Wild chimpanzees only live in Africa.

Humans and chimpanzees share 95 to 98 percent of the same DNA. Biologically, chimpanzees are more closely related to humans than they are to gorillas.

Chimpanzees and other species, including some types of birds, make and use tools. For a long time, scientists thought human beings were the only ones who made tools.

Chimpanzees use more tools for more purposes than any other creatures except humans.

In captivity, chimpanzees can be taught human languages such as ASL (American Sign Language). A female chimp named Washoe knew more than 240 signs.

Chimpanzees can catch or be infected with human diseases.

Chimpanzees in the wild rarely live longer than 50 years. Captive chimps can live more than 60 years.

Chimpanzees sometimes hunt and eat small mammals such as bushbuck or monkeys.

They also eat fruit, nuts, seeds, blossoms, leaves, and many kinds of insects.

Chimpanzees have a wide variety of tastes and are able to live in a wide variety of habitats, unlike gorillas and orangutans who have narrower diets.

Different chimpanzee groups use tools in different ways. Chimpanzees of the Tai Forest in Cote d'Ivoire crack open nuts with rocks, for example, while the Gombe chimps have never been seen doing this.

One of the chimpanzee calls is the "pant-hoot." Each individual has his or her own distinctive pant-hoot, so that the chimp can be identified with precision.

Chimpanzees laugh when they play.

Chimps groom each other. Grooming helps relations within the community and calms nervous or tense chimps.

When chimpanzees are angry or frightened their hair stands on-end.

Male chimpanzees show their power in "displays." Their hair stands on end so they look bigger, they scream, stamp their feet, and go on a tear, dragging branches, or hurling rocks. This may scare other chimpanzees and keep them from picking a fight.

Mothers and dependent young (up to age seven or so) are always together.

Chimpanzees communicate much like humans do -- by kissing, embracing, patting on the back, touching hands, tickling.

When a mother dies, her orphaned offspring may be unable to survive. But older siblings often adopt their orphaned brothers or sisters, and occasionally infants are adopted by chimps not related to them.

Infant chimpanzees have a white tail tuft that disappears after their childhood.

Chimpanzees walk on all fours and have longer arms than legs. They are called “knuckle walkers” because they use their knuckles for support.

Like humans, chimps have opposable thumbs and opposable big toes which allow them to grip things with their feet.

At Gombe National Park, site of Jane Goodall's research, adult males weigh between 90 and 115 pounds. They are about four feet tall when standing upright. Females are slightly smaller. (Chimpanzees in West Africa and those in captivity may be larger.)

Chimpanzees are not meant to be pets; a full-grown chimpanzee has five or six times the strength of a human being.

Chimpanzees are endangered. There are probably between 172,000 and 300,000 chimpanzees remaining in the wild.

Chimps can be found in about 21 African countries, mostly in central Africa.

Most chimps live in rainforest areas on what used to be the equatorial forest "belt." Sadly, the rain forests in Africa are being cut down, leaving only patches of forest where the belt once stretched continuously.

Another great threat to the continued existence of wild chimpanzees is commercial hunting for meat.

Natural history

Chimpanzees awaken at dawn, and their day is spent both in the trees and on the ground. After a lengthy midday rest, late afternoon is usually the most intensive feeding period. In the trees, where most feeding takes place, chimps use their hands and feet to move about. They also leap and swing by their arms (brachiate) skillfully from branch to branch. Movement over any significant distance usually takes place on the ground. Though able to walk upright, chimpanzees more often move about on all fours, leaning forward on the knuckles of their hands (knuckle walking). At night they usually sleep in the trees in nests they build of branches and leaves. Chimpanzees are unable to swim, but they will wade in water. The chimpanzee diet is primarily vegetarian and consists of more than 300 different items, mostly fruits, berries, leaves, blossoms, and seeds but also bird eggs and chicks, many insects, and occasionally carrion. Chimpanzees also hunt, both alone and in groups, stalking and killing various mammals such as monkeys, duikers, bushbucks, and wild pigs. They also appear to use certain plants medicinally to cure diseases and expel intestinal parasites.

chimpanzee (Pan troglodytes)Chimpanzees (Pan troglodytes) spend their time both on the ground and in the trees. Although they often leap and swing by their arms (brachiate) skillfully from branch to branch among the trees, their movement over any significant distance usually takes place on the ground.© Uryadnikov Sergey/Fotolia

