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Conservation status: Endangered[2]
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Family: Hominidae
Genus: Pan
Species: P. paniscus
Binomial name
Pan paniscus
Schwarz, 1929
Bonobo distribution
Bonobo distribution

The Bonobo (IPA: /bəˈnoʊboʊ/, Pan paniscus), until recently usually called the Pygmy Chimpanzee (and less often the Dwarf or Gracile Chimpanzee),[3] is one of the two species making up the chimpanzee genus, Pan. The other species in genus Pan is Pan troglodytes, or the Common Chimpanzee. Although the name "chimpanzee" is sometimes used to refer to both species together, it is usually understood as referring to the Common Chimpanzee.

German anatomist Ernst Schwarz is credited with having discovered the Bonobo in 1928, based on his analysis of a skull in the Tervuren museum in Belgium that had been thought to have belonged to a juvenile chimpanzee. Schwarz published his findings in 1929. In 1933, American anatomist Harold Coolidge offered a more detailed description of the Bonobo, and elevated it to species status. The species is distinguished by relatively long legs, a matriarchal culture, and the prominent role of sexual activity in its society.

This primate is mainly frugivorous, but supplements its diet with leaves and sometimes small vertebrates (such as flying squirrels and infant duikers[4]) and invertebrates.[5]


Common name

The name Bonobo first appeared in 1954, when Edward Tratz and Heinz Heck proposed it as a new and separate generic term for pygmy chimpanzees. The term has been variously reported[How to reference and link to summary or text] as being a word for "chimpanzee" or "ancestor" in the Bantu language. Another suggestion is that the name is a misspelling of the name of the town of Bolobo on the Congo River, which has been associated with the collection of chimps in the 1920s.[6]


The scientific name for the Bonobo is Pan paniscus. Initial genetic studies have characterised their DNA as more than 98% identical to that of Homo sapiens.[7] More recent studies have shown that chimps are more closely related to humans than to gorillas.[8] The most recent genetic analyses of chimpanzee and human genetic similarity come from whole genome comparisons and have shown that the differences between the two are more complex both in extent and character than the historical 98% figure suggests. In the seminal Nature paper reporting on initial genome comparisons, researchers identified thirty-five million single-nucleotide changes, five million insertion/deletion events, and a number of chromosomal rearrangements which constituted the genetic differences between chimps and humans, covering ~5% of both genomes.[9] While many of these analyses have been performed on the Common Chimpanzee rather than the Bonobo, the differences between the two chimpanzee species are unlikely to be substantial enough to affect the Pan-Homo comparative data significantly.

But there is still controversy. Scientists such as Morris Goodman[10] of Wayne State University in Detroit argue that the Bonobo and Common Chimpanzee are so closely related to humans, their genus name should also be classified with the Human genus Homo: Homo paniscus, Homo sylvestris, or Homo arboreus. An alternative philosophy suggests that the term Homo sapiens is actually the misnomer, and that humanity should be reclassified as Pan sapiens. In either case, a name change of the genus is problematic because it complicates the taxonomy of other species closely related to humans, including Australopithecus.

Recent DNA evidence suggests the Bonobo and Common Chimpanzee species effectively separated from each other less than one million years ago.[11][12] The chimpanzee line split from the last common ancestor with the Human approximately four to six million years ago. Because no species other than Homo sapiens has survived from the human line of that branching, both Pan species are the closest living relatives of humans, and cladistically exactly equally close to humans.

Physical characteristics

Bonobo 009


The Bonobo is more gracile (slight in form) than the Common Chimpanzee. Its head is smaller than that of the Common Chimpanzee with less prominent eyebrow ridges. It has a black face with pink lips, small ears, wide nostrils, and long hair on its head. Females have slightly more prominent breasts in contrast to the flat breasts of other female apes, though not as prominent as those of humans. The Bonobo also has a slim upper body, narrow shoulders, thin neck, and long legs compared with the Common Chimpanzee. The Bonobo walks upright about 25% of the time during ground locomotion. These characteristics, and its posture, gives the Bonobo a more human-like appearance than that of the Common Chimpanzee (see: bipedal Bonobos). Moreover, the Bonobo has highly individuated facial features, as humans do, so that one individual can look significantly different from another, adapted for visual recognition in social interaction.

Psychological characteristics

Frans de Waal, one of the world's leading primatologists, states that the Bonobo is often capable of altruism, compassion, empathy, kindness, patience and sensitivity.

