-13- 6 g. Females tend to weigh more than males. Fur is long; dorsal hairs bicolored, with blackish bases and smoky-graytips; ventral hairs bicolored, with strongly contrasting blackish bases and white or pale tips. Ears large, joined basally across forehead. Muzzle has dorso-lateral glandular masses, rising above muzzle as prominent lumps; nostrils elongated posteriorly; accessory basal lobe of auricle is absent. Ears and face pinkish brown, membranes dark brown. Plagiopatagium broadly attached to foot at level of base of toes; calcar not keeled; two long toe hairs extend beyond tips of claws. Skull is moderate in size (greatest skull length 13-2-15- 1 mm), slender, and highly arched; rostrum reduced; lacrimal region smoothly rounded; supraorbital region not ridged; temporal ridges normally coalesced to form sagittal crest. Median post-palatal process triangular, with broad base; I? has prominent secondary cusp; anterointernal cusp is usually present on cingulum of Pt, Dental formula for all species of Corynarkinusis12/3, C1/1,P 2/3. M 3/3 (x2) = 36. Chromosomal complement has 2n = 32 and FN = 50, with ten pairs of metacentric and five pairs of acrocentric autosomes, and acrocentric X- and Y-chromosomes.

Habitat. Mostly in forested areas and riparian associations, from sea level up to 800 m.

Food and Feeding. Insectivorous, foraging in forested areas, over open fields, and near watercourses. Diet comprises mostly small lepidopterans, with some records of dipterans and coleopterans. Prey is mainly captured in flight by aerial-hawking, butis sometimes gleaned from cave walls or leaf surfaces.

Breeding. Copulation takes place in autumn and winter. Females give birth to single young in late May and earlyJune. Parturition occurs a few days earlier in south than in north of range. Young are closely associated with adult females for about three weeks after parturition. Females form maternal colonies without males.

Activity patterns. Nocturnal, with emergence from roost later at night than many other bat species;it starts foraging after sunset and continues until around midnight;it begins again c.5 hours later, and returns to its roosting site before sunrise. Its natural roosts are caves, hollow trees, and crevices behind bark, and under dry leaves. Frequently observed in buildings, such as abandoned mines and bridges. Call parameters (mean) are: minimum frequency 22-2 kHz, maximum frequency 45-5 kHz, peak frequency 31-4 kHz, bandwidth 21-6 kHz, and call duration 3-2 milliseconds.

Movements, Home range and Social organization. Apparently, the species has a small home range (c.0-9- 1-6 km?) and does not migrate. Within a roosting area, it moves about frequently both in summer and winter. It hibernates during winter and may exhibit torpor behavior during summer. Colonies number ¢.2-100 individuals, and winter roosts can harbor up to ¢.700; solitary bats are also found. The species frequently roosts with other bat species, such as the Tricolored Bat ( Perimyotis subflavus), the South-eastern Myotis ( Myotis austroriparius), and Townsend's Big-eared Bat ( Corynorhinus townsendiz), but tends to form conspecific clusters or to roost some distance away from the other species.

Status and Conservation. Classified as Least Concern on The IUCN Red List. In general, populations appear stable over its wide range, although local declines have been reported.

Bibliography. Arroyo-Cabrales & Alvarez-Castafeda (2017c), Barbour & Davis (1969), Bogdanowicz et al. (1998), Dood et al. (2015), Hall (1981), Handley (1959), Jones, C. (1977), Lesson (1827), Menzel, Menzel, Ford et al. (2001), Piaggio & Perkins (2005), Rafinesque (1818), Simmons (2005), Wilson & Ruff (1999).