Where Do Bonobos Live? Life South of the Congo River

A range shaped by rivers

The bonobo has one of the most clearly defined ranges of any ape. The Congo River sweeps north and then west across central Africa in a huge arc, and bonobos live inside the southern part of that bend. To the north and west lies the Congo River itself, to the east its upper course, the Lualaba, and to the south the Kasai River and its tributaries.

Altogether, this area covers roughly 500,000 km² (190,000 sq mi), about the size of Spain. Bonobos are not spread evenly across it. Surveys have found them clumped in some areas and absent from others, often where hunting pressure is high or where people have lived for a long time.

How the Congo River split bonobos from chimpanzees

The chimpanzee lives north and east of the Congo River, across a wide belt of Africa from Senegal to Tanzania. Bonobos live only to the south. Neither ape swims, so the river is a barrier they cannot cross.

Most scientists think this barrier explains why there are two species. The ancestors of bonobos and chimpanzees were probably separated somewhere around 1–2 million years ago, perhaps when a population crossed during a period of low water or along routes that no longer exist and was then cut off. Isolated on the south bank, it evolved into the bonobo. Genetic studies show that a little interbreeding still happened between the two lineages in the past few hundred thousand years, but today the two species never meet in the wild. See chimpanzee vs bonobo for how different they became.

What kind of habitat do bonobos live in?

Most bonobos live in the moist lowland rainforest of the central Congo Basin, sometimes called the Cuvette Centrale. This is a flat, low-lying region of tall forest crossed by many rivers. Bonobos use several kinds of forest within it:

• Dry-ground rainforest, with tall fruiting trees that provide most of their food.
• Swamp forest, which floods seasonally and offers herbs and aquatic plants.
• Old secondary forest, which has regrown on abandoned farmland.
• Forest-savanna mosaics in the south of the range, where patches of forest alternate with grassland.

Bonobos sleep in nests they build each night high in the trees and feed both in the canopy and on the forest floor. The steady supply of fruit and ground herbs in their forests may help them travel in larger, more stable groups than chimpanzees.

How many bonobos are left?

No one knows exactly how many bonobos there are. Much of their range is remote, roadless and was affected by war for years, so surveys cover only part of it. The IUCN uses a minimum estimate of about 15,000–20,000 individuals, and other estimates reach around 50,000. The species is listed as Endangered, and numbers are thought to be falling, mainly because of hunting for bushmeat and habitat loss.

Who else lives in the bonobo’s forests?

Bonobos share their forests with a rich community of wildlife found only in central Africa. Salonga and the surrounding forests are home to African forest elephants, the okapi in parts of the region, the Congo peafowl, several monkeys such as red-tailed monkeys and black mangabeys, and predators such as leopards. Notably absent are gorillas and chimpanzees, which live only north and east of the river. Without other great apes to compete with, bonobos have the forest-floor herbs to themselves.

Protected areas and research sites

Several places are especially important for bonobos:

• Salonga National Park, a UNESCO World Heritage Site and one of the largest tropical rainforest parks in Africa, covering more than 33,000 km² (12,700 sq mi).
• Lomami National Park, created in 2016 in the east of the bonobo’s range.
• Community reserves such as the Kokolopori Bonobo Reserve and the Luo Scientific Reserve at Wamba, where local people help protect the forest.

Long-term research sites, including Wamba (studied by Japanese scientists since the 1970s), Lomako and LuiKotale, have provided much of what we know about wild bonobos. In some villages, traditional beliefs that forbid eating bonobos have helped them survive close to people.

Where can you see bonobos?

Seeing wild bonobos requires a difficult trip to remote parts of DR Congo, usually through a research or community project. Closer to the capital, the Lola ya Bonobo sanctuary near Kinshasa cares for orphaned bonobos rescued from the bushmeat and pet trade, and some of its bonobos have been released back into protected forest.

Outside Africa, bonobos can be seen in a limited number of zoos in Europe and North America, which run coordinated breeding programs. These captive groups have also taught researchers a great deal about bonobo social life, which is explored in Why are bonobos called the peaceful ape?