Recent observations in the wild indicate that the males among the Common Chimpanzee communities are extraordinarily hostile to males from outside of the community. Parties of males 'patrol' for the unfortunate neighbouring males who might be traveling alone, and attack those single males, often killing them. (Some researchers have suggested, however, that this behaviour has been caused by a combination of human contact and interference and massive environmental stress caused by deforestation and a corresponding range reduction.[13]) This does not appear to be the behavior of the Bonobo males or females, both of which seem to prefer sexual contact over violent confrontation with outsiders. The Bonobo lives in different areas from the more aggressive Common Chimpanzee. Neither of the species swims, and they sometimes inhabit ranges on opposite sides of the great Congo River. It has been hypothesized that Bonobos are able to live a more peaceful lifestyle in part because of an abundance of nutritious vegetation in their natural habitat, allowing them to travel and forage in large parties.

The popular image of the Bonobo as a "peaceful ape" has come under fire. Accounts exist of Bonobos in zoos mutilating one another and engaging in bullying. These incidents may be due to the practice in zoos of separating mothers and sons. Bonobo society is dominated by females, and severing the lifelong alliance between mothers and their male offspring may make them vulnerable to female aggression. De Waal has warned of the danger of romanticizing Bonobos: "All animals are competitive by nature and cooperative only under specific circumstances" as well as writing that "When first writing about their behavior, I spoke of 'sex for peace' precisely because bonobos had plenty of conflicts. There would obviously be no need for peacemaking if they lived in perfect harmony". In marked contrast to the Common Chimpanzee there are no confirmed reports of lethal aggression between Bonobos, either in the wild or in captivity. The immature state of Bonobo research in the wild compared to that of the Common Chimpanzee, however, means that lethal aggression may yet be discovered. Primatologist Gottfried Hohmann has observed one incident in the field that he suspects resulted in a fatality.[14]

Sexual social behavior

Sexual intercourse plays a major role in Bonobo society, being used as a greeting, a means of conflict resolution and post-conflict reconciliation, and as favors traded by the females in exchange for food. Bonobos are the only non-human apes to have been observed engaging in all of the following sexual activities: face-to-face genital sex (most frequently female-female, then male-female and male-male), tongue kissing, and oral sex.[15] In scientific literature, the female-female sex is often referred to as GG rubbing or genital-genital rubbing, while male-male sex is sometimes referred to as penis fencing.[16]

Sexual activity happens within the immediate family as well as outside it, and often involves adults and children, even infants.[17] Bonobos do not form permanent relationships with individual partners. They also do not seem to discriminate in their sexual behavior by gender or age, with the possible exception of sexual intercourse between mothers and their adult sons; some observers believe these pairings are taboo. 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 allowing for peaceful feeding.[18]

Bonobo males frequently engage in various forms of male-male genital sex (frot).[19][20][21] One form has two males hang from a tree limb face-to-face while "penis fencing". Frot may also occur where two males rub their penises together while in missionary position. A special form of frot called "rump rubbing" occurs to express reconciliation between two males after a conflict, where they stand back-to-back and rub their scrotal sacs together.

Bonobo females also engage in female-female genital sex (tribadism) to socially bond with each other, thus forming a female nucleus of Bonobo society. The bonding between females allows them to dominate Bonobo society - although male Bonobos are individually stronger, they cannot stand alone against a united group of females. Adolescent females often leave their native community to join another community. Sexual bonding with other females establishes the new females as members of the group. This migration mixes the Bonobo gene pools, providing genetic diversity.

Bonobo reproductive rates are not any higher than that of the Common Chimpanzee. Female Bonobos carry and nurse their young for five years and can give birth every five to six years. Compared with Common Chimpanzees, Bonobo females resume the genital swelling cycle much sooner after giving birth, allowing them to rejoin the sexual activities of their society. Also, Bonobo females who are either sterile or too young to reproduce still engage in sexual activity.

Craig Stanford, an American primatologist, has challenged the claim that Bonobos are more sexually active than Common Chimpanzees. Stanford compared existing data on Common Chimpanzees and Bonobos in the natural habitat and found that female Common Chimpanzees copulated at least as often as female Bonobos, while male chimpanzees actually copulated more than male Bonobos.[22] His comparison excluded same-sex sexual contacts, however, which are very common in Bonobos. De Waal's book on Bonobos includes interviews with field workers and relies on the studies by Takayoshi Kano, the only scientist to have worked for two decades with wild Bonobos. [23] Kano's work supports claims about the Bonobos' pronounced sexual tendencies and their relative peacefulness.

Other social behavior

Females are somewhat smaller than males but can be considered to have a higher social status. Strong female bonding allows groups of female Bonobos to dominate the community. Aggressive encounters between males and females are rare, and males are tolerant of infants and juveniles. The male's status reflects the status of his mother, and the son-mother bond often stays strong and continues throughout life. While social hierarchies do exist, rank does not play as prominent a role as it does in other primate societies.

