Chimpanzee (Pan troglodytes): Facts, Intelligence and Diet

What does a chimpanzee look like?

Chimpanzees have coarse black hair over most of the body, but the face, ears, fingers, palms and soles of the feet are bare. Young chimpanzees have pale, pinkish faces that usually darken with age, and older animals often turn gray around the chin and back and develop bald patches on the forehead.

The body is built for both climbing and walking. The arms are longer than the legs, and an adult’s arm span is roughly one and a half times its standing height. The hands have long fingers and a short thumb, and the big toe is opposable, so the feet can grip branches almost like hands. Like gorillas and bonobos, chimpanzees walk on all fours using the knuckles of their hands, a gait called knuckle-walking. They can also walk upright on two legs for short distances.

The head has a heavy brow ridge, a protruding muzzle, large ears and a mobile upper lip. Adult males have much longer canine teeth than females. There is no tail at all, which is one of the clearest signs that chimpanzees are apes rather than monkeys (see Are chimpanzees monkeys?).

How big is a chimpanzee?

Wild adult males weigh about 34–70 kg (75–154 lb) and females 26–50 kg (57–110 lb). Head-and-body length is 64–93 cm (25–36 in), and a chimpanzee standing upright is about 1–1.7 m (3.3–5.6 ft) tall. Chimpanzees in zoos and laboratories are often heavier than wild ones, and a few exceptional captive males have weighed far more than the normal range.

Size varies between populations. Eastern chimpanzees in East Africa tend to be lighter than chimpanzees in Central Africa. Chimpanzees are heavier and stockier than bonobos on average and much smaller than gorillas, which can weigh three or four times as much.

Where do chimpanzees live?

Chimpanzees live in a broad band across equatorial Africa, from Senegal, Guinea and Sierra Leone in the west, through Nigeria, Cameroon, Gabon and the Republic of the Congo, to the Democratic Republic of the Congo, Uganda, Rwanda and western Tanzania in the east. They live north of the Congo River; the bonobo, their sister species, lives only south of it.

Most chimpanzees live in lowland and mountain rainforest, but they are surprisingly adaptable. Some communities live in swamp forest, others in dry woodland and wooded savanna, such as the hot, open country of Fongoli in Senegal, where chimpanzees rest in caves and pools during the hottest hours. They need trees for food and for building their night nests.

Four subspecies are widely recognized: the western chimpanzee (P. t. verus), the Nigeria-Cameroon chimpanzee (P. t. ellioti), the central chimpanzee (P. t. troglodytes) and the eastern chimpanzee (P. t. schweinfurthii). The central and eastern subspecies are the most numerous; the western chimpanzee is listed separately as Critically Endangered.

What do chimpanzees eat?

Chimpanzees are omnivores, but fruit is the center of their diet. At long-studied sites they spend roughly half to two thirds of their feeding time eating fruit, especially ripe figs. They add young leaves, flowers, seeds, pith, bark, resin, honey and insects such as termites, ants and bee larvae.

Meat is a small but valued part of the diet. Groups of chimpanzees, mainly males, hunt monkeys, with the red colobus the most common prey at several sites, as well as young bushpigs, small antelopes such as duikers, and galagos. The meat is often shared with allies and with females. For more detail, see What do chimpanzees eat?

Tool use and intelligence

Nearly every studied chimpanzee population uses tools. In 1960, Jane Goodall saw a Gombe male she named David Greybeard poke a grass stem into a termite mound to fish out termites, one of the first reports of a wild animal making and using tools. Since then researchers have recorded sticks used to dip for ants and honey, chewed leaves used as sponges to soak up water, and stones and wooden clubs used as hammers to crack hard nuts on anvils.

Different communities have different tool kits, and young chimpanzees learn these skills slowly by watching their mothers over several years. Because these habits differ between groups living in similar habitats, many scientists describe them as cultural traditions. The full story is in Do chimpanzees use tools?

Chimpanzees also recognize themselves in mirrors, remember where and when hundreds of trees will bear fruit, and in experiments can learn symbols and numbers. They are regularly ranked among the smartest animals.

Social life and communication

Chimpanzees live in communities of about 20 to more than 150 members that share a home range, which males patrol and defend. The community rarely gathers in one place. Instead, members travel in small, changing parties that split and merge through the day, a system called a fission-fusion society.

