Giraffes do it, goats do it, birds and bonobos and dolphins do it. Humans beings–a lot of them anyway–like to do it too, but of all the planet’s species, they’re the only ones who are oppressed when they try.
What humans share with so many other animals, it now appears, is freewheeling homosexuality. For centuries opponents of gay rights have seen same-gender sex as a uniquely human phenomenon, one of the many ways our famously corruptible species flouts the laws of nature. But nature’s morality, it seems, may be remarkably flexible, at least if the new book Biological Exuberance (St. Martin’s Press), by linguist and cognitive scientist Bruce Bagemihl, is to be believed. According to Bagemihl, the animal kingdom is a more sexually complex place than most people know–one where couplings routinely take place not just between male-female pairs but also between male-male and female-female ones. What’s more, same-sex partners don’t meet merely for brief encounters, but may form long-term bonds, sometimes mating for years or even for life.
Bagemihl’s ideas have caused a stir in the higher, human community, especially among scientists who find it simplistic to equate any animal behavior with human behavior. But Bagemihl stands behind the findings, arguing that if homosexuality comes naturally to other creatures, perhaps it’s time to quit getting into such a lather over the fact that it comes naturally to humans too. “Animal sexuality is more complex than we imagined,” says Bagemihl. “That diversity is part of human heritage.”
For a love that long dared not speak its name, animal homosexuality is astonishingly common. Scouring zoological journals and conducting extensive interviews with scientists, Bagemihl found same-sex pairings documented in more than 450 different species. In a world teeming with more than 1 million species, that may not seem like much. Animals, however, can be surprisingly prim about when and under whose prying eye they engage in sexual activity; as few as 2,000 species have thus been observed closely enough to reveal their full range of coupling behavior. Within such a small sampling, 450 represents more than 20%.
That 20% may spend its time lustily or quite tenderly. Among bonobos, a chimplike ape, homosexual pairings account for as much as 50% of all sexual activity. Females especially engage in repeated acts of same-sex sex, spending far more than the 12 or so seconds the whole transaction can take when a randy male is involved. Male giraffes practice necking–literally–in a very big way, entwining their long bodies until both partners become sexually aroused. Heterosexual and homosexual dolphin pairs engage in face-to-face sexual encounters that look altogether human. Animals as diverse as elephants and rodents practice same-sex mounting, and macaques raise that affection ante further, often kissing while assuming a coital position. Same-gender sexual activity, says Bagemihl, “encompasses a wide range of forms.”
What struck Bagemihl most is those forms that go beyond mere sexual gratification. Humboldt penguins may have homosexual unions that last six years; male greylag geese may stay paired for 15 years–a lifetime commitment when you’ve got the lifespan of a goose. Bears and some other mammals may bring their young into homosexual unions, raising them with their same-sex partner just as they would with a member of the opposite sex.
But witnessing same-sex activity and understanding it are two different things, and some experts believe observers like Bagemihl are misreading the evidence. In species that lack sophisticated language–which is to say all species but ours–sex serves many nonsexual purposes, including establishing alliances and appeasing enemies, all things animals must do with members of both sexes. “Sexuality helps animals maneuver around each other before making real contact,” says Martin Daly, an evolutionary psychologist at McMaster University in Ontario. “Putting all that into a homosexual category seems simplistic.”
Even if some animals do engage in homosexual activity purely for pleasure, their behavior still serves as an incomplete model–and an incomplete explanation–for human behavior. “In our society homosexuality means a principal or exclusive orientation,” says psychology professor Frans de Waal of the Yerkes Primate Center in Atlanta. “Among animals it’s just nonreproductive sexual behavior.”
Whether any of this turns out to be good for the gay and lesbian community is unclear. While the new findings seem to support the idea that homosexuality is merely a natural form of sexual expression, Bagemihl believes such political questions may be beside the point. “We shouldn’t have to look to the animal world to see what’s normal or ethical,” he says. Indeed, when it comes to answering those questions, Mother Nature seems to be keeping an open mind.
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Write to Jeffrey Kluger at jeffrey.kluger@time.com