Bonobos are active from dawn to dusk and live in a fission-fusion pattern: a tribe of about a hundred will split into small groups during the day while looking for food, and then come back together to sleep. They sleep on trees in nests they construct. Unlike Common Chimpanzees, who are known to hunt monkeys, Bonobos are primarily frugivores, although they do eat insects and have been observed occasionally catching small mammals such as squirrels and duikers.


Closeness to humanity

Bonobos are capable of passing the mirror-recognition test for self-awareness. They communicate through primarily vocal means, although the meanings of their vocalizations are not currently known; however, humans do understand their facial expressions[7] and some of their natural hand gestures, such as their invitation to play. Two Bonobos at the Great Ape Trust, Kanzi and Panbanisha, have been taught a vocabulary of over 3,000 words which they can type using a special keyboard of lexigrams (geometric symbols), and they can respond to spoken sentences. Some, such as bioethicist Peter Singer, argue that these results qualify them for the "rights to survival and life," rights that humans theoretically accord to all persons.


Around 10,000 Bonobos are found only south of the Congo River and north of the Kasai River (a tributary of the Congo),[17] in the humid forests of the Democratic Republic of Congo of central Africa. They are an endangered species, due to both habitat loss and hunting for bushmeat, the latter activity having increased dramatically during the current civil war due to the presence of heavily armed militias even in remote "protected" areas such as Salonga National Park. Today, at most several thousand Bonobos remain. This is part of a more general trend of ape extinction.

Conservation efforts

Since the 1990s, war in the Democratic Republic of Congo (DRC) has had a major impact on both the Bonobo and human population. The people of the DRC now, more than ever, have a desire to protect their interests. Bonobos are in danger of being hunted to extinction. The key to Bonobo conservation efforts is balancing these issues.

As the Bonobo's habitat is shared with people, the ultimate success of conservation efforts will rely on local and community involvement. The issue of parks vs. people[24] is very cogent in the Cuvette Centrale, the Bonobo's range. There is strong local and broad-based Congolese resistance to establishing national parks, as indigenous communities have often been driven from their forest homes by the establishment of parks. In Salonga, the only existing national park in the Bonobo habitat, there is no local involvement, and recent surveys indicate that the Bonobo, the African Forest Elephant, and other species have been severely devastated by poachers and the thriving bushmeat trade. In contrast to this, there are areas where the Bonobo and biodiversity still thrive without any established parks, due to the indigenous beliefs and taboos against killing Bonobos.

During the wars in the 1990s, researchers and international non-governmental organizations (NGOs) were driven out of the Bonobo habitat. In 2002, the Bonobo Conservation Initiative initiated the Bonobo Peace Forest Project in cooperation with national institutions, local NGOs and local communities. The Peace Forest Project works with local communities to establish a linked constellation of community-based reserves, managed by local and indigenous people. Although there has been only limited support from international organizations, this model, implemented mainly through DRC organizations and local communities, has helped bring about agreements to protect over Template:Convert/sqmiTemplate:Convert/test/A of the Bonobo habitat. According to Dr. Amy Parish, the Bonobo Peace Forest "…is going to be a model for conservation in the 21st century."[25]

This initiative has been gaining momentum and greater international recognition and has recently gained greater support through Conservation International, the Global Conservation Fund, United States Fish and Wildlife Service's Great Ape Conservation Fund, and the United Nations' Great Apes Survival Project.

In 1995, concern over declining numbers of bonobos in the wild led the Zoological Society of Milwaukee in Milwaukee, Wis., with contributions from bonobo scientists around the world, to publish the Action Plan for Pan paniscus: A Report on Free Ranging Populations and Proposals for their Preservation. The Action Plan compiles population data on bonobos from 20 years of research conducted at various sites throughout the bonobo’s range. The plan identifies priority actions for bonobo conservation and serves as a reference for developing conservation programs for researchers, government officials and donor agencies.

Acting on Action Plan recommendations, the ZSM developed the Bonobo and Congo Biodiversity Initiative (BCBI). This program includes habitat and rain-forest preservation, training for Congolese nationals and conservation institutions, wildlife population assessment and monitoring, and education. The Zoological Society has conducted regional surveys within the range of the bonobo in conjunction with training Congolese researchers in survey methodology and biodiversity monitoring. The Zoological Society’s initial goal was to survey Salonga National Park to determine the conservation status of the bonobo within the park and to provide financial and technical assistance to strengthen park protection. As the project has developed, the Zoological Socity has become more involved in helping the Congolese living in bonobo habitat. The Zoological Society has built schools, hired teachers, provided some medicines, and, as of 2007, started an agriculture project to help the Congolese learn to grow crops and depend less on hunting wild animals.

