Biological Exuberance: Animal Homosexuality and Natural Diversity

In most species the same courtship behaviors are used in both homosexual and heterosexual interactions. Sometimes, however, same-sex courtship involves only a subset of the movements and behaviors found in opposite-sex displays. For example, when Canada Geese court each other homosexually, they perform a neckdipping ritual also found in heterosexual courtships, but do not adopt the special posture that males and females use after mating. In animals like the Western Gull or Kob antelope, individuals vary as to how many courtship behaviors they use in same-sex interactions. Some exhibit only one or two of the typical courtship postures and movements, while others go through the entire elaborate courtship sequence. Perhaps most interesting are those creatures that have a special courtship pattern found only in homosexual interactions. Male Ostriches, for example, perform a unique “pirouette dance” only when courting other males, while female Rhesus Macaques engage in courtship games such as “hide-and-seek” that are unique to lesbian interactions.

Kisses, Wuzzles, and Necking: Affectionate Behaviors

Many animals of the same sex touch each other in ways that are not overtly sexual (they do not involve direct contact of the genitals) but that do nevertheless have clear sexual or erotic overtones. These are referred to as affectionate activities and are found in nearly a quarter of the animals in which some form of homosexual activity occurs. Although many of these behaviors (grooming, embracing, play-fighting) can occur in other contexts, their erotic nature in a same-sex context is usually obvious: the two animals may be visibly sexually aroused, the behavior may directly precede or follow homosexual copulation or courtship, or the affectionate activity may occur in a same-sex pair-bond.

One type of affectionate activity is simple grooming or rubbing. Male Lions “head-rub” and roll around with each other before having sex together; Bats such as Gray-headed Flying Foxes and Vampire Bats engage in erotic same-sex grooming and licking; male Mountain Sheep rub their horns and faces on other males, sometimes becoming sexually aroused; Whales and Dolphins stroke and rub each other with their flippers or tail flukes, as well as rub bodies together; while numerous primates such as Apes, Macaques, and Baboons frequently caress and groom each other in both sexual and nonsexual contexts. A few birds such as Humboldt Penguins, Pukeko, Black-billed Magpies, and Parrots also indulge in preening—the avian equivalent of grooming—in their homosexual interactions or pair-bonds.

Some animals also “kiss” each other: male African Elephants, female Rhesus Macaques, male West Indian Manatees and Walruses, female Hoary Marmots, and male Mountain Zebras (among others) all touch mouths, noses, or muzzles during their homosexual encounters. Even some birds, such as Black-billed Magpies, engage in mutual beak-nibbling or “billing” as part of same-sex courtship. In primates, kissing (in both homosexual and heterosexual contexts) can bear a startling resemblance to the corresponding human activity: a number of species such as Squirrel Monkeys and Common Chimpanzees engage in full mouth-to-mouth contact, while male Bonobos kiss each other with “passionate” openmouthed kisses with considerable mutual tongue stimulation.

Numerous species of Monkeys and Apes also “hug” or embrace same-sex partners in homosexual contexts (usually face-to-face, although male Bonobos and Vervets also embrace while standing in a front-to-back position). Among non-primates, female Bottlenose Dolphins clasp each other during homosexual activity, male West Indian Manatees embrace one another underwater, while Gray-headed Flying Foxes wrap their wing-membranes around same-sex partners while stimulating each other. A striking form of same-sex embracing is the “sleeping huddle” found in Stumptail and Bonnet Macaques: a pair of males often sleep together in a front-to-back position, one male wrapping his arms around the other and sometimes even holding on to his partner’s penis. A similar sleeping arrangement occurs, surprisingly, among male Walruses, who often sleep in same-sex pairs or extended “chains” of males, all clasping each other in a front-to-back position as they float at the water’s surface.

Two younger male Bonobos kissing

(PHOTO BY FRANS DE WAAL)