Sex without Purpose: Pleasure and Nonreproduction

Suzie stood with her back to Unk and she leaned her upper torso downward. He proceeded to manipulate her genitalia. That same day, … Suzie allowed subadult Smitty to lick her clitoris …. Observations … indicated that Suzie may experience orgasm … a shudder coursed through her entire body and then she became rigid.

—GREYSOLYNNE J. FOX, Social Dynamics in Siamang ¹⁴¹

Even when males and females can overcome the considerable hurdles standing in the way of mating, they often engage in sexual activities that do not lead to reproduction. Several different forms of such “purposeless” sexual behavior can be identified, the most common being heterosexual sex that involves partners or situations where fertilization is impossible. As previously mentioned, many animals routinely mate (or engage in other sexual activities) outside of the breeding season or when the female is not ovulating—including during menstruation and pregnancy (or, in birds, during the incubation period). Not only is this found in a wide variety of animals—in mammals, for example, among various primates, hoofed mammals, carnivores, marsupials, rodents, and so on—but such nonprocreative sexual activity frequently constitutes a significant portion of all sexual behavior. In Common Murres, for instance, about half of all copulations in some populations occur during times when fertilization is not possible, while in Proboscis Monkeys and golden lion tamarins, a peak in sexual activity often occurs during pregnancy. ¹⁴² About half of all pregnant or menstruating Rhesus Macaques are sexually active, and some males mate with pregnant females as often as they do with ovulating females. In fact, sexual activity sometimes occurs during or shortly after birth in this species: males have been observed mounting females who just gave birth, while female attendants occasionally masturbate themselves while watching a female in labor. The birth process itself also stimulates sexual interest (courtship, mounting) in several species of hoofed mammals, including Mountain Goats, addax antelopes, and wildebeest.¹⁴³ In none of these cases can the “function” of such sexual activity be procreation. Heterosexual behavior also occurs among sexually immature animals, between adults and juveniles, between genetically related animals, between members of different species, and sometimes even between live and dead animals—all instances in which reproduction is not optimized (if not altogether impossible).¹⁴⁴

Multiple copulations—in which animals mate far in excess of the amount required for fertilization—are also widespread. Several species of wild cats and birds of prey, for instance, have astonishingly high copulation rates. Lions may mate up to 100 times a day during the breeding season (or as much as 1,500 times for each litter produced), while heterosexual pairs of goshawks and American kestrels mate 500-700 times for each clutch of eggs they produce.¹⁴⁵ Oystercatcher pairs also copulate about 700 times each breeding season, while female Kob antelopes may each experience several hundred heterosexual mounts during a 24-hour visit to the mating grounds.¹⁴⁶ In addition, animals of some species (e.g., Spinner Dolphins, Gray and Bowhead Whales, Herons, Swallows) engage in group sexual activity in which only a small subset of the participants (if any) are actually passing on their genes and reproducing.

Specific nonprocreative heterosexual practices in the animal world are many and varied, and they often parallel homosexual behaviors as well as the wide variety of nonreproductive sexual practices found in humans. To begin with, mounting that does not involve full genital contact—sometimes described as “symbolic,” “display,” or “noncopulatory” mounting—is widespread. For every “full” copulation in Kob antelopes, for instance, an average of three mounts without erection and six mounts with an erection but no penetration are performed by the male.¹⁴⁷ Reverse mounting—in which the female mounts the male, usually without mutual genital contact—also occurs in a wide variety of species, and sometimes involves “reciprocal” mounting or sequential exchange of positions between the male and the female. ¹⁴⁸ In some species, males occasionally mount females from the side or in other positions that do not involve penetration or genital contact: for example, Japanese Macaques, Waterbuck, Mountain Sheep, Takhi, Collared Peccaries, Warthogs, Koalas, Ruffs, Hammerheads, and Chaffinches. Many other types of nonprocreative sexual acts occur in mammals: various forms of oral sex (including fellatio, genital licking, and beak-genital propulsion); stimulation of a partner’s genitals with the hands or other appendages (such as flippers), including vaginal penetration with the fingers (in primates); anal stimulation, including penetration with fingers or oral-anal contact (e.g., Orang-utans), rump rubbing (e.g., in Bonobos and Common Chimpanzees), and even heterosexual anal intercourse (e.g., in Orang-utans).

Masturbation also occurs widely among animals, both male and female. A variety of creative techniques are used, including genital stimulation using the hand or front paw (primates, Lions), foot (Vampire Bats, primates), flipper (Walruses), or tail (Savanna Baboons), sometimes accompanied by stimulation of the nipples (Rhesus Macaques, Bonobos); auto-fellatio, or licking, sucking, and/or nuzzling by a male of his own penis (Common Chimpanzees, Savanna Baboons, Vervet Monkeys, Squirrel Monkeys, Thinhorn Sheep, Bharal, Aoudad, Dwarf Cavies); stimulation of the penis by flipping or rubbing it against the belly or in its own sheath (White-tailed and Mule Deer, Zebras, and Takhi); spontaneous ejaculations (Mountain Sheep, Warthogs, Spotted Hyenas); and stimulation of the genitals using inanimate objects (found in several primates and cetaceans; see chapter 2 for further discussion). Many birds masturbate by mounting and copulating with tufts of grass, leaves, or mounds of earth, and some mammals such as primates and Dolphins also rub their genitals against the ground or other surfaces to stimulate themselves. One fairly unusual form of (indirect) genital stimulation occurs in some hoofed mammals. Among male Red Deer, Moose, Wapiti, and other species of Deer, the antlers are erotic organs that can result in sexual arousal and even ejaculation when they are rubbed. In addition to occasionally stimulating each other this way, males of these species often stimulate themselves by rubbing their antlers in clumps of vegetation.¹⁴⁹

Sex for pleasure: masturbation in a male Walrus (left) and a White-tailed Deer

Masturbation in female mammals, as well as heterosexual and homosexual intercourse (especially in primates), often involves direct or indirect stimulation of the clitoris (as in the description at the beginning of this section of oral sex among Siamangs, a primate species). This organ is present in the females of all mammalian species and several other animal groups, yet it has generally elicited a uniform reaction throughout much of scientific history: stunned (and embarrassed) silence. ¹⁵⁰ This is due not only to the general hush surrounding female sexuality, but because the clitoris poses serious challenges to conventional biological theories. Its only “function” appears to be sexual pleasure, and the notion of pleasure in animals, particularly as it relates to the phenomenon of female orgasm, is a difficult one for biologists to come to terms with. Scientists have been remarkably reticent on the subject, refusing even to believe that female animals can experience orgasm until the phenomenon was “proven” with detailed observations and experimental studies on monkeys.¹⁵¹

Even after it was “verified,” a debate about the “function” of the female orgasm erupted in the scientific community and continues nearly unabated to this day.¹⁵² When a male animal has an orgasm—i.e., ejaculates—this is typically explained as the “mechanism” that insures sperm is transferred to the female—not as the pursuit of sexual pleasure. But no such mechanistic “explanation” is available for the female orgasm or clitoris. Most current biological discussion of the female orgasmic response attempts to justify its existence in terms of how sexual pleasure might “encourage” or contribute to breeding or social bonding, rather than seeing it as something inherently valuable that requires no further “justification.” As always, female sexuality—and sexual pleasure in general—is assumed not to exist until proven otherwise. Once “proven” it requires a “function” or “purpose” rather than having intrinsic worth—a striking echo of the presumption of heterosexuality in biology and the need to find an “explanation” for the occurrence of homosexuality. ¹⁵³