Bruce Bagemihl - Biological Exuberance

Sometimes certain aspects of homosexual activity are excluded or arbitrarily eliminated from an overall analysis or tabulation—often resulting in a distorted picture of same-sex interactions (regardless of whether the omission is deliberate or well-motivated). For instance, a female Western Gull who exhibited the most overt sexual activity with her female partner was “not included in the tabulated statistics” of a study comparing heterosexual and homosexual behaviors. By failing to incorporate data from this individual (intentionally or not), researchers undoubtedly helped foster the (now widely cited) impression that sexual activity is a uniformly negligible aspect of female pairing in this species. Along the same lines, scientists surveying pair formation in Black-crowned Night Herons only tabulated homosexual couples that they considered to be “caused” by the “crowded” conditions of captivity. They ignored a male pair whose formation could not be attributed to such conditions and also overlooked the fact that such “crowded” conditions regularly occur in wild colonies of the same species. And all data concerning same-sex pairs or coparents in Laughing Gulls, Canary-winged Parakeets, Greater Rheas, and Zebra Finches were excluded from general studies of pair-bonding, nesting, or other behaviors in these species. 51

The significance of homosexual activity is sometimes also downplayed in discussions of its prevalence or frequency. Certainly many variables must be considered when trying to quantify same-sex activity, and the task is rarely straightforward (as we saw in chapter 1). Nevertheless, in some instances homosexual frequency is interpreted or calculated so as to give the impression that same-sex activity is less common than it really is or else is de-emphasized in terms of its importance relative to other species. In Gorillas, for example, homosexual activity in females is classified as “rare” because investigators observed it “only” 10 times on eight separate days. However, these figures are incomplete unless compared with the frequency of heterosexual interactions during the same period. In fact, 98 episodes of heterosexual mating were recorded during the same period, which means that 9 percent of all sexual activity was homosexual—a significant percentage when compared to other species. 52Similarly, investigators studying lesbian pairs in Western Gulls state, “We have estimated female-female pairs make up only 10—15 percent of the population” (emphasis added), when in fact this is one of the higher rates recorded for homosexual pairs in any bird species (and certainly the highest rate reported at that time). Homosexual mounting in female Spotted Hyenas is claimed to be much less frequent than in other female mammals, yet no specific figures are offered; the one species that is mentioned in comparison is the Guinea Pig, a domesticated rodent that is not necessarily the best model for a wild carnivore. 53

It is also important to consider the behavioral type and context when evaluating frequency. Homosexual copulations in Tree Swallows, for example, have been characterized as “exceedingly rare” because they have been observed only infrequently and are much less common than heterosexual matings between pair-bonded birds. However, homosexual copulations are nonmonogamous matings (i.e., they typically involve birds that are not paired to one another and may even have heterosexual mates); it is insufficient in this case to compare the frequency rates of two different kinds of copulation (within-pair and extra-pair). In fact, the more comparable heterosexual behavior—nonmonogamous copulations involving males and females—are also “rarely” seen. Early observers considered them to be exceedingly uncommon (or nonexistent), while a later study documented only two such matings during four years of observation, and subsequent research has yielded consistently low levels of observed promiscuous (heterosexual) copulations. Yet scientists now know that such matings must be common because of the high rates of offspring resulting from them—in some populations, more than three-quarters of all nestlings (as verified by DNA testing). Thus, it is likely that the frequency of homosexual nonmonogamous matings has been similarly underestimated. 54

Many scientists, on first observing an episode of homosexual activity, are also quick to classify the behavior as an exceptional or isolated occurrence for that species. In contrast, a single observed instance of heterosexuality is routinely interpreted as representative of a recurrent behavior pattern, even though it may occur (or be observed) extremely rarely or exhibit wide variation in form or context. This sets up a double standard in assessing and interpreting the prevalence of each behavior type, especially since opposite-sex mating can be a less than ubiquitous or uniform feature of an animal’s social life (see chapter 5). It also conflicts with the patterns established for other species. In repeated instances, homosexual activity was initially recorded in only one episode, dyad, or population (and usually interpreted—or dismissed—as an isolated example), but was then confirmed by subsequent research as a regular feature of the behavioral repertoire of the species—often spanning many decades, geographic areas, and behavioral contexts. 55It is no longer possible to claim that homosexuality is an anomalous occurrence in a certain species simply because it has only been observed a handful of times.

In some cases, conflicting verbal assessments of the prevalence of homosexual activity are offered by the same investigators, when the actual quantitative data show a relatively high occurrence. Homosexual courtship/copulation in Pukeko, for example, is described as being both “common” and “relatively rare”—the actual rate of 7 percent of all sexual activity is in fact fairly high compared to other species (and the same-sex courtship rates are even higher). Likewise, a report on Black-headed Gulls states, “Homosexual pairs were also rare,” then a few pages later counterasserts that “male-male bonds occurred rather commonly”—and at approximately 16 percent of all pairs observed, the actual rates support the latter interpretation more than the former. 56Not only are these assessments inconsistent and unfair with regard to the observed rates of homosexuality, they also run counter to a standard cross-species measure of heterosexual frequency. Although there is no absolute or universal criterion for what is “rare” or “common,” biologists do recognize a “threshold” of 5 percent as being significant where at least one heterosexual behavior is concerned—polygamy. When this mating system is exhibited by only a minority of the population (as is true in many birds, for example), it is nevertheless considered to be a “regular” feature of the species’ behavioral repertoire when its incidence reaches 5 percent. This is certainly far less than the rate of homosexuality in many species where same-sex behavior is regarded as “uncommon” or “exceptional.” 57

In a vivid example of the marginalization that often surrounds discussion of animal homosexuality, scientists sometimes find their own descriptions of same-sex activity published with “amendments,” “asides,” or “explanations” inserted by journal or reprint editors who are uncomfortable with the content or appellation. For example, one ornithologist’s description of homosexual activity in House Sparrows and Brown-headed Cowbirds was embellished with a note from the editor of the journal where it appeared, offering several implausible “reinterpretations” of the behavior that eliminated any sexual motivation. Likewise, when descriptions of homosexual activity in Baboons from the 1920s were reprinted nearly half a century later, a scientist who penned the introduction to the new edition felt compelled to annotate the offending passages with the “modern” viewpoint that such activity is not really homosexual. And editors of the journal British Birds scrambled to try to “explain” a case of homosexual pairing in male Kestrels as actually involving a “male-plumaged female” (i.e., a female bird that looked exactly like a male). They added in their published postscript to the article that this putative plumage variation was, in their opinion, “of much more interest than the copulation or attempted one between the two males” that was the primary focus of the author’s report. 58