Bruce Bagemihl

“Biological Exuberance is, above all, an affirmation of life's vitality and infinite possibilities: a worldview that is once primordial and futuristic, in which gender is kaleidoscopic, sexualities are multiple, and the categories of male and female are fluid and transmutable. A world, in short, exactly like the one we inhabit.”
― Bruce Bagemihl, Biological Exuberance: Animal Homosexuality and Natural Diversity

“In nearly a quarter of all animals in which homosexuality has been observed and analyzed, the behavior has been classified as some other form of nonsexual activity besides (or in addition to) dominance. Reluctant to ascribe sexual motivations to activities that occur between animals of the same gender, scientists in many cases have been formed to come up with alternative "functions". These include some rather far-fetched suggestions, such as the idea that fellatio with male orang-utans is a "nutritive" behavior, or that episodes of cavorting and genital stimulation between male West Indian manatees are "contests of stamina". At various times, homosexuality has been classified as a form of aggression (not necessarily related to dominance), appeasement or placation, play, tension reduction, greeting or social bonding, reassurance or reconciliation, coalition or alliance formations, and "barter" for food or other "favors". It is striking that virtually all of these functions are in fact reasonable and possible components of sexuality - as any reflection on the nature of sexual interactions in humans will reveal - and indeed in some species homosexual interactions do bear characteristics of some or all of these activities. However, in the vast majority of cases these functions are ascribed to a behavior *instead of*, rather than *along with*, a sexual component - and only when the behavior occurs between two males or two females. According to Paul L. Vasey, "While homosexual behavior may serve some social roles, these are often interpreted by zoologists as the primary reason for such interactions and usually seen as negating any sexual component to this behavior. By contrast, heterosexual interactions are invariably seen as being primarily sexual with some possible secondary social functions.”
― Bruce Bagemihl, Biological Exuberance: Animal Homosexuality and Natural Diversity