Males stay in the community where they were born and form a clear dominance hierarchy. A male rises in rank through displays, alliances and grooming as much as through fighting, and the top, or alpha, male often relies on the support of allies. Most females move to a neighboring community when they reach adolescence. Grooming, picking through each other’s hair, is the main way chimpanzees build and repair relationships.

Relations between neighboring communities can be hostile. Groups of males sometimes raid neighbors’ territory and may kill members of other communities, behavior first documented at Gombe in the 1970s and since recorded at several sites.

Chimpanzees communicate with a rich mix of calls, gestures, facial expressions and touch. The best-known call is the pant-hoot, a series of hoots that builds to a loud climax and can carry far through the forest. Males also drum on the buttress roots of large trees with their hands and feet, and play faces and panting “laughter” are common in young animals.

Reproduction, life cycle and lifespan

Chimpanzees can breed at any time of year. A receptive female develops a large pink swelling of the skin around her genitals and usually mates with several males of her community, although a male sometimes leads a female away on a private “consortship.”

Pregnancy lasts about eight months, and a single baby is born weighing around 1.5–2 kg (3.3–4.4 lb). The infant clings to its mother’s belly at first and later rides on her back. Young chimpanzees nurse for about four to five years and stay close to their mothers for several more, so females in the wild usually give birth only every five to six years. Females have their first baby at around 13–15 years of age.

This slow life history means that a female may raise only a handful of offspring in her whole life, one reason chimpanzee populations recover very slowly from losses.

Average life expectancy at birth in the wild ranges from about 13 to 33 years depending on the site, because many chimpanzees die as infants or young adults. Chimpanzees that survive to adulthood often live into their 30s or 40s, and a few wild individuals have reached their 50s. In zoos and sanctuaries chimpanzees can live past 60. See How long do chimpanzees live? for the details.

Predators and threats

Leopards are the main natural predator of chimpanzees in many forests, and lions are thought to have killed several chimpanzees in Mahale Mountains National Park in Tanzania. Chimpanzees respond to big cats with loud calls, branch shaking and sometimes by mobbing them.

The serious threats today come from people. Forests are cleared for farming, logging, mining and roads, and roads also give hunters access to remote areas. Chimpanzees are killed for bushmeat, infants are captured for the illegal pet trade (usually after their mothers are killed), and many chimpanzees lose hands or feet in snares set for other animals. Because they are so closely related to us, chimpanzees also catch human diseases: respiratory infections, Ebola and other outbreaks have killed large numbers in some regions.

Conservation status

The IUCN Red List classifies the chimpanzee as Endangered, with a decreasing population. Estimates put the wild population at roughly 170,000–300,000, down from perhaps a million a century ago. The western chimpanzee subspecies is Critically Endangered after its numbers fell sharply in recent decades.

Chimpanzees are legally protected in all the countries where they live and are listed in Appendix I of CITES, which bans commercial international trade. Protected areas, anti-poaching patrols, health rules for tourists and researchers, and sanctuaries for orphans all play a part in their conservation.

Myths and facts

Myth: Humans evolved from chimpanzees. Humans did not descend from chimpanzees. Both species share a common ancestor that lived roughly 6–8 million years ago, and chimpanzees have been evolving along their own path ever since.

Myth: Chimpanzees are five to eight times stronger than people. Early tests produced wildly exaggerated figures. A 2017 study found that chimpanzee muscle produces about 1.35 times the force and power of human muscle of the same size; see How strong is a chimpanzee?

Fact: Chimpanzees and bonobos are equally close to us. The two Pan species split from each other long after their ancestors split from ours, so humans are equally related to both.

Chimpanzees and people

Chimpanzees have shaped our understanding of our own species. Long-term field studies at Gombe and Mahale in Tanzania, Taï in Côte d’Ivoire, Bossou in Guinea and Kibale in Uganda have run for decades, and Jane Goodall’s work at Gombe, begun in 1960, is the longest continuous study of any wild animal. In the past, chimpanzees were widely used in medical research and entertainment. Invasive research on them has now ended in Europe and in United States government-funded work, and many former laboratory chimpanzees live in sanctuaries.

Adult chimpanzees are far stronger and less predictable than they look, and they are not suitable as pets. In the wild, attacks on people are rare and mostly occur where chimpanzees live close to villages and farms.