Bruce Bagemihl - Biological Exuberance

Male Bonobos also have a wide variety of homosexual interactions. Sometimes, two males mutually stimulate each other’s genitals using a face-to-face position similar to GG-rubbing: one male lies on his back and spreads his legs while the other thrusts on him, rubbing their erections together (in this and all other male homosexual activity, anal penetration is not involved). If there is an age difference between partners, often the younger male will be on the bottom. Occasionally, two males hang from a branch facing each other and engage in what is known as PENIS FENCING, swinging their hips from side to side as they rub their erect penises on each other or cross them as if they were fencing with swords. Another activity is RUMP RUBBING, in which two males stand on all fours in opposite directions, pressing their buttocks against each other and mutually rubbing their anal and scrotal regions. Both males often have erections. Males also mount each other from behind and either mountee or mounter may make thrusting movements. Sometimes the males switch positions, and the mounter may scream or grin in sexual arousal as in lesbian or heterosexual interactions. Bonobo males have also been seen standing on their hind legs, one embracing the other from behind. Other sexual activities include oral sex, or fellatio, in which one male sucks another’s penis at the initiation of either partner (usually seen only in younger males). Manual stimulation of the genitals by a partner also occurs: typically an adolescent male spreads his legs and presents his erect penis to an adult male, who takes the shaft in his hand and caresses it with up-and-down movements. Younger males (and occasionally females) also sometimes give each other openmouthed kisses, often with extensive mutual tongue stimulation. Although males do not appear to form pairlike bonds with sexual partners (as do some females), occasionally two or three males are intimately associated as companions, constantly accompanying each other and foraging together.

Frequency: Homosexual activity is nearly as common as heterosexual activity in Bonobos, accounting for 40–50 percent of all sexual interactions; two-thirds to three-quarters of this same-sex activity is between females (mostly GG-rubbing). Daily life among Bonobos is characterized by numerous relatively brief episodes of sexual activity scattered throughout the day, and homosexual interactions are frequent. Each female participates in GG-rubbing on average once every two hours or so, and some newcomers to a troop do so even more often, on an hourly basis.

Orientation: Virtually all Bonobos are bisexual, interacting sexually with both males and females. In fact, motherhood and homosexual activity are fully integrated among Bonobos, as a female often GG-rubs with another female while her infant is clinging to her belly. Usually same-sex and opposite-sex activities are interspersed or alternated, although both may occur simultaneously during group sexual interactions. Nevertheless, it appears that—among some females at least—homosexual activity is preferred. Although females vary along a continuum, with one-third to nearly 90 percent of their interactions being with partners of the same sex, overall there is often a predominance of homosexual activity. An average of two-thirds of all sexual interactions among females are with other females, and individuals generally have more female than male sexual partners. In addition, females have sometimes been observed consistently ignoring males who are soliciting them for sex, preferring instead to GG-rub with each other.

Variety, flexibility, and frequency of sexual interactions are not limited to contact between Bonobos of the same sex—heterosexual activity is replete with nonreproductive behaviors. Rump rubbing, fellatio, and manual stimulation of the genitals by either sex (including fondling of the scrotum) are all aspects of male-female sexual interactions. In addition, females occasionally mount males from behind (REVERSE mounts), and heterosexual copulation often does not involve penetration and/or ejaculation, but simply mutual rubbing of genitals. Both male and female Bonobos also masturbate (males sometimes using inanimate objects to stimulate themselves). Group sexual activity occurs as well, often with one individual thrusting against a pair who are copulating, and individuals may participate in several bouts of heterosexual activity in rapid succession. Sometimes, because of the frequency and persistence of sexual invitations—often associated with begging for food—individuals (especially males) may even become annoyed and try to avoid further heterosexual interaction. In addition, females occasionally cooperate with one another in harassing and attacking males, in some cases causing severe injuries by holding a male down and biting his ears, fingers, toes, or genitals.

Bonobos mate during all phases of a female’s sexual cycle, and about a third of copulations occur during periods when fertilization is unlikely or impossible. Mating also takes place during pregnancy, sometimes as late as one month before delivery. Both adult males and females interact sexually with adolescents and juveniles (three-to-nine-year-olds). In fact, young females go through a five-to-six-year period sometimes referred to as ADOLESCENT STERILITY (although no pathology is involved) during which they actively participate in heterosexual mating (often with adults) but never get pregnant. Sexual behavior between adults and infants of both sexes is also common—about a third of the time it is initiated by the infant and may involve genital rubbing and full copulatory postures (including penetration of an adult female by a male infant). Another form of nonreproductive sexuality involves contact with other species: younger male Bonobos have occasionally been observed engaging in playful sexual interactions with redtail monkeys (Cercopithecus ascanius ) in the wild.

*asterisked references discuss homosexualityltransgender

*Blount, B. G. (1990) “Issues in Bonobo ( Pan paniscus ) Sexual Behavior.” American Anthropologist 92: 702–14.

*Enomoto, T. (1990) “Social Play and Sexual Behavior of the Bonobo (Pan paniscus) With Special Reference to Flexibility.” Primates 31:469–80.

*Furuichi, T. (1989) “Social Interactions and the Life History of Female Pan paniscus in Wamba, Zaire.” International Journal of Primatology 10:173–97.

*Hashimoto, C. (1997) “Context and Development of Sexual Behavior of Wild Bonobos (Pan paniscus) at Wamba, Zaire.” International Journal of Primatology 18:1–21.

*Hashimoto, C., T. Furuichi, and O. Takenaka (1996) “Matrilineal Kin Relationships and Social Behavior of Wild Bonobos (Pan paniscus): Sequencing the D-loop Region of Mitochondrial DNA.” Primates 37:305–18.

*Hohmann, G. and B. Fruth (1997) “The Function of Genito-Genital Contacts among Female Bonobos (Pan paniscus).” In M. Taborsky and B. Taborsky, eds., Contributions to the XXV International Ethological Conference, p. 112. Advances in Ethology no. 32. Berlin: Blackwell Wissenschafts-Verlag.

*Idani, G. (1991) “Social Relationships Between Immigrant and Resident Bonobo (Pan paniscus) Females at Wamba.” Folia Primatologica 57:83–95.