Biological Exuberance: Animal Homosexuality and Natural Diversity

One area relating to sexual variability where animal and human homosexuality have been claimed to be comparable, rather than different, concerns the variety of sexual acts or positions used in homosexual as opposed to heterosexual contexts. Masters and Johnson found that gays and lesbians in long-term relationships often had better sexual technique and more variety in their sex lives than married heterosexuals. James Weinrich has suggested a parallel to this observation among animals, claiming that animals that engage in same-sex activity are, in a sense, sexual “virtuosos,” employing a wider range of sexual behaviors, positions, or techniques than do their heterosexual counterparts.⁴² Although the validity of this claim with respect to human beings cannot be directly addressed here, its accuracy with respect to animals can be assessed—and it appears that in this case the situation is considerably more complex than previously supposed.

It is certainly true that homosexual repertoires have a wider range of sexual acts than heterosexual repertoires in a number of species. In Stumptail and Crab-eating Macaques, for instance, oral sex and mutual masturbation occur primarily, if not exclusively, between same-sex partners. Male Bonobos have a form of mutual genital rubbing known as penis fencing that is unique to same-sex interactions. Male West Indian Manatees employ a wider variety of positions and forms of genital stimulation during sex with each other than do opposite-sex partners. Various types of anal or rump stimulation (besides mounting or intercourse) occur in homosexual but not heterosexual contexts in several Macaque species, Siamangs, and Savanna Baboons. Only same-sex partners participate in reciprocal mounting in at least 15 species, including Bonnet Macaques, Mountain Zebras, Koalas, and Pukeko.⁴³

This does not, however, appear to be part of an overall pattern, especially where sexual activities other than mounting or intercourse are concerned. For example, of the 36 species (exhibiting homosexual behavior) in which some form of oral sex is practiced, in only 10 (28 percent) of these is oral-genital stimulation limited to homosexual contexts, and in some cases (e.g., Rhesus Macaques, Caribou, Walruses, Lions) genital licking is a uniquely heterosexual act. Similarly, manual stimulation of the genitals or masturbation between partners is limited to same-sex interactions in 15 of the 27 species (55 percent) where this behavior occurs; in the remaining animals, both heterosexual and homosexual (or, in some cases, only heterosexual) partners are involved. Even anal or rump stimulation (besides intercourse) is found in heterosexual contexts in half of the species (6 of 12) that engage in such activities. Combining these observations, we find that a variety of sexual acts are part of both heterosexual and homosexual repertoires in the majority of cases, with behaviors unique to same-sex interactions occurring only in about 40 percent of the cases.