Same-sex behavior has long been observed in other animal species. But scientists, steeped in cultural prejudices against homosexuality, refused to acknowledge what they were seeing. Sometimes the results were comic:
Various forms of same-sex sexual activity have been recorded in more than 450 different species of animals by now, from flamingos to bison to beetles to guppies to warthogs.... For more than a century, this kind of observation was usually tacked onto scientific papers as a curiosity, if it was reported at all, and not pursued as a legitimate research subject. Biologists tried to explain away what they’d seen, or dismissed it as theoretically meaningless—an isolated glitch in an otherwise elegant Darwinian universe where every facet of an animal’s behavior is geared toward reproducing. One primatologist speculated that the real reason two male orangutans were fellating each other was nutritional.
In 1999, Baghemihl published “Biological Exuberance,” a book that pulled together a colossal amount of previous piecemeal research and showed how biologists’ biases had marginalized animal homosexuality for the last 150 years—sometimes innocently enough, sometimes in an eruption of anthropomorphic disgust. Courtship behaviors between two animals of the same sex were persistently described in the literature as “mock” or “pseudo” courtship—or just “practice.” Homosexual sex between ostriches was interpreted by one scientist as “a nuisance” that “goes on and on.” One man, studying Mazarine Blue butterflies in Morocco in 1987, regretted having to report “the lurid details of declining moral standards and of horrific sexual offenses” which are “all too often packed” into national newspapers. And a bighorn-sheep biologist confessed in his memoir, “I still cringe at the memory of seeing old D-ram mount S-ram repeatedly.” To think, he wrote, “of those magnificent beasts as ‘queers’—Oh, God!”
Once upon a time anti-gay bigots argued that homosexual behavior was so filthy and disgusting—so unnatural—that not even animals did it. Now, of course, they argue that homosexual behavior is filthy and disgusting because animals do it. La de da. I'm off to go engage in some "mock courtship" with the boyfriend. I'll spare you the lurid details—don't want to be a nuisance by going on and on about it—but rest assured that our interest in each other is purely nutritional.
The whole piece is fascinating and it's required reading.