With grants from the United Nations, USAID, the U.S. Embassy, the World Wildlife Fund and many other groups and individuals, the Zoological Society also has been working to: • survey the bonobo population and its habitat in order to find ways to help protect these apes • develop anti-poaching measures to help save apes, forest elephants and other endangered animals in Congo’s Salonga National Park, a U.N. World Heritage Site • Provide training, literacy education, agricultural techniques, schools, equipment and jobs for Congolese living near bonobo habitats so that they will have a vested interest in protecting the great apes. As of as of 2007, the ZSM started an agriculture project to help the Congolese learn to grow crops and depend less on hunting wild animals. • model small-scale conservation methods that can be used throughout Congo

Starting in 2003, the US government allocated $54 million to the Congo Basin Forest Partnership. This significant investment has triggered the involvement of international NGOs to establish bases in the region and work to develop Bonobo conservation programs. This initiative should improve the likelihood of Bonobo survival, but its success may still depend upon building greater involvement and capability in local and indigenous communities.[26]

The Congo is setting aside more than Template:Convert/sqmiTemplate:Convert/test/A of rain forest to help protect the endangered bonobo,in this Central African country. U.S. agencies, conservation groups and the Congolese government have come together to set aside Template:Convert/sqmiTemplate:Convert/test/A of tropical rain forest, the U.S.-based Bonobo Conservation Initiative. The area amounts to just over 1 percent of vast Congo - but that means a park larger than the state of Massachusetts.

The bonobo population is believed to have declined sharply in the last 30 years, though surveys have been hard to carry out in war-ravaged central Congo. Estimates range from 60,000 to fewer than 5,000 living, according to the World Wildlife Fund.

The Sankuru reserve also contains okapi, closely related to the giraffe, that is also native to Congo, elephants and at least 10 other primate species.

In addition, concerned parties have addressed the crisis on several science and ecological websites. Organizations like the World Wide Fund for Nature, the African Wildlife Foundation, and others are trying to focus attention on the extreme risk to the species. Some have suggested that a reserve be established in a less unstable part of Africa, or on an island in a place like Indonesia. Non-invasive medical research could be conducted on relocated free Bonobos with little risk or discomfort.[How to reference and link to summary or text]

See also


  1. Groves, Colin (16 November 2005). Wilson, D. E., and Reeder, D. M. (eds) Mammal Species of the World, 3rd edition, 183, Johns Hopkins University Press. ISBN 0-801-88221-4.
  2. Template:IUCN2007 Listed as Endangered (EN A4cd v3.1)
  3. Frans de Waal, Frans Lanting (1997) Bonobo: The Forgotten Ape, University of California Press.
  4. Ihobe, H. (1992). "Observations on the meat-eating behavior of wild bonobos (Pan paniscus) at Wamba, Republic of Zaire," Primates, 33(2):247-250
  6. Sue Savage-Rumbaugh & Roger Lewin (1994). Kanzi: the ape at the brink of the human mind, 97, John Wiley & Sons.
  7. 7.0 7.1 Colombus Zoo: Bonobo. URL accessed on 2006-08-01.
  8. Takahata, N.; Satta, Y. & Klein, J. (1995). Divergence time and population size in the lineage leading to modern humans. Theor Popul Biol 48 (2): 198-221.
  9. The Chimpanzee Sequencing and Analysis Consortium (2005). Initial sequence of the chimpanzee genome and comparison with the human genome. Nature 437: 69-87.
  10. Hecht, Jeff (2003-05-19). Chimps are human, gene study implies. New Scientist.
  11. Won, Yong-Jin et al. (2004-10-13). Divergence Population Genetics of Chimpanzees 22 (2): 297-307. DOI:10.1093/molbev/msi017 10.1093/molbev/msi017.
  12. Fischer, Anne et al. (2004-02-12). Evidence for a Complex Demographic History of Chimpanzees. Molecular Biology & Evolution 21 (5): 799-808. DOI:10.1093/molbev/msh083 10.1093/molbev/msh083.
  13. Sussman R. (2004). The Demonic Ape [BBC Horizon programme].
  14. Parker, Ian. (2007-07-30). "Swingers". The New Yorker.
  15. Bonobos at the Columbus Zoo
  16. Frans B. M. de Waal. "Bonobos and Fig Leaves" The ape and the sushi master : cultural reflections by a primatologist, Basic Books.
  17. 17.0 17.1 Dawkins, Richard (2004). "Chimpanzees" The Ancestor's Tale, Houghton Mifflin.
  18. Frans B. M. de Waal (1995). Bonobo Sex and Society. Scientific American. URL accessed on 2006-07-17.
  20. The behavior of a close relative challenges assumptions about male supremacy in human evolution
  21. Courtney Laird, "Social Organization"
  24. Reid, John, Parks and people, not parks vs. people, San Francisco Chronicle, June 15, 2006
  25. "The Make Love, Not War Species," Living on Earth, (July 2006), National Public Radio
  26. Chapin, Mac, (November/December 2004), Vision for a Sustainable World, WORLDWATCH magazine

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