Biological Exuberance: Animal Homosexuality and Natural Diversity

years, some heterosexual courtship activity in both Muskoxen and Mountain Goats may be directed by males toward nonprocreating individuals such as yearlings and calves. In addition, male Mountain Goats sometimes court and mount females outside the breeding season or even court females in the act of giving birth. Females in this species have been observed mounting adult males and courting, mounting, or being mounted by their own yearlings or kids. Relations between the sexes are often marked by strife. Females of both species sometimes reject the courtship and mounting attempts of males. Male Musk-oxen may become violent during their courtship kicks of females (the impact of the blow against a female’s spine or pelvis can be considerable). As many as two-thirds of Musk-ox mounts may not culminate in ejaculation, because the male is anatomically unsuited to remaining mounted on the female (he is considerably heavier than her and unable to clasp with his forelegs during a mount). Among Mountain Goats, females are often notably aggressive toward males, attacking and sometimes viciously wounding them with stabs from their sharp horns. In addition, violence toward calves has been observed among Musk-oxen: females sometimes flip calves other than their own into the air with their horns, while males have been known to gore calves.

Other Species

In the distantly related Himalayan Tahr (Hemitragus jemlahicus), intersexuality sometimes occurs: one individual, for example, had testes and the general appearance of a male combined with a vulva, enlarged clitoris, and a female chromosome pattern.

Sources

*asterisked references discuss homosexualityltransgender

*Benirschke, K. (1981) “Hermaphrodites, Freemartins, Mosaics, and Chimaeras in Animals.” In C. R. Austin and R. G. Edwards, eds., Mechanisms of Sex Differentiation in Animals and Man, pp. 421–63. London: Academic Press.

Chadwick, D. H. (1983) A Beast the Color of Winter: The Mountain Goat Observed. San Francisco: Sierra Club Books.

*———(1977) “The Influence of Mountain Goat Social Relationships on Population Size and Distribution.” In W. Samuel and W. G. Macgregor, eds., Proceedings of the First International Mountain Goat Symposium, pp. 74–91. Victoria, B. C.: Fish and Wildlife Branch.

*Geist, V. (1964) “On the Rutting Behavior of the Mountain Goat.” Journal of Mammalogy 45:551–68.

Gray, D. R. (1979) “Movements and Behavior of Tagged Muskoxen (Ovibos moschatus) on Bathurst Island, N.W.T.” Musk-ox 25:29–46.

———(1973) “Social Organization and Behavior of Muxkoxen (Ovibos moschatus) on Bathurst Island, N.W.T.” Ph.D. thesis, University of Alberta.

*Hutchins, M. (1984) “The Mother-Offspring Relationship in Mountain Goats (Oreamnos americanus).” Ph.D. thesis, University of Washington.

Jingfors, K. (1984) “Observations of Cow-Calf Behavior in Free-Ranging Muskoxen.” In D. R. Klein, R. G. White, and S. Keller, eds., Proceedings of the First International Muskox Symposium, pp. 105–9. Biological Papers of the University of Alaska Special Report no. 4. Fairbanks: University of Alaska.

Lent, P. C. (1988) “Ovibos moschatus.” Mammalian Species 302:1–9.

*Reinhardt, V. (1985) “Courtship Behavior Among Musk-ox Males Kept in Confinement.” Zoo Biology 4:295–300.

*Smith, T. E. (1976) “Reproductive Behavior and Related Social Organization of the Muskox on Nunivak Island.” Master’s thesis, University of Alaska.

*Tener, J. S. (1965) Muskoxen in Canada: A Biological and Taxonomic Review. Ottawa: Canadian Wildlife Service.

AMERICAN BISON

IDENTIFICATION: An enormous buffalo (up to 61/2 feet high) with massive forequarters, humped shoulders, and (in males) a beard. DISTRIBUTION: Formerly throughout north-central North America, now only in protected areas. HABITAT: Grassland, forests. STUDY AREAS: National Bison Range, Montana; Catalina Island, California; Wind Cave National Park, South Dakota; Wichita Mountain Wildlife Refuge, Oklahoma; Yellowstone National Park, Wyoming; Mackenzie Bison Sanctuary, Northwest Territories, Canada; Waterhen Wood Bison Ranch, Manitoba, Canada; Steel Rose Ranch, Saskatchewan, Canada; subspecies B.b. bison, the Plains Bison, and B.b. athabascae, the Wood Bison.

WISENT

IDENTIFICATION: Similar to American Bison but more slender, less hunched, and with longer legs. DISTRIBUTION: Formerly throughout Europe and central Asia, now only in protected areas; endangered. HABITAT: Forests. STUDY AREAS: Biatowiea Primeval Forest and Reserve, and Niepotomice Reserve, Poland; Polish Academy of Sciences.

AFRICAN BUFFALO

IDENTIFICATION: A huge (II-foot-long), usually black buffalo with massive, upward-curving horns in both sexes. DISTRIBUTION: Sub-Saharan Africa. HABITAT: Savannas, forests. STUDY AREA: Serengeti National Park, Tanzania; subspecies S.c. caffer, the Cape, or Steppe, Buffalo.

Social Organization

Adult males (bulls) in American and European Bison generally live separately from females in groups that may contain up to 12 animals, or else solitarily. Females, their calves, and younger males (generally less than three or four years old) all live together in their own groups. For two months out of the year, female groups aggregate and adult males join these larger herds (which may contain hundreds of animals) for the rutting season. The mating system is “serial monogamy” within an overall framework of polygamy, i.e., males mate with several females, but remain exclusively with each female for a short period. African Buffalo have a similar social organization, living in herds ranging in size from 40–1,500 animals, mostly composed of females and their young in family groups, along with some adult males for part of the year. In addition, about 15 percent of adult males live in smaller bachelor herds, and older males may form peripheral groups.

Description

Behavioral Expression: Male American Bison participate in a variety of homosexual activities. Among younger bulls (less than five years old, particularly one-to-three-year-olds), anal intercourse is common. One male mounts the other with an erect penis and achieves anal penetration; the animal being mounted often facilitates the sexual interaction by positioning his hips or backing toward the other male with his tail lifted to the side. Homosexual copulation lasts on average nearly twice as long as heterosexual mating. The same bull may be mounted several times in succession by one or several other males, but reciprocal mounting is less common, since bulls that mount other males often do not allow themselves to be mounted (although males that are mounted do try to mount their partners). Males that are frequently mounted by other males often exhibit tears in the skin on their back where the mounting bull’s hooves rub on either side of their spine. An identical type of skin abrasion is seen in female Bison that are frequently mounted by males. Homosexual mounting also occurs in a number of other contexts: in Bison (both American and European) and African Buffalo, males sometimes mount each other during play-fighting. An adult male American Bison may also mount another bull at the conclusion of an aggressive interaction. In these two contexts, mounting usually does not involve penetration, although erection of the penis and pelvic thrusting may occur. Sometimes one male will rest his chin on the other’s rump as a prelude to mounting, often while making a soft panting sound. Female homosexual mounting and CHIN-RESTING also occur in Wisent and African Buffalo.

American Bison bulls—especially younger males—also sometimes form a TENDING BOND or consortship with