Bruce Bagemihl - Biological Exuberance

Not only is this true for species such as these where homosexuality has not been reported at all, homosexuality and “pseudoheterosexual” behavior (or transgender) often co-occur in the same species without having anything to do with each other. For example, when confronted aggressively by another male, Chaffinch males sometimes adopt the female’s sexual solicitation posture to prevent an attack, yet this does not trigger homosexual mounting by the other male. Nonbreeding males in this species also sometimes behave like females when trespassing on another male’s territory, but this does not cause the other male to begin courting him. Sexual chases between males, as well as female pairing, do occur in Chaffinches, but in contexts that are unrelated to such opposite-sex mimicry. Rufous-naped Tamarin males perform a “pseudo-female” behavior called upward tail-curling, typically used by females as a prelude to mating; however, males use this display during ambivalent or hostile encounters with females and not during episodes of homosexual mounting with other males. Likewise, Mountain Zebra bachelor stallions imitate the facial expressions and calls of mares in heat when they meet territorial breeding stallions, yet this opposite-sex mimicry does not incite homosexual mounting on the part of the territorial stallion. Rather, same-sex mounting in this species takes place almost exclusively between territorial stallions or between bachelors, rarely if ever between a territorial stallion and a bachelor.

Female Black-crowned Night Herons and Kittiwakes, and male Koalas, occasionally perform courtship behaviors typical of the opposite sex, but in none of these cases are such behaviors associated with the homosexual activity that does occur in these species—in fact, they are typical of animals in heterosexual interactions. 19In Northern Elephant Seals, too, younger males imitate females specifically to gain access to heterosexual mating opportunities, “camouflaging” themselves from older males (who would attack them if they were discovered trespassing among females). Yet this does not specifically trigger homosexual mounting from the older male, and same-sex mounting is typical of contexts outside of female mimicry in this species. In fact, transgendered individuals in Northern Elephant Seals and a number of other species (e.g., Red Deer, Black-headed Gulls, Common Garter Snakes) are often more successful at heterosexual mating than many nontransgendered individuals—in other words, animals that look and/or act like the opposite sex can actually be “more heterosexual” than ones that do not. 20

In a number of animals, some homosexual interactions have characteristics that could be interpreted as involving “pseudoheterosexuality” or transgendered behaviors, yet these constitute only a portion of same-sex activity in the species—and hence, only a partial “explanation,” at best, for the occurrence of these activities. In Tasmanian Native Hens, for example, males adopt a posture following heterosexual copulation that resembles the female’s invitation to mate—yet only one homosexual mounting recorded in this species was apparently triggered by this posture; the rest occurred in other contexts. Rhesus Macaque females who mount other females sometimes display typically “male” behaviors such as various head movements, the way they carry their tails, or other patterns—but just as many females, if not more, do not exhibit these behaviors as a part of their homosexual interactions. 21

Perhaps the most compelling example of how homosexuality, transgender, and gender roles interact in unexpected ways concerns “femalelike” males in Mountain Sheep. In Bighorn and Thinhorn Sheep, being mounted by another male is a typically “male” activity. As described in chapter 1, most males participate in homosexual mounting throughout the year, while females generally refuse to allow males to mount them except for the two or so days out of the year when each of them is in heat. Consequently, transgendered males—rams who associate with females throughout the year (unlike most other males) and exhibit other female behavioral characteristics—do not typically allow other males to mount them. In other words, homosexual activity is characteristic of “masculine” males rather than “feminine” males in these species. Moreover, because same-sex mounting has such primacy in the social organization of these animals, heterosexual activity is actually patterned after homosexual interactions and not the other way around. Females in heat typically imitate the courtship patterns of male homosexual interactions in order to arouse the sexual interest of males—a remarkable example of the exact opposite of a “pseudoheterosexual” pattern. 22

In many animals gender roles of some sort do exist in homosexual interactions, but it is overly simplistic to consider these mere replicas of male and female behaviors. Gendered activities in a same-sex context are never an exact copy of heterosexual roles, and in many cases animals actually exhibit a complex mixture of male and female behavior patterns. This type of gender-role mixing assumes three basic forms: a continuum among individuals, role-differentiated combinations, and behavioral amalgams. 23In some species, individuals vary along a scale or continuum in the extent to which their behaviors in homosexual interactions resemble “male” or “female” patterns. In Kob antelope, for example, some females utilize the full array of courtship patterns typically employed by males, others make use of none or few of these, while most females range somewhere in between these extremes. 24Ruff males fall into four categories along a spectrum of most “malelike” to most “femalelike” in terms of appearance (presence and color of neck ruff, size), aggressive behavior, courtship behaviors, and other characteristics. However, these categories cut across aspects of sexual behavior, including participation in the “male” role of mounter and the “female” role of mountee in homosexual interactions. The most “malelike” males (residents) perform both roles as do the most “femalelike” males (naked-napes), while of the intermediate categories, some participate in both roles (satellite males) and some rarely engage in either (marginal males). In a number of species such as Gorillas, Hanuman Langurs, and Rhesus, Bonnet, and Pig-tailed Macaques, some individuals clearly prefer (or end up mostly participating) in the “mounter” as opposed to the “mountee” roles during same-sex activity, while for other individuals the reverse is true. Yet these patterns represent the two poles of a continuum, since many individuals in these species actually fall along the entire range in terms of their mounting activities. 25

To specifically address the question of “pseudoheterosexual” roles, scientists studying homosexual pairing in Western Gulls made detailed observations regarding whether one partner is more “feminine” and the other more “masculine,” in terms of which courtship, sexual, and territorial behaviors they exhibit. They found that most females employ a mixture of typically male and typically female patterns, although pair-bonds vary in the extent to which there is role differentiation between the partners. In some pairs, one bird performs the majority of mounting and courtship feeding (typically “male” activities) and less “head-tossing” (a typically “female” courtship behavior). In others, there is less of a distinction between the two partners, while in still others the two females participate nearly equally in gendered behaviors. Overall, however, scientists found that both partners in homosexual pairs are more similar to heterosexual females than to males in terms of the amount of time they spend on their nesting territories and their aggressive responses to intruders. 26