Bonobo (Pan paniscus): Facts, Behavior and Habitat

What does a bonobo look like?

Bonobos are covered in black hair, but the face, hands and feet are bare and dark. Unlike chimpanzees, which are often pale-faced when young, bonobos have black faces from birth, with strikingly pink lips. Their head hair is long and often looks neatly parted down the middle, and the hair on the cheeks forms side whiskers. Young bonobos and many adults keep a white tuft of hair on the rump.

Compared with the chimpanzee, a bonobo has a smaller, rounder head with less prominent brow ridges, small ears, a slimmer upper body, narrow shoulders, a thin neck and relatively long legs. These proportions give bonobos a more upright posture when they stand or walk on two legs, which they do more often than chimpanzees, especially when carrying food. Most of the time, though, they move on all fours by knuckle-walking. Like all apes, they have no tail.

How big is a bonobo?

Bonobos were long called “pygmy chimpanzees,” but the name is misleading: the two species overlap broadly in size. Wild male bonobos weigh about 37–61 kg (82–134 lb), averaging about 45 kg (99 lb), and females 27–38 kg (60–84 lb), averaging about 33 kg (73 lb). Head-and-body length is 70–83 cm (28–33 in), and standing upright, males average about 1.19 m (3.9 ft) and females about 1.11 m (3.6 ft).

Males are only about a third heavier than females, a smaller size difference between the sexes than in chimpanzees or gorillas.

Where do bonobos live?

Bonobos live only in the Democratic Republic of the Congo (DR Congo), in the vast lowland forests of the Congo Basin. Their range lies south of the great arc of the Congo River and north of the Kasai River, covering roughly 500,000 km² (190,000 sq mi), although bonobos are patchily spread within it. Chimpanzees live north of the river, and because neither ape can swim, the river keeps the two species apart.

Bonobos live mainly in moist lowland rainforest, but also use seasonally flooded swamp forest, old secondary forest that has regrown on abandoned farmland, and, in the south of their range, a mosaic of forest and grassland. Much of what we know comes from a handful of long-term research sites such as Wamba, Lomako, LuiKotale and Kokolopori. More on their range in Where do bonobos live?

What do bonobos eat?

Bonobos are omnivores, but fruit makes up most of their diet, and they spend much of the day traveling between fruiting trees. They also eat leaves, young shoots, flowers, seeds, bark, pith, mushrooms and honey. An important part of their diet is the soft, protein-rich stems and leaves of herbs that grow on the forest floor and in swampy clearings.

Animal food is a small but regular extra. Bonobos eat insects, such as termites and caterpillars, and catch small mammals, including duikers (small forest antelopes), flying squirrels and other rodents. At some sites they have been seen hunting and eating monkeys, and females sometimes control and share the meat. Bonobos are generous with food: unlike most animals, they often share food voluntarily, even with bonobos they do not know.

Social life: a female-centered society

Bonobos live in communities of a few dozen to more than 100 individuals that split into smaller foraging parties during the day and often gather again to build sleeping nests in the trees at night. This flexible pattern is called fission-fusion.

The most unusual feature of bonobo society is the power of females. Young females leave their birth community and join a new one, so the adult females in a group are usually not related. Even so, they form close bonds and alliances. Together, females can dominate males, control access to prized food and protect each other from harassment. Most communities are led by a coalition of older females, with some high-ranking males.

Males stay in the community where they were born, and a male’s rank depends heavily on his mother. Mothers support their adult sons in conflicts and even help them gain access to females. Bonobos also use sexual contact, between and within the sexes, to ease tension, reconcile after quarrels and greet one another.

Are bonobos peaceful?

Bonobos are much less violent than chimpanzees. A large 2014 study combining decades of field data recorded more than 150 killings by chimpanzees but only one suspected killing by bonobos, and meetings between neighboring bonobo communities are often relaxed, with grooming, play and shared meals. Bonobos are not territorial in the way chimpanzees are.

That does not make them gentle hippies. Bonobos argue, chase and bite, and a 2024 study found that bonobo males actually got into aggressive incidents more often than chimpanzee males, although bonobo aggression was mostly within the group and far less often lethal. See Why are bonobos called the peaceful ape?

Communication and intelligence

Bonobos communicate with a wide range of calls, facial expressions, gestures and touch. Their voices are higher-pitched than chimpanzees’, and they make soft peeps and high hoots that keep group members in contact. They also use many gestures, a large number of which they share with chimpanzees.

Bonobos are highly intelligent. They recognize themselves in mirrors, solve problems and learn from each other. Wild bonobos use tools less than chimpanzees, using leaves as rain covers or sponges and branches for display, but captive bonobos can learn complex tool tasks. The bonobo Kanzi, raised in a research center in the United States, learned to understand many spoken English words and to communicate by touching hundreds of symbols called lexigrams.

Reproduction and lifespan

Bonobos breed throughout the year. After a pregnancy of about eight months (around 230–240 days), a female gives birth to a single infant, which clings to her belly and later rides on her back. Infants are nursed for about four years, and a mother has a baby only about every four to five years. Females usually give birth for the first time at around 13–15 years old.

The long childhood means bonobo populations grow very slowly and recover poorly from losses. Lifespan in the wild is not well known, but some individuals at long-term study sites were estimated to have lived 40–50 years. In captivity, bonobos commonly live around 40 years.

Discovery, name and predators

Bonobos were not recognized by science until the 20th century. In 1929, the German anatomist Ernst Schwarz described them from a skull in a museum in Belgium that had been labeled as a young chimpanzee, at first treating them as a chimpanzee subspecies. In 1933, the American anatomist Harold Coolidge raised the bonobo to a full species. The origin of the name “bonobo” is uncertain; one popular explanation is that it comes from a misspelling of Bolobo, a town on the Congo River.

Wild bonobos have few natural predators. Leopards are the main threat, and large pythons and crowned eagles may take young bonobos. Males and females give alarm calls and may mob a threat together. Because bonobos are shy and live in remote forest, there are few direct observations of predation.

Threats and conservation status

The bonobo is listed as Endangered on the IUCN Red List, and its population is thought to be decreasing. Because so much of its forest is remote, estimates vary widely, from a minimum of about 15,000–20,000 to around 50,000.

The main threat is hunting for bushmeat, which increased sharply during the wars in DR Congo in the 1990s and 2000s, when armed groups moved through the forest. Habitat loss from logging, farming and growing human settlements is another threat, along with diseases that can pass between people and apes. Infants are sometimes taken alive when their mothers are killed and sold illegally as pets.

Bonobos are protected in Salonga National Park, one of Africa’s largest rainforest parks, in Lomami National Park, and in community reserves where local people help protect the forest. In some areas, traditional taboos against eating bonobos have also helped them survive. Orphaned bonobos are cared for at the Lola ya Bonobo sanctuary near Kinshasa, and some have been returned to the wild.

Bonobos and humans

Bonobos and chimpanzees are humanity’s closest living relatives. Our lineages split from theirs roughly 6–8 million years ago, while bonobos and chimpanzees separated from each other much later, somewhere around 1–2 million years ago by many estimates, and under a million years by some genetic studies. That means humans are equally related to both, sharing about 98.7 percent of DNA with each (see How much DNA do we share with chimpanzees?). Studying how two such closely related apes came to have such different societies helps scientists think about the roots of human cooperation and conflict. For a side-by-side look at the two apes, see chimpanzee vs bonobo.