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The female chimpanzee bears a single young at any time of year after a gestation period of about eight months. The newborn weighs about 1.8 kg (about 4 pounds), is almost helpless, and clings to the fur of the mother’s belly as she moves. From about 6 months to 2 years, the youngster rides on the mother’s back. Weaning takes place at about 5 years. Males are considered adults at 16 years of age, and females usually begin to reproduce at about 13 years, but often only two offspring survive during her lifetime. The longevity of chimps is about 45 years in the wild and 58 in captivity; however, older individuals have been documented. For example, Cheetah the chimpanzee, an animal actor from the Tarzan movies of the 1930s and ’40s, was reported to have lived approximately 80 years.

Conservation status

Chimpanzees are an endangered species; their population in the wild has been reduced by hunting (primarily for meat), destruction of habitat from logging or farming, and commercial exportation for use in zoos and research laboratories. The International Union for Conservation of Nature (IUCN) noted that, despite having one of the largest geographic ranges of the great apes, chimpanzee populations have fallen significantly since the 1980s. Lions and leopards also prey upon chimpanzees.

geographic extent of chimpanzees and bonobos (genus Pan)The geographic range of the primate genus Pan—made up of the bonobo (P. paniscus) and the chimpanzee (P. troglodytes)—covers large parts of western and central Africa.Encyclopædia Britannica, Inc./Kenny Chmielewski

Social behaviour

Chimpanzees are lively animals with more extraverted dispositions than either gorillas or orangutans. They are highly social and live in loose and flexible groups known as communities, or unit groups, that are based on associations between adult males within a home range, or territory. Home ranges of forest-dwelling communities can be as small as a few square kilometres, but home ranges covering hundreds of square kilometres are known among savanna communities. A community can number from 20 or fewer to well over 100 members. Each consists of several subgroups of varying size and unstable composition. Social dominance exists, with adult males being dominant over adult females and adolescent males. Within a community, there are twice or three times as many adult females as adult males; the number of adults is about equal to the number of immature individuals. Communities usually divide into subgroups called parties, which vary widely in size. The dominance hierarchy among male chimpanzees is very fluid; individuals associate with each other and join and leave different subgroups with complete freedom. The dominant (alpha) male of a group can monopolize ovulating females through possessive behaviour. On the other hand, gang attack by subordinate males can expel an alpha male. Males spend all of their lives in the community they are born in, but occasionally a juvenile male may transfer to another community with his mother. In contrast to males, most females leave their group of birth to join a neighbouring group when they mature at around age 11. Female chimpanzees spend most of their time with their young or with other females. Those with dependent offspring are more likely to range alone or in small parties within narrow “core areas.” Females have been known to form coalitions against a bullying adult male or newly immigrated female.

adult chimpanzees with offspringMale chimpanzees (Pan troglodytes) spend all of their lives in the community they are born in, but occasionally a juvenile male may transfer to another community with his mother. In contrast to males, most females leave their group of birth to join a neighbouring group when they mature at around age 11.© estima/Fotolia

Relations between different chimp communities tend to be hostile. Intruders on a group’s home range may be attacked, and adult males engage in boundary patrol. On rare occasions, a group may invade a neighbouring territory that is much smaller in size, and fatalities among the smaller group result. Infanticide and cannibalism by adult males, and to a lesser extent by adult females, have been observed. Victimized infants are not only those of neighbouring groups but also those born to newly immigrated females. Between- and within-group competition among individuals of the same sex is the likely cause of such violence. Sometimes a male and female will form a consortship, engaging in exclusive mating relationships by leaving other members of the group and staying in the periphery of the group range. This strategy, however, brings increased risk of attack by neighbouring groups.

Chimpanzees exhibit complex social strategies such as cooperation in combat and the cultivation of coalitions and alliances via ranging together, reciprocal grooming, and the sharing of meat (sometimes in exchange for mating opportunities). An alpha male, for instance, may interfere with his rival in grooming with a third party because such a coalition might jeopardize the alpha’s status. On the other hand, the third party might show strategic opportunism in such a situation, since his assistance to either side could determine which of his superiors prevails. Chimpanzees, therefore, appear to have some concept of “trade.” They console, reconcile, and retaliate during fighting and so share emotions and aspects of psychology similar to those found in humans: self-recognition, curiosity, sympathy, grief, and attribution. Although chimps take care of orphaned infants, they also tease handicapped individuals, conceal information that would bring disadvantage to themselves, and manipulate others for their own advantage by expressing deceptive postures, gestures, and facial expressions.

