Bruce Bagemihl - Biological Exuberance

Frequency: Homosexual activity occurs only sporadically in Moose and Caribou. About a quarter of all male Moose associate together in pairs during at least part of the year.

Orientation: Adult animals that participate in homosexual activities in these two species are, in all likelihood, predominantly heterosexual, albeit with some bisexual capability. Some younger animals—especially among male Moose—may tend toward a less heterosexually oriented bisexuality, since many do not fully participate in heterosexual mating.

In both Moose and Caribou, many animals do not procreate. Caribou males are physiologically capable of breeding when they are a year old, yet most do not mate until they are at least four years old since they cannot successfully compete with the older bucks; a similar pattern is found in Moose. Among Caribou, females without calves may associate with a breeding female as an “assistant mother,” and some even try to “kidnap” or lure a calf away from its biological mother. During severe food shortages, pregnant Caribou females may terminate the breeding process by reabsorbing their embryos, since they would not be able to successfully raise their calves under such conditions. Approximately 8 percent of the male Caribou population consists of older (10+ years), postreproductive males that do not participate in breeding. However, many stags never reach this age, since the life expectancy of males is considerably shorter than that of females, at least in part because of the stresses associated with breeding. In Moose, breeding is also a taxing activity for bulls, who fast completely during the rutting period. Mating can also be a traumatic activity for females: because males in these two species are considerably larger, females often suffer injuries from copulation, sometimes literally collapsing under the weight of a male mounting them. As a result, female Caribou often strongly resist mating attempts and struggle to escape (less than two-thirds of matings are completed), while males may strike them with their antlers to make them submit to mounting. Females, in turn, may use their own antlers to fight back. Female Moose often strike males with their front hooves during the rutting season as well, and are capable of inflicting serious injury. In both species, there is significant segregation of the sexes outside of the breeding season: in Moose, for example, only 10–20 percent of winter groups are cosexual.

Moose and Caribou also participate in a variety of nonreproductive sexual behaviors. Males of both species sometimes try to mount calves, and female Caribou sometimes REVERSE mount males. Heterosexual interactions often involve oral-genital contact—male Moose and Caribou lick the female’s vulva, while female Caribou sometimes lick the male’s penis. About 45 percent of heterosexual mounts in Moose do not involve penetration or ejaculation, and males sometimes mount females up to 14 times in a sequence. In addition, both male Moose and Caribou “masturbate” by rubbing their antlers against vegetation, which often results in sexual stimulation (including erection of the penis and possibly ejaculation).

*asterisked references discuss homosexuality/transgender

Altmann, M. (1959) “Group Dynamics in Wyoming Moose During the Rutting Season.” Journal of Mammalogy 40:420–24.

*Bergerud, A. T. (1974) “Rutting Behavior of Newfoundland Caribou.” In V. Geist and F. Walther, eds., The Behavior of Ungulates and Its Relation to Management , vol. 1, pp. 395–435. IUCN Publication no. 24. Morges, Switzerland: International Union for Conservation of Nature and Natural Resources.

*Bubenik, A. B., G. A. Bubenik, and D. G. Larsen (1990) “Velericorn Antlers on a Mature Male Moose (Alces a. gigas) .” Alces 26:115–28.

Bubenik, A. B., and H. R. Timmerman (1982) “Spermatogenesis of the Taiga-Moose—a Pilot Study.” Alces 18:54–93.

*Denniston, R. H., II (1956) “Ecology, Behavior, and Population Dynamics of the Wyoming or Rocky Mountain Moose, Alces alces shirasi .” Zoologica 41: 105–18.

de Vos, A. (1958) “Summer Observations on Moose Behavior in Ontario.” Journal of Mammalogy 39:128–39.

*Dodds, D. G. (1958) “Observations of Pre-Rutting Behavior in Newfoundland Moose.” Journal of Mammalogy 39:412–16.

*Geist, V (1963) “On the Behavior of the North American Moose ( Alces alces andersoni Peterson 1950), in British Columbia.” Behavior 20:377–416.

Houston, D. B. (1974) “Aspects of the Social Organization of Moose.” In V. Geist and F. Walther, eds., The Behavior of Ungulates and Its Relation to Management , vol. 2, pp. 690–96. IUCN Publication no. 24. Morges, Switzerland: International Union for Conservation of Nature and Natural Resources.

Kojola, I. (1991) “Influence of Age on the Reproductive Effort of Male Reindeer.” Journal of Mammalogy 72:208–10.

*Lent, P. C. (1974) “A Review of Rutting Behavior in Moose.” Naturaliste canadien 101:307–23.

———(1966) “Calving and Related Social Behavior in the Barren-Ground Caribou.” Zeitschrift für Tierpsychologie 23:701–56.

Miquelle, D. G., J. M. Peek, and V. Van Ballenberghe (1992) “Sexual Segregation in Alaskan Moose.” Widlife Monographs 122:1–57.

*Murie, O. J. (1928) “Abnormal Growth of Moose Antlers.” Journal of Mammalogy 9:65.

*Pruitt, W. O., Jr. (1966) “The Function of the Brow-Tine in Caribou Antlers.” Arctic 19:111-13.

———(1960) “Behavior of the Barren-Ground Caribou.” Biological Papers of the University of Alaska 3:1–44.

*Reimers, E. (1993) “Antlerless Females Among Reindeer and Caribou.” Canadian Journal of Zoology 71:1319–25.

Skogland, T. (1989) Comparative Social Organization of Wild Reindeer in Relation to Food, Mates, and Predator Avoidance. Advances in Ethology no. 29. Berlin and Hamburg: Paul Parey Scientific Publishers.

Van Ballenberghe, V, and D. G. Miquelle (1993) “Mating in Moose: Timing, Behavior, and Male Access Patterns.” Canadian Journal of Zoology 71:1687–90.

*Wishart, W. D. (1990) “Velvet-Antlered Female Moose ( Alces alces ).” Alces 26:64–65.

IDENTIFICATION: The tallest mammal (up to 19 feet), with a sloping back, enormously long neck, bony, knobbed “horns” in both sexes, and the familiar reddish brown spotted patterning. DISTAIBUTION: Sub-Saharan Africa. HABITAT: Savanna. STUDY AREAS: Tsavo East and Nairobi National Parks, Kenya; Serengeti, Arusha, and Tarangire National Parks, Tanzania; eastern Transvaal, South Africa; subspecies G.c. tippelskirchi, the Masai Giraffe, and G.c. giralla.

Female Giraffes tend to congregate in groups of up to 15 individuals, including their calves and perhaps a few younger males. Males generally associate in all-male “bachelor” groups, but tend to become solitary as they get older. The mating system is polygamous: mostly a few older males mate with more than one female, but take no part in raising their offspring.

Behavioral Expression: Male Giraffes have a unique “courtship” or affectionate activity called NECKING, which is often associated with homosexual mounting. When necking, two males stand side by side, usually facing in opposite directions, while they gently rub their necks on each other’s body, head, neck, loins, and thighs, sometimes for as long as an hour. Necking sessions are usually initiated with one male assuming a formal posture with his neck held rigid and upright. One male may also affectionately lick the other’s back or sniff his genitals during necking. Necking Giraffes also sometimes swing their necks at each other in what has been described as a “stately dance” or a form of play-fighting (although they rarely hit, and virtually never injure, each other). Necking usually leads to sexual arousal: one or both males develop erections, and occasionally one might exhibit a curling of the lip similar to the FLEHMEN response seen in heterosexual courtships (associated with sexual arousal and testing sexual “readiness”). Sometimes after necking for 15 minutes or so, one male suddenly stops and “freezes” with his neck stretched forward, which is thought to indicate intense sexual excitement approaching orgasm. Males also commonly mount each other with erect penises during or following bouts of necking and probably reach orgasm (sometimes liquid—presumably semen—can be seen streaming from their penises). At times, groups of four or five males will gather to neck and mount each other, and males may mount several individuals in quick succession or the same male as many as three times in a row. Females also occasionally mount each other, but they do not participate in necking.