Biological Exuberance: Animal Homosexuality and Natural Diversity

Sources

*asterisked references discuss homosexuality/transgender

Barkalow, F. S., Jr., and M. Shorten (1973) The World of the Gray Squirrel. Philadelphia and New York: J.B. Lippincott.

Ferron, J. (1981) “Comparative Ontogeny of Behavior in Four Species of Squirrels (Sciuridae).” Zeitschrift fur Tierpsychologie 55:193–216.

*———(1980) “Le comportement cohesif de l’Ecureuil roux (Tamiasciurus hudsonicus) [Cohesive Behavior of the Red Squirrel].” Biology of Behavior 5:118–38.

*Horwich, R. H. (1972) The Ontogeny of Social Behavior in the Gray Squirrel (Sciurus carolinensis). Berlin and Hamburg: Paul Parey.

Koprowski, J. L. (1994) “Sciurus carolinensis.” Mammalian Species 480:1–9.

———(1993) “Alternative Reproductive Tactics in Male Eastern Gray Squirrels: ‘Making the Best of a Bad Job.’” Behavioral Ecology 4:165–71.

———(1992a) “Do Estrous Female Gray Squirrels, Sciurus carolinensis, Advertise Their Receptivity?” Canadian Field-Naturalist 106:392–94.

———(1992b) “Removal of Copulatory Plugs by Female Tree Squirrels.” Journal of Mammalogy 73:572–76.

———(1991) “Mixed-species Mating Chases of Fox Squirrels, Sciurus niger, and Eastern Gray Squirrels, S. carolinensis.” Canadian Field-Naturalist 105:117–18.

*Layne, J. C. (1954) “The Biology of the Red Squirrel, Tamiasciurus hudsonicus loquax (Bangs), in Central New York.” Ecological Monographs 24:227– 67.

Moore, C. M. (1968) “Sympatric Species of Tree Squirrels Mix in Mating Chase.” Journal of Mammalogy 49:531–33.

Price, K., and S. Boutin (1993) “Territorial Bequeathal by Red Squirrel Mothers.” Behavioral Ecology 4:144–49.

*Reilly, R. E. (1972) “Pseudo-Copulatory Behavior in Eutamias minimus in an Enclosure.” American Midland Naturalist 88:232.

Smith, C. C. (1978) “Structure and Function of the Vocalizations of Tree Squirrels (Tamiasciurus).” Journal of Mammalogy 59:793–808.

*———(1968) “The Adaptive Nature of Social Organization in the Genus of Tree Squirrels Tamiasciurus.” Ecological Monographs 38:31–63.

Thompson, D. C. (1978) “The Social System of the Gray Squirrel.” Behavior 64:305–28.

———(1977) “Reproductive Behavior of the Gray Squirrel.” Canadian Journal of Zoology 55:1176–84.

———(1976) “Accidental Mortality and Cannibalization of a Nestling Gray Squirrel.” Canadian Field-Naturalist 90:52–53.

IDENTIFICATION: Woodchucklike rodents with gray, brown, reddish, or black fur. DISTRIBUTION: Olympic Peninsula, Washington; Alaska south to northwestern United States. HABITAT: Alpine slopes. STUDY AREAS: Olympic National Park, Washington; Glacier National Park, Montana; subspecies M.c. nivaria.

Social Organization

These two species of Marmots are highly social creatures that live in clusters of colonies; each colony is a series of underground burrows that is home to one male, one to three females, and their offspring. Males are generally not involved directly in parental care of their young. Occasionally an additional SATELLITE male is peripherally associated with an Olympic Marmot colony.

Description

Behavioral Expression: Olympic and Hoary Marmot females often mount other females and participate in other same-sex affectionate and sexual behaviors, especially when they are in heat. A homosexual encounter often begins with a “greeting” interaction in which the two females touch noses or mouths, or one female nuzzles her nose on the other’s cheek or mouth. She may also gently chew on the ear or neck of the other female, who then responds by raising her tail. The first female sometimes also sniffs or nuzzles the other’s genitals with her mouth. At this point she may mount the other female, gently biting her neck fur while she thrusts against her partner. The female being mounted arches her back and holds her tail to the side to facilitate the sexual interaction.

A female Olympic Marmot mounting another female

Frequency: Homosexual behavior is quite common in Marmots: in one study of Hoary Marmots, for example, three of five observed mounts by adults were between females.

Orientation: Many female Marmots that participate in same- sex mountings also mate with males. However, some nonbreeding females in Hoary Marmots (see below) probably also participate, which means that they may be involved only in homosexual interactions for those seasons that they do not breed.

Nonreproductive and Alternative Heterosexualities

Although many Marmots form monogamous heterosexual pair-bonds, in some populations the majority (two- thirds) of Hoary Marmots actually live in trios consisting of one male and two females. Occasionally a “quartet” of one male and three females live together as well. Some male Hoary Marmots also seek promiscuous matings with females outside their colony, a behavior that has been termed GALLIVANTING. A form of reproductive suppression occurs in this species as well: females usually procreate every other year, but 11 percent of the time, a female “skips” breeding for two consecutive years. This is especially common in trios, where the two females alternate their skipping patterns. Males sometimes still try to mount females that are not breeding, however. Sexual activity also occurs among juveniles, including mounting of adults.

Sources

*asterisked references discuss homosexuality/transgender

*Barash, D. P. (1989) Marmots: Social Behavior and Ecology. Stanford: Stanford University Press.

———(1981) “Mate Guarding and Gallivanting by Male Hoary Marmots (Marmota caligata).” Behavioral Ecology and Sociobiology 9:187–93.

*———(1974) “The Social Behavior of the Hoary Marmot (Marmota caligata) .” Animal Behavior 22:256–61.

*———(1973) “The Social Biology of the Olympic Marmot.” Animal Behavior Monographs 6:171–245.

Holmes, W. G. (1984) “The Ecological Basis of Monogamy in Alaskan Hoary Marmots.” In J. O. Murie and G. R. Michener, eds., The Biology of Ground-Dwelling Squirrels: Annual Cycles, Behavioral Ecology, and Sociality, pp. 250–74. Lincoln: University of Nebraska Press.

Wasser, S. K., and D. P. Barash (1983) “Reproductive Suppression Among Female Mammals: Implications for