Chimpanzees are highly intelligent and are able to solve many kinds of problems posed to them by human trainers and experimenters. A number of researchers have taught chimpanzees to use sign language or languages based on the display of tokens or pictorial symbols. The implications of these language studies have been contested, however. Critics charge that apes have not acquired true language in the sense of understanding “words” as abstract symbols that can be combined in meaningful new ways. Other investigators maintain that more recent language training has resulted in the chimpanzees’ acquiring a true recognition of “words” as abstractions that can be applied in novel contexts.

Jane GoodallBritish ethologist Jane Goodall with chimpanzee Freud at Gombe Stream National Park in Tanzania.Michael Neugebauer/the Jane Goodall Institute

Communication between chimps in the wild takes the form of facial expressions, gestures, and a large array of vocalizations, including screams, hoots, grunts, and roars. Males display excitement by standing erect, stamping or swaying, and letting out a chorus of screams. Chimps use louder calls and gestures for long-distance communication (such as drumming on tree buttresses) and quieter calls and facial expressions for short-distance communication. Similarities to human laughter and smiling might be seen in their “play panting” and grinning, respectively.

chimpanzee vocalizationCommunication between chimps in the wild takes the form of facial expressions, gestures, and a large array of vocalizations, including screams, hoots, grunts, and roars.© Uryadnikov Sergey/Fotolia

Various tools are used in several contexts. Chimpanzees “fish” for termites and ants with probes made of grass stalks, vines, branches, peeled bark, and midribs of leaves. They crack hard nuts open by using stones, roots, and wood as hammers or anvils, and they use “leafy sponges” (a handful of folded leaves or moss) to drink water. Branches and leaves are detached and displayed during courtship. In threat displays, chimps throw rocks and drag and throw branches. Sticks are used to inspect dead pythons or other unfamiliar objects that might be dangerous. Leaves are used hygienically in wiping the mouth or other soiled body parts. Chimpanzees also use different tools in succession as a “tool set.” For example, chimpanzees of the Congo basin first dig into termite mounds with a stout stick and then fish for individual termites with a long, slender wand. Tools are also used in combination as “tool composites.” Chimpanzees in the Guinea region push leafy sponges into hollows of trees containing water and then withdraw the wet sponges by using sticks. Chimps thus differ locally in their repertoire of tool use, with younger animals acquiring tool-using behaviours from their elders. Such cultural differences are also seen in food items consumed and in gestural communication. Chimpanzees indeed possess culture when it is defined as the transmission of information from generation to generation via social learning shared by most members of a single age or sex class in a given group.

chimpanzee tool useChimpanzees (Pan troglodytes) “fish” for termites and ants with probes made of grass stalks, vines, branches, peeled bark, and midribs of leaves.© Mark Higgins/Dreamstime.com

Observe chimpanzees' social interactions in their rainforest, grassland, and woodland habitats

Chimpanzees possess a unique culture, and their intelligence, responsiveness, and exuberance have made them ideal nonhuman subjects for study.

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Chimpanzees’ intelligence, responsiveness, and exuberance have made them ideal nonhuman subjects for psychological, medical, and biological experiments. Young chimpanzees can become very attached to their human trainers, and their expressions of feeling resemble those of humans more closely than any other animal.

Taxonomy

Genetic analysis suggests that the lineages leading to modern humans and chimpanzees diverged from each other between 6.5 million and 9.3 million years ago and that at least 98 percent of the human and chimpanzee genomes are identical. Chimpanzees are classified taxonomically as a single species, Pan troglodytes. (The so-called pygmy chimpanzee, or bonobo, is a distinct and separate species, P. paniscus, that diverged from chimpanzees about 1.7 million years ago.) Four subspecies of P. troglodytes are recognized: the tschego, or Central African chimpanzee (P. troglodytes troglodytes), also known as the common chimpanzee in continental Europe; the West African, or masked, chimpanzee (P. troglodytes verus), known as the common chimpanzee in Great Britain; the East African, or long-haired, chimpanzee (P. troglodytes schweinfurthii); and the Nigerian-Cameroon chimpanzee (P. troglodytes ellioti, which was formerly classified as P. troglodytes vellerosus).

human evolutionThe divergence of humans and great apes from a common ancestor.Encyclopædia Britannica, Inc.