Bruce Bagemihl - Biological Exuberance

Some nonsexual interpretations of homosexual activity discussed in the previous chapters hinge on the indirect contribution of homosexuality to heterosexuality. For example, it has been suggested that homosexuality reinforces group cohesion and social bonds between individuals, thereby improving their well-being and allowing them, ultimately, to reproduce more successfully. It has also been claimed that homosexual “alliances” between animals improve their chances of gaining heterosexual copulations. 54Some scientists have been even bolder in their view of the connection between homosexual and heterosexual activity, regarding the two to be directly related or even essentially continuous: same-sex activity is seen as simply an alternative breeding strategy adopted by some animals, or a way to attract or acquire partners of the opposite sex. 55It has been proposed, for example, that female Rhesus Macaques sometimes form homosexual consortships to gain access to a male who is himself consorting with their female partner, or that male Bottlenose Dolphins form pairs with each other to seek out female partners. 56

Another standard “explanation” for homosexual activity among females, especially mammals, is that it attracts males and stimulates them to mate heterosexually. It has also been suggested that female mammals mount each other primarily when one or both partners are in heat, and hence homosexual activity acts as a signal to males of when females are ready to mate. A variation on the notion of homosexuality as a stimulant for heterosexuality is the speculation that males stimulate their own libidos by engaging in same-sex activity (rather than attracting female partners). For example, erotic fighting in African Elephants (during which both participants become sexually aroused) is claimed to stimulate the males so that they can then go out and seek female partners, while male homosexuality in Greenshanks and Golden Plovers is claimed to stimulate and strengthen the birds’ heterosexual drive. 57

Most of these rather fanciful speculations are not based on any systematic evidence, and in fact there are many arguments against such interpretations. To begin with, homosexual activity in many species is not restricted to the breeding season (i.e., the time when it could “stimulate” heterosexual mating) or to females who are in heat. In more than a third of the mammals and birds for which information is available concerning the chronology of homosexual activity, it occurs either year-round (i.e., both in the breeding and nonbreeding seasons or in females regardless of whether they are in heat or fertile), or else only during the nonbreeding season. 58In some cases, the majority of homosexual activity occurs when females cannot conceive, e.g., when they are pregnant (some populations of Japanese Macaques) or during nonfertilizable stages of their cycle (Hanuman Langurs), 59and therefore it cannot contribute to heterosexual mating.

Furthermore, even when homosexual activity does take place during the breeding season or at times when females can conceive, cases where it attracts members of the opposite sex or stimulates heterosexual mating activity are the exception, not the rule. In most species, other animals are entirely disinterested, nonchalant, or “underwhelmed” by any same-sex activity they may happen to observe (as discussed in chapter 2). Members of the opposite sex are often entirely absent from the vicinity (Hanuman Langurs) or may even stay away or leave when homosexual activity is taking place (Guianan Cock-of-the-Rock) or be chased away or ignored when they attempt to interact with animals engaging in homosexual activity (Japanese Macaques, Hanuman Langurs). Moreover, in many species homosexual alliances do not actually “improve” their participants’ chances at gaining opposite-sex partners, and the reproductive advantages of same-sex coalitions are often questionable. Male Calfbird companions who display together, for example, do not attract females, nor are they more successful at acquiring mating territories or overcoming rivals than “single” males. Male Cheetahs living in same-sex bonded coalitions (pairs or trios) are no more likely to encounter females than are single males (even though the standard interpretation of such bonding is that it enhances males’ reproductive opportunities and access to opposite-sex partners). They may in fact suffer reduced chances of heterosexual mating (and lowered reproductive output) because of competition or direct interference from their companions. Likewise, although coalitions of male Savanna Baboons sometimes cooperate in obtaining or defending female partners, one researcher points out that this is true for only one-quarter to one-third of all such alliances, concluding that most male partnerships serve many purposes besides obtaining mates and may even lack a recognizable “function.” 60

The case for male pair-bonding being solely a breeding strategy in Bottlenose Dolphins is also far from definitive. Pairing or “coalition” formation between males of this species is often interpreted—and widely cited—as a means whereby the animals obtain heterosexual mates. Although pairs (and trios) of Bottlenose males may cooperatively seek out and herd females for purposes of mating in some populations (e.g., Australia), this is not a uniform aspect of such partnerships, and in many cases it has yet to be documented. Heterosexual matings resulting from such associations have not in fact been observed in the Florida population where the most extensive study of male pairing has been conducted, nor in Ecuador, where it has recently been suggested that paired males may compete for females. In Australia, where herding and mounting of females by paired males have been observed, no “full” copulations involving penetration have actually been documented, so the reproductive status of this behavior is not clear. Moreover, nearly 38 percent of the animals herded by paired males in Australia were not definitvely sexed: researchers simply assumed that they were females. In fact, bonded males in other populations seek out male rather than female sexual partners in at least some contexts. In the Bahamas, pairs or coalitions of adult male Bottlenose Dolphins herd and chase Atlantic Spotted Dolphins; they typically pursue homosexual activities (including full penetrative copulation with other males) during these interspecies encounters. Finally, even if bonded males assist each other in obtaining heterosexual mates, this does not preclude a homosexual dimension to such partnerships—sequential and simultaneous bisexuality are, after all, prominent in this species. Same-sex pairs can form as long as ten to fifteen years before breeding activity commences, and homosexual activity may exist concurrently with heterosexual activity in such pairs once they do reach breeding age. 61

One species in which same-sex activity among males sometimes does attract females is the Ruff. As already noted, however, homosexual behavior in this bird is not limited to contexts in which it might increase opportunities for heterosexual mating. It also occurs among nonbreeding males, when females are not present, and during the nonbreeding season. Similarly, homosexual activity in female Squirrel Monkeys sometimes does arouse the attentions of males. However, it is clear that the participating females engage in such behavior regardless of whether it draws males and even rebuff the advances of males who approach them during such activity. Sometimes heterosexual behavior serves as a stimulant for homosexual activity and not the other way around. Stumptail Macaques, aroused by the sight of heterosexual activity, often initiate same-sex interactions, while in Wolves, Savanna (Yellow) Baboons, and Mountain Sheep, animals watching heterosexual mating often become excited and engage in homosexual activities. 62