many Gull studies this chain is collapsed entirely or rendered circular. If homosexuality occurs in a species, and there is also evidence of contamination or pollutants in the environment, the two are automatically assumed to be linked. Homosexual pairing is regarded as a self-evidently “dysfunctional” phenomenon (typically characterized as “reproductive failure”), hence investigators often feel no need to address the actual details of occurrence or causation in the supposed link to toxins. Indeed, the very existence of homosexuality is often subtly equated with environmental contamination and disease even when no actual pollutants have been discovered in the population in question. Ultimately, female pairing is seen as more than simply a behavioral response to certain demographic parameters, which may or may not be indirectly traceable to certain chemical effects. Rather, it assumes the status of a pathological “symptom” directly induced by man-made toxins, symbolizing the larger havoc that people have wreaked on the environment—nature gone awry as a result of human meddling.73 In the end, homosexuality becomes not merely the
In summary, then, unavailability of the opposite sex is, at best, a tenuous “explanation” for the occurrence of animal homosexuality. Aside from having questionable theoretical and methodological underpinnings, this explanation is in many cases simply incompatible with the facts. In other cases, while same-sex activity does occur in contexts where opposite-sex partners are unavailable, many additional factors are involved, and many important questions concerning its occurrence remain to be addressed. Why, for example, do only some individuals or species with sex-skewed populations exhibit homosexual activity, while others manifest a wide variety of alternative behavioral responses? And why have social systems that entail sex segregation or skewed sex ratios—and hence that supposedly “favor” homosexual activities—evolved in the first place, and in so many species? Where it is relevant, unavailability of the opposite sex should be seen as only one of many contributing factors—and the
“The Errors of Their Ways”—Homosexuality as Mistaken Sex Identification
One surprisingly common scientific “explanation” for the occurrence of animal homosexuality is that it simply results from an inability on the part of animals to “properly” differentiate males from females, or else it represents an “indiscriminate” mating urge (i.e., any perceived differences between the sexes are ignored). This explanation is common for some “lower” animals such as insects and amphibians, where there is limited evidence that mating may indeed be random between homosexual and heterosexual.74 However, this type of “indiscriminatory” mating or mistaken sex identification has also been proposed for higher animals, including more than 55 mammals and birds—mostly species in which adult males and females superficially resemble each other (e.g., Cliff Swallows), or in which adolescent or juvenile males supposedly resemble adult females (e.g., Blackbucks, Birds of Paradise).
The gist of this explanation is that when animals engage in homosexuality they are just “making a mistake”—they intend to mate heterosexually, but simply misidentify the sex of their partner because of the physical resemblance between the sexes. Indeed, homosexual interactions are explicitly labeled as “mistakes” or “errors” in several species. Male Cock-of-the-Rock who mount other males have actually been described as “confused” and “bumbling”; the “aberrant sexual behavior” of male Giraffes who mount each other is attributed to their “muddled reflexes”; Black-billed Magpies are characterized as “confused” when they engage in “misdirected” courtship activity with birds of the same sex; and one scientist even suggested that same-sex courtship in Mountain Sheep would probably never occur if males could properly distinguish females from young males.75 Often, the very existence of homosexuality in a species is taken to be “proof” that the animals cannot distinguish males from females: “In many waders the sexes are difficult to distinguish, not only to the observer, but on occasions to the birds themselves, as records of males attempting to copulate with other males have been recorded.” The circularity in this line of reasoning is blatant, since usually no further evidence is offered to indicate that sex misrecognition is prevalent in the species.76 Conversely, the absence of homosexuality in species such as yellow-eyed penguins and its infrequency in Silvery Grebes and Red-faced Lovebirds is offered by scientists as evidence that there are no “problems” with sex recognition in these species.77
Bumbling and Confused?
Quite clearly, sex misrecognition cannot be a widespread “cause” of homosexuality in animals. Same-sex courtship, copulation, and/or pair-bonding occur in numerous species in which males and females look very different from each other: many primates and hoofed mammals, for example, and birds as varied as Ostriches, Grouse, Black-rumped Flameback Woodpeckers, and Scottish Crossbills, to name just a few. Conversely, homosexuality is not found in many animals in which males and females are visually indistinguishable. For example, same-sex activities are not reported for any of the 31 species of North American perching birds in which younger males significantly resemble adult females, while homosexuality occurs in only a small fraction of the hundreds (if not thousands) of birds in which adult males and females are identical to each other.78 Moreover, in the majority of species where homosexuality is attributed to mistaken sex identification, only
In some mammals and birds where homosexuality is attributed to the resemblance between younger males and adult females (e.g., Blackbucks, Manakins, Birds of Paradise), the two sexes are not necessarily identical. Rather, older adolescent and younger adult males exhibit physical characteristics that are actually
Are these (often subtle) differences actually perceptible to the animals themselves? Implicit in many scientists’ pronouncements of sex misrecognition is the assumption that just because males and females look alike to our eyes, they must be indistinguishable to the animals as well. Species differ widely in their visual acuity, color perception, and other sensory abilities, so each case needs to be evaluated individually before any conclusions can be made about animals’ sex recognition abilities—and this has most definitely not been systematically investigated for cases involving animal homosexuality. Nevertheless, one thing is certain: we are only beginning to understand many aspects of animal perception, including heretofore unimagined powers of visual, acoustic, and temporal