203.

Tricolored Bat

Perimyotis subflavus

French: Blondin de Cuvier / German: Dreifarb-Zwergfledermaus / Spanish: Pipistrela tricolor

Other common names: Eastern Pipistrelle

Taxonomy. Vespertilio subflavus F. Cuvier, 1832,

“De Géorgia [= Georgia, USA].”

Previously paced in Pipistrellus, subgenus Perimyotis, but morphological and molecular data support raising Perimyotis to genus level. Races based on morphological differences. Four subspecies recognized.

Subspecies and Distribution.

P.s.subflavusF.Cuvier,1832—SECanada(SQuebec,NewBrunswick,andNovaScotia)andEUSA(MinnesotaandNewEnglandStoTexasandSGeorgia;isolatedrecordinColorado).

P.s.clarusR.H.Baker,1954—NCoahuilainNEMexicoandadjacentpartsofTexas(USA).

P.s.flonidanusW.H.Davis,1957—SEGeorgiaandthroughoutFloridaPeninsula.

P.s. veraecrucis Ward, 1891 — NE Mexico S to Guatemala and NE Honduras.

Descriptive notes. Head-body c.43-48 mm, tail 34-41 mm, ear 12-4-14-1 mm, hindfoot 7-3-9-9 mm, forearm 31-4-34-1 mm; weight 5-10 g. Females larger than males. Fur medium to long (dorsal fur 5-8 mm); dorsal hairs tricolored, being dark at base, lighter and yellowish brown in middle, and dark attip; pelage color varies geographically, from pale yellow orange to dark reddish brown dorsally, and from pale yellow orange to dark mahogany ventrally; long guard hairs are completely orange orsilvery. Ears short, tapering to narrowly rounded tip, extending forward halfway from eye to nostril; tragus long, straight, and bluntly rounded. Muzzle and facial areas contain sebaceous glands with hair follicles. Membranes are blackish, contrasting with reddish forearms; membrane between second and third metacarpal is mummy brown. Plagiopatagium is broadly attached to foot at level of base of toes; anterior one-third of interfemoral membrane is furred; calcar is unkeeled. Baculum is Y-shaped with prongs at proximal position. Skull is small (greatest skull length 12-4-13-1 mm); rostrum gently sloped with no concavities on dorsal surface. Upper incisors have wider tips than bases; there are eight teeth in upper quadrant; upper incisors unicuspid. Dental formulais12/3,C1/1,P 2/2, M 3/3 (x2) = 34. Chromosomal complement has 2n = 30 and FN = 56, with ten large to medium-sized metacentric and submetacentric pairs of autosomes, four small submetacentric, a medium-sized submetacentric X-chromosome, and a small acrocentric Y-chromosome.

Habitat. Open woods, grassland, and semideciduous forests.

Food and Feeding. Insectivorous, foraging in forests, agricultural fields, forest edges, and open habitats, mostly near water bodies. Diet includes a large variety of insects, particularly Lepidoptera, Coleoptera, and Orthoptera, all caught in flight. During feeding maneuvers, tail and wing membranes are used to capture and restrain prey. Tail membrane forms a pouch-like compartment, and the bat must bend its head forward in order to grasp the insect with its teeth and take it into its mouth.

Breeding. Copulation occurs August-October, the only period when males and females are together in roosts. During breeding season, females mate with several males; after copulation, females store sperm over hibernation until they ovulate in spring. Insemination occurs in spring. Up to seven ova may be fertilized, but only two will implant, resulting in twins. Gestation lasts c.45 days from time of implantation to parturition. Births occur from end of Mayto earlyJuly. Sexual maturity is at c.1 year of age.

Activity patterns. Nocturnal, with emergence just after sunset. Summer roosts include rock crevices, caves, human buildings, and tree foliage; in winter, caves, mines, and deep crevices serve as hibernacula. Call means are: minimum frequency 43 kHz, maximum frequency 71-5 kHz, peak frequency 46 kHz, bandwidth 28-5 kHz, and call duration 5-6-8 milliseconds.

Movements, Home range and Social organization. Movements poorly understood. Some evidence suggests the species may undertake annual latitudinal migrations, similar to other North American long-distance migratory bats. Longest migration distance recorded was a female banded in April in Massachusetts, and recovered at least 52 km away in its hibernaculum. This species is obligate hibernator, even in warmer climates with available food; it generally hibernates alone, but groups of 2-3 occur. During summer, females roost in maternity colonies (average 15 individuals); males roost alone.

Status and Conservation. Classified as Vulnerable on The [UCN Red List, because of the advance of White-nose Syndrome (caused by an invasive European fungus, Pseudogymnoascus destructans) over much of its range; population could decrease by 45% over next 15 years. Despite expected large population, occurrence in protected areas, and tolerance to some degree of habitat modification, the impact of this disease has been extremely severe.

Bibliography. Adams et al. (2018), Fraser et al. (2012), Fujita & Kunz (1984), Gaona & Medellin (2014), Hoofer & Van Den Bussche (2003), Menu (1984), Roehrs et al. (2010), Simmons (2005), Solari (2018k), Whitaker & Hamilton (1998), Wilson & Ruff (1999).