page_title: Bonobo
section_title: Sociosexual behaviour
hierarchical_section_title: Bonobo / Behavior / Social behavior / Sociosexual behaviour
caption_attribution_description: Bonobos mating, Jacksonville zoo, FL.
context_page_description: The bonobo, also historically called the pygmy chimpanzee and less often, the dwarf or gracile chimpanzee, is an endangered great ape and one of the two species making up the genus Pan; the other being the common chimpanzee. Although bonobos are not a subspecies of chimpanzee, but rather a distinct species in their own right, both species are sometimes referred to collectively using the generalized term chimpanzees, or chimps. Taxonomically, the members of the chimpanzee/bonobo subtribe Panina are collectively termed panins.
  The bonobo is distinguished by relatively long legs, pink lips, dark face, tail-tuft through adulthood, and parted long hair on its head. The bonobo is found in a 500,000 km² area of the Congo Basin in the Democratic Republic of the Congo, Central Africa. The species is omnivorous and inhabits primary and secondary forests, including seasonally inundated swamp forests. Because of political instability in the region and the timidity of bonobos, there has been relatively little field work done observing the species in its natural habitat.
  Along with the common chimpanzee, the bonobo is the closest extant relative to humans.
context_section_description: Sexual activity generally plays a major role in bonobo society, being used as what some scientists perceive as a greeting, a means of forming social bonds, a means of conflict resolution, and postconflict reconciliation. Bonobos are the only non-human animal to have been observed engaging in tongue kissing. Bonobos and humans are the only primates to typically engage in face-to-face genital sex, although a pair of western gorillas has been photographed in this position.
  Bonobos do not form permanent monogamous sexual relationships with individual partners. They also do not seem to discriminate in their sexual behavior by sex or age, with the possible exception of abstaining from sexual activity between mothers and their adult sons. When bonobos come upon a new food source or feeding ground, the increased excitement will usually lead to communal sexual activity, presumably decreasing tension and encouraging peaceful feeding.
  Bonobo clitorises are larger and more externalized than in most mammals; while the weight of a young adolescent female bonobo "is maybe half" that of a human teenager, she has a clitoris that is "three times bigger than the human equivalent, and visible enough to waggle unmistakably as she walks". In scientific literature, the female–female behavior of bonobos pressing genitals together is often referred to as genito-genital (GG) rubbing, which is the non-human analogue of tribadism, engaged in by some human females. This sexual activity happens within the immediate female bonobo community and sometimes outside of it. Ethologist Jonathan Balcombe stated that female bonobos rub their clitorises together rapidly for ten to twenty seconds, and this behavior, "which may be repeated in rapid succession, is usually accompanied by grinding, shrieking, and clitoral engorgement"; he added that it is estimated that they engage in this practice "about once every two hours" on average. As bonobos occasionally copulate face-to-face, "evolutionary biologist Marlene Zuk has suggested that the position of the clitoris in bonobos and some other primates has evolved to maximize stimulation during sexual intercourse". The position of the clitoris may alternatively permit GG-rubbings, which has been hypothesized to function as a means for female bonobos to evaluate their intrasocial relationships.
  Bonobo males engage in various forms of male–male genital behavior. The most common form of male–male mounting is similar to that of a heterosexual mounting: one of the males sits "passively on his back [with] the other male thrusting on him", with the penises rubbing together due to both males' erections. In another, rarer form of genital rubbing, which is the non-human analogue of frotting, engaged in by some human males, two bonobo males hang from a tree limb face-to-face while penis fencing. This also may occur when two males rub their penises together while in face-to-face position. Another form of genital interaction (rump rubbing) often occurs to express reconciliation between two males after a conflict, when they stand back-to-back and rub their scrotal sacs together, but such behavior also occurs outside agonistic contexts: Kitamura (1989) observed rump–rump contacts between adult males following sexual solicitation behaviors similar to those between female bonobos prior to GG-rubbing. Takayoshi Kano observed similar practices among bonobos in the natural habitat. Tongue kissing, oral sex, and genital massaging have also been recorded among male bonobos.
  More often than the males, female bonobos engage in mutual genital behavior, possibly to bond socially with each other, thus forming a female nucleus of bonobo society. The bonding among females enables them to dominate most of the males. Adolescent females often leave their native community to join another community. This migration mixes the bonobo gene pools, providing genetic diversity. Sexual bonding with other females establishes these new females as members of the group.
  Bonobo reproductive rates are no higher than those of the common chimpanzee. During oestrus, 
caption: Bonobos mating, Jacksonville Zoo and Gardens.
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