chimpanzee

Highly intelligent African ape Pan troglodytes that lives mainly in rainforests but sometimes in wooded savannah. Chimpanzees are covered in thin but long black body hair, except for the face, hands, and feet, which may have pink or black skin. They normally walk on all fours, supporting the front of the body on the knuckles of the fingers, but can stand or walk upright for a short distance. They can grow to 1.4 m/4.5 ft tall, and weigh up to 50 kg/110 lb. They are strong and climb well, but spend time on the ground, living in loose social groups. The bulk of the diet is fruit, with some leaves, insects, and occasional meat. Females reach sexual maturity at 8–12 years of age, males at 17–18. Chimpanzees give birth to a single infant approximately every five years. Chimpanzees can use ‘tools’, fashioning twigs to extract termites from their nests. According to a 1998 estimate by the Worldwide Fund for Nature, the world population of chimpanzees stands at 200,000.

Chimpanzees are found in an area from West Africa to western Uganda and Tanzania in the east. There are four subspecies of common chimpanzee. The bonobo or pygmy chimpanzee, Pan paniscus is found only in a small area of rainforest in the Democratic Republic of Congo (formerly Zaire). Bonobos are a distinct species about the same height as ‘common’ chimpanzees, but they are of a slighter build, with less hair, and stand upright more frequently. In 1999 there were believed to be fewer than 15,000 bonobos left and these were threatened by the civil war in the Democratic Republic of Congo.

Studies of chromosomes suggest that chimpanzees are the closest apes to humans, perhaps sharing 99% of the same genes. Trained chimpanzees can learn to communicate with humans with the aid of machines or sign language, but are probably precluded from human speech by the position of the voicebox.

In 1999 British researchers revealed that chimpanzees exhibit diverse cultural behaviour in different study populations, showing that behaviour is learned and passed on in chimpanzee societies. The researchers identified 39 separate behaviours, including differences in feeding techniques, courtship rituals, and domination displays.