Chimpanzees (Pan troglodytes) share over 98% of their genetic material with humans. Behavioural research, both in Africa and in zoos, has given us a lot more information about the behaviour, the way of life and the social and intellectual capabilities of chimpanzees. Chimