status: Endangered, IUCN Endangered, ESA
range: Burundi, Cameroon, Central African Republic, Congo, Congo Republic, Côte d'Ivoire, Equatorial Guinea, Gabon, Gambia, Ghana, Guinea, Guinea-Bissau, Liberia, Mali, Nigeria, Rwanda, Senegal, Sierra Leone, Sudan, Tanzania, Uganda
Description and biology
Chimpanzees, gorillas, and orangutans are all considered great apes. Of the three, chimpanzees are the most closely related to humans. Chimpanzees and humans share 98 percent of the same genetic makeup. In addition, the two groups share many social and psychological traits. Researchers have documented chimpanzees making and using tools, expressing complex emotions, forming bonds and friendships, and communicating using sign language.
An average chimpanzee stands 5 feet (1.5 meters) tall and weighs about 150 pounds (68 kilograms). Since its arms are longer than its legs, a chimpanzee walks on the ground using the soles of its feet and the knuckles of its hands. Most of its body is covered with long, black hair. A chimpanzee's hair-less
face can range in color from almost white to almost black. The hair around a chimpanzee's face grays with age, and older chimpanzees often become bald.
Highly social mammals, chimpanzees live in communities made up of 30 to 60 members. During the day, the animals often travel on the ground. At night, they stay in nests they build in treetops. A chimpanzee's diet consists mainly of fruit, but they also eat insects, leaves, flowers, bark, seeds, tree resin, eggs, and meat. At times, chimpanzees band together to hunt animals such as antelopes and monkeys.
Mating between male and female chimpanzees takes place anytime during the year. Unlike many other animal species, female chimpanzees do not have to mate with the dominant male in their group. Instead, females often mate with males of their choosing. After a gestation (pregnancy) period of 230 to 240 days, a female chimpanzee gives birth to a single infant. During the course of her life, an average female chimpanzee will give birth to fewer than five infants. Bonds between mothers and infants are very strong, and some last a lifetime.
Habitat and current distribution
A few centuries ago, several million chimpanzees existed in the equatorial regions of Africa. They inhabited a range of ecosystems, from dense forests to open savannas. Now, estimates vary, but it is thought that there are between 200,000 and 225,000 chimpanzees in the wild, and many believe these estimates are high. Only 10 present-day African nations have chimpanzee populations above 1,000.
About 5,000 chimpanzees exist in captivity worldwide. Over one-half of these are used as subjects in medical research. The rest are zoo exhibits, entertainment props, and private pets.
History and conservation measures
Habitat destruction, disease, and expanding human populations have led to the decline in the number of chimpanzees. Mining has destroyed the chimpanzee habitat in the diamond districts of Sierra Leone and the iron districts of Liberia. The cutting of forests for timber has destroyed the animals' habitat in Uganda. And the conversion of forests into agricultural land has threatened chimpanzees in Rwanda and Burundi.
Certain laws prohibit the hunting and sale of chimpanzees, but these laws are not enforced. Many chimpanzees are caught and traded illegally. For each chimpanzee shipped overseas, ten die during transport due to mistreatment and malnutrition. Two sanctuaries exist in Gambia and Zambia for orphaned chimpanzees and those seized from illegal traders. Most African nations have passed laws and have set aside areas to protect chimpanzees. However, as human populations in Africa continue to grow, many of these reserves may be used to fill human needs.
In 2003, a group of scientists and conservationists called for an upgrade in the status of chimpanzees from endangered to critically endangered. Data coming from Gabon and the Republic of Congo, where most of the world's chimpanzees live, reveals that the ape population there has decreased by half between 1983 and 2000. The reasons for the decline were continued hunting and outbreaks among chimpanzees and gorillas of the Ebola virus, a very deadly and contagious virus that was discovered in Africa during the 1970s and afflicts humans as well. The group of scientists warned that chimpanzees and gorillas are in greater jeopardy of extinction than had been formerly realized. They called for greater enforcement of laws against hunting and capturing chimpanzees and an increased focus on research of the Ebola virus in primates.
chimpanzee, an ape, genus Pan, of the equatorial forests of central and W Africa. The common chimpanzee, Pan troglodytes, lives N of the Congo River. Full-grown animals of this species are up to 5 ft (1.5 m) tall and weigh about 150 lb (68 kg); they have an arm spread of up to 9 ft (2.7 m) and are much stronger than humans. They are covered with long, black hair over most of the body and have naked faces ranging in color from nearly white to nearly black. The pygmy chimpanzee, P. paniscus, now usually called the bonobo, lives south of the Congo. It is a bit smaller and more slenderly built, with a black face.
Chimpanzees spend much time on the ground, where they walk on all fours, using the soles of the feet and the knuckles of the hands; they can also stand on two legs and sometimes walk this way for short distances. They climb trees in pursuit of food and for nesting and can swing by their hands from branch to branch. Their diet consists largely of fruit and other plant matter, but they also hunt and eat small animals, including monkeys. They use and even make primitive tools; for example, they collect termites using twigs and crack nuts using stones. Many primatologists now attribute culture to chimpanzees, noting learned variations in such skills and habits among different groups.
Chimpanzees move about the forest in bands of varying composition, usually numbering six to ten individuals. The males of a group engage in dominance contests involving much screaming and stamping. Family groups consist of mothers and offspring; females mate with many males during their fertile periods. A single infant is born every three to eight years; young chimpanzees ride about on their mothers' backs. Under ideal circumstances chimpanzees may live 50 years.
Although incapable of speech beyond their own simple vocalizations, captive chimpanzees have been taught to communicate in a language using visual rather than verbal symbols. Because of their close evolutionary relationship to humans they are often used for medical and behavioral experimentation, but the degree to which chimpanzees and humans are genetically close is a subject of dispute, with estimates of the amount of DNA the species share ranging from 94.6% to 99.4%. Chimpanzees, especially bonobos, are considered endangered species because of hunting and loss of habitat.
Chimpanzees are classified in the phylum Chordata, subphylum Vertebrata, class Mammalia, order Primates, family Pongidae.
See G. H. Bourne, The Chimpanzee (6 vol., 1973); J. Goodall, In the Shadow of Man (1967) and The Chimpanzees of Gombe (1986); F. de Waal, Bonobo: The Forgotten Ape (1998).
chim·pan·zee / ˌchimˌpanˈzē; -pənˈzē; -ˈpanzē/ • n. a great ape (genus Pan) with large ears, mainly black coloration, and lighter skin on the face, native to the forests of western and central Africa.