Mammals
Bonobo
Pan paniscus · also called pygmy chimpanzee, dwarf chimpanzee
The bonobo is the ape people know least and are most closely related to — one of our two nearest living relatives, alongside the chimpanzee, and the one whose society looks least like the popular idea of “ape.” Bonobo groups are run by coalitions of females, rarely turn violent, and use affection and sex where chimpanzees would use force.
Overview
Bonobos live in lowland rainforest and seasonally flooded swamp forest in the central Congo Basin, entirely south of the Congo River and entirely within the Democratic Republic of the Congo. They are the only great ape found in just one country. They move through the trees and on the ground, feed heavily on ripe fruit, and live in fission-fusion communities of a few dozen animals that split into smaller parties by day and regroup to nest at night.
A female-centred society
Although males are somewhat larger, female bonobos collectively outrank them. Unrelated females form strong, lasting alliances — reinforced by grooming and by frequent brief sexual contact — and act together against any male that becomes aggressive. A male’s social position depends largely on his mother’s rank, and mothers stay closely involved in their sons’ lives into adulthood. The result is a community with low aggression: bonobos have never been recorded killing each other, and inter-group meetings that would trigger deadly violence in chimpanzees often end in mingling and feeding together.
Sex as social glue
Bonobos use sexual behaviour for far more than reproduction — to greet, to reduce tension around food, and to reconcile after conflict, across all combinations of age and sex. This is the trait that made them famous, and while it is only one part of their lives, it genuinely underpins the female bonding that keeps their society peaceful.
Intelligence
Bonobos make and use tools readily in captivity, understand symbols and spoken words in language studies, cooperate on tasks, and show strong social awareness and apparent empathy. In the wild they use tools less than chimpanzees, for reasons that are still debated.
Status
The bonobo is Endangered, with a wild population estimated between 10,000 and 50,000 and falling. Bushmeat hunting and forest loss are the main threats, made harder to counter by the region’s instability. Their slow breeding — one infant about every five years — leaves little room for recovery. Community-run reserves offer the most promising path forward.
Bonobo: common questions
What is the difference between a bonobo and a chimpanzee?
They are separate species, split by the Congo River, which bonobos live south of and chimpanzees north of. Physically, bonobos are more slender with longer legs, a rounder head, a flatter face, dark faces from birth, and hair that parts in the middle. Behaviourally the contrast is sharper. Chimpanzee groups are male-dominated, territorial, and can be lethally violent between communities, while bonobo groups are female-centred, far less aggressive, and have never been observed to kill one another. Bonobos also hunt less and use tools less in the wild, though they match chimps on tool tests in captivity.
Why are bonobos famous for sex?
Bonobos use sexual behaviour as a social tool, separate from reproduction. Brief genital contact — between males and females, females and females, adults and juveniles — is used to greet, to calm a tense situation, to reconcile after a squabble, and to smooth access to food. Because females bond strongly with each other through this, they can collectively dominate larger males and keep aggression low. It is not constant or the whole of bonobo life, but it is a genuine and unusual feature of their society, and it is why researchers sometimes summarise the contrast with chimps as "make love, not war."
How closely related to humans are bonobos?
Bonobos and chimpanzees are equally our closest living relatives, each sharing roughly 98.7% of their DNA with humans — we are more closely related to them than an African elephant is to an Asian elephant. The human lineage split from the common ancestor of bonobos and chimps around 6 to 7 million years ago; bonobos and chimps then split from each other roughly 1 to 2 million years ago, probably when the Congo River formed and divided their ancestor's range.
Why are bonobos endangered?
Bonobos live in only one country, the Democratic Republic of the Congo, in a remote region that has been affected by prolonged conflict and instability. The main threats are hunting for bushmeat (commercial and for the pet trade) and loss of forest to logging, agriculture, and roads. Their slow reproduction — females have a single infant roughly every five years — means populations recover very slowly. Conservation is difficult because of the security situation, but community-managed reserves such as the Bonobo Peace Forest have had success.