Biological Exuberance: Animal Homosexuality and Natural Diversity

typically more domineering than any other birds in the flock. Some scientists have suggested that such homosexual pairs may actually be performing the role of “sentinels” or guards for the group as a whole, hence their position at the flock’s “border.” There is also evidence that homosexual Mallard Ducks prefer each other’s company and tend to congregate together: when large numbers of male pairs were brought together in captivity, for instance, they tended to form their own flocks and socialize with each other rather than with heterosexual birds. The reason such flocks are not often seen in the wild, then, may simply be a matter of numbers. Because same-sex pairs tend to make up a minority of the population in this species, it is unlikely that enough homosexual individuals would ever be present together in a wild flock to form their own large groups.³⁸

Nevertheless, the virtual absence of segregated subgroups of homosexual or bisexual individuals in the animal world is probably related at least in part to the general lack of overt hostility toward homosexuality among animals. Of course, multiple factors are undoubtedly involved, as is true for the formation of segregated groups of homosexuals among people. The emergence of “gay ghettos” or subcultures in some human societies is a complex process related to many things besides gaining refuge from persecution, such as the need to find and associate with one’s own kind, the formation of a homosexual “identity,” the development of economic independence, and so on. Nor are such groups merely a defensive response to a hostile society: as with many other minorities, such “ghettos” may begin as a necessary survival tactic but then develop into vital and enriching subcultures of their own. For animal societies we have already seen that many other factors—widespread bisexuality, for instance, or small numbers of animals participating in same-sex activities—can mitigate against the formation of separate groups. Conversely, segregated social units in which homosexual activity takes place often form for reasons that are (initially) unrelated to the sexuality of the animals involved. However, it is striking that both active hostility toward individuals involved in homosexuality and segregation of such individuals are rare occurrences in the animal kingdom. While neither of these social responses to homosexuality is uniquely human (as has been claimed), they are generally uncharacteristic of animal societies. Homosexuality, bisexuality, and transgender are usually as much a part of animal social life as heterosexuality, regardless of their prevalence or frequency of occurrence. In this respect, the vast majority of other creatures have an approach to sexual and gender variance that is decidedly humane, rather than human—and they might even offer us models of how our societies could integrate differently oriented or ambiguously gendered individuals into the fabric of social life.

Homosexual Mallard drakes tend to socialize primarily with each other in their own flocks or “clubs”

Sexual Virtuosos: Heterosexuality and Homosexuality Compared

The complete pattern of human heterosexuality is not found in any other species (social-class differences in sexual behavior, pair-bonding, face-to-face copulation, hidden menstruallestrous cycles, oral and anal intercourse, etc.), although any single aspect of human heterosexuality can be found in some animal species. The same statement can be made about human homosexuality.

—JAMES D. WEINRICH³⁹

It is ironic that this last assertion about how human beings are unique in their sexual behavior should have been made by the same scientist who commented on how rarely such statements of human uniqueness prove to be true. Indeed, now that more detailed and comprehensive information is available about animal homosexuality, it appears that at least three species rival, if not equal, human beings in the variability and “completeness” of their sexual expression: Bonobos, Orang-utans, and Bottlenose Dolphins. For each of the features mentioned above, an identical or equivalent aspect of behavior can be found, at least in a same-sex context. While none of these species has rigidly stratified “social classes,” there are discernible differences in sexual behavior between animals of different ages and social statuses. Homosexual activity is often more frequent in younger, lower-ranking female Bonobos who have recently joined a new troop, for instance, while younger individuals are often “on the top” during female homosexual interactions and “on the bottom” during male homosexual interactions. There is also some evidence that sexual activity between females occurs more often when they belong to distant rank classes. Adolescent or younger-adult Orang-utans participate in same-sex activities more than older, higher-ranking individuals and also exhibit distinctive heterosexual patterns. Younger male Bottlenose Dolphins tend to form their own groups in which same-sex activity is more common than among pair-bonded individuals—while adult males in this species generally do form lifelong bonds with each other.

Although Bonobos do not have exclusive pair-bonding per se, females do form long-lasting bonds with each other that include sexual interactions; adolescent females also typically pair up with an older “mentor” female when they arrive in a new group and engage in sexual activity most frequently with her. Orang-utans often form pairlike consortships in heterosexual contexts, and similar sorts of associations also occur in homosexual contexts. Sexual interactions between female Bonobos usually occur in a face-to-face position, as do heterosexual (and some homosexual) interactions in Orang-utans, as well as most copulations in Bottlenose Dolphins (for the latter, a “belly-to-belly” position is perhaps a more apt characterization). “Hidden estrous cycles” refers to the fact that no overt physical changes signal the various phases of a woman’s sexual cycle. A female Bonobo’s sexual skin swells with her cycle, although it is present for the majority of the cycle and is not associated specifically with ovulation. Bottlenose Dolphins do not generally give any visual cues as to their sexual cycles or timing of ovulation, nor do female Orang-utans.⁴⁰ In any case, all three species engage in sexual activity throughout the female’s cycle the way human beings do, which is one important consequence of concealed sexual cycles in humans. Finally, Bonobos, Orang-utans, and Bottlenose Dolphins all engage in forms of anal and oral sex (the latter including fellatio in Bonobos and Orangs, cunnilingus in Orang-utans, and beak-genital propulsion in Dolphins).⁴¹

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.