endangered. HABITAT: Upland forests. STUDY AREA: Jersey Wildlife Preservation Trust, England.
VAMPIRE BAT
IDENTIFICATION: A small bat with grayish brown fur and pointed ears. DISTRIBUTION: Northern Mexico through central Chile, Argentina, Uruguay; Trinidad. HABITAT: Forests, open areas; roosts in caves, tree hollows. STUDY AREAS: Hacienda La Pacifica and Parque Nacional de Santa Rosa, Costa Rica; University of the West Indies, Trinidad.
Social Organization
Gray-headed Flying Foxes live in groups known as CAMPS, which may contain many thousands of individuals. These camps are segregated by sex for most of the year: males and females roost in separate trees—or in separate locations within the same tree—except during the breeding season (generally March-April). Some individuals become nomadic, solitary, or much less gregarious following the breeding season. Livingstone’s Fruit Bats appear to have a polygamous mating system, in which males mate with multiple female partners but do not participate in raising their offspring. Vampire Bat colonies may contain up to 2,000 individuals, although most have 20–100. The female group is the primary social unit, consisting of 8–12 females (many of whom are related to each other) and their young. Males sometimes form “bachelor” groups of up to 8 individuals, or they may roost in the same tree with female groups.
Description
Male Vampire Bats also participate in sexual grooming and licking of one another. Two males hang belly to belly, each with an erect penis. One male then works his tongue over the entire body of the other male, paying particular attention to licking the other male’s genitals. Sometimes one male will masturbate himself while licking his partner, using his free foot to rub his own penis. Although overt sexual behavior has not been observed among female Vampire Bats, females do form long-lasting bonds with one another. Companions share the same roost, groom one another, huddle together, and go foraging with each other. Another important aspect of these female companionships is blood-sharing: one female feeds the other by “donating” or regurgitating blood for her to consume (males also occasionally engage in reciprocal blood-sharing). Associations like these can last for five to ten years or more, and some females bond with several different female companions simultaneously.
Nonreproductive and Alternative Heterosexualities
Heterosexuality in all three of these species of Bats is characterized by a variety of nonreproductive sexual behaviors. Gray-headed Flying Foxes copulate throughout the year, including outside the breeding season when females cannot get pregnant, and mating also takes place during pregnancy. In addition, males have a distinct annual hormonal cycle that affects sperm production, with the result that many of their matings are nonprocreative. Male Livingstone’s Fruit Bats sometimes participate in heterosexual mounting without an erection or penetration, and females may REVERSE mount males as well. A prominent feature of Gray-headed Flying Fox sexual behavior is oral sex, in which the male deeply tongues the female’s genitalia for long periods. Both male and female Livingstone’s Fruit Bats also lick the genitals of their partners during heterosexual interactions. In Vampire Bats, masturbation occurs among younger males, while male Livingstone’s Fruit Bats have been observed licking their own penises to erection. Female Vampire Bats sometimes mate with several different males in succession. In this species, a vaginal plug forms in the female’s reproductive tract following copulation, which may prevent insemination from subsequent matings. When not in heat females frequently refuse to mate with males altogether, especially aggressive ones. Heterosexual relations in Livingstone’s Fruit Bats are also less than amicable: females sometimes cuff males or otherwise refuse their advances, and partners may threaten, wrestle, cuff, and bite each other during actual courtship and mating. Vampire Bats have developed an alternative form of parenting behavior in their female groups known as FOOD SHARING: females sometimes help each other feed infants by regurgitating blood for young that are not their own.
Other Species
Male Serotine Bats (
*Barclay, R. M. R., and D. W. Thomas (1979) “Copulation Call of