Chimpanzee and Bonobo

Western chimpanzee at Tacugama, Sierra Leone. Credit: Frands Carls

Where do chimpanzees and bonobos come from? West- and Equatorial Africa
How big are they? Chimpanzees are around 1m tall; males weigh 50kg and females weigh 35kg (on average)
How old can they get? 30 – 40 years in the wild (50-60 years in captivity)
How do they live? Chimpanzees live in large, multi-male-multi-female groups; For common chimpanzees (Pan troglodytes) males are dominant over all females; for bonobos (Pan paniscus) females occupy high ranking places
Are chimpanzees threatened?
Common chimpanzee: Endangered, population trend: decreasing, wild population size estimates: between 172.000 and 301.000,
Bonobo: Endangered, population trend: decreasing, wild population size estimates: between 5000 – 50.000 individuals

There are two different species of chimpanzees: common chimpanzees (Pan troglodytes) and bonobos (Pan paniscus).  The common chimpanzee is often described as the robust chimpanzee as opposed to the bonobo, or gracile chimpanzee. Typically bonobos have a dark face with pink lips.

Chimpanzees are centred in tropical rainforest (primary and secondary) and also live in forest edges and swamp forest. Chimpanzees appear to survive quite well in lightly logged forest and bush farmland, which makes them less sensitive to moderate ecosystem disturbance but also increasingly vulnerable to humans as many populations exist outside protected areas.

Bonobo at Planckendael, Belgium. (Credit: Tomasz Rusek)

Wild chimpanzees live in multi-male-multi-female fission-fusion communities. This means they live in stable communities, which count about 40-60 individuals. Chimpanzees are both arboreal and terrestrial. They spend most of their days foraging and feeding. They mainly feed on fruits and leaves and only occasionally they also feed on animal prey, including insects. They most often build nests in trees for sleeping.

Populations of wild chimpanzees have declined by more than 66% in the last 30 years. The vulnerability of the chimpanzee is further increased by a slow reproduction rate, which makes it difficult for chimpanzee populations to recover. The reasons for the decline are well known, but there is little hope that the trend downwards will change in the near future. Chimpanzees are threatened by several factors that interlink and impact on each other:

• Intensive deforestation through logging and other extracting industries (oil and mining) disrupts the forest ecosystem.
• Disrupted forest habitat opened up to the effects of wind and sun is more vulnerable to fires.
• The increased access to logged areas opens up for bushmeat hunting and invasion of farmers (which again leads to further fragmentation of the forest and increased hunting pressure).
• Habitat disruption leads to increased contact with humans and poses an additional threat as great ape populations become more vulnerable to infection with human diseases.  Also, zoonoses (diseases that can be transmitted between animals and humans), like Ebola, pose a threat to great ape populations.
• Several populations are also threatened from the effects of armed conflicts resulting in habitat destruction and increased hunting pressure.

More to read

• Primate specialist group
• International Primatological Society
• Great Apes Survival Partnership (GRASP)
• Pan African Sanctuary Alliance (PASA)

Word versions of these fact sheets are available to campaign participants under Resources -> Education. Links to additional sources of information can also be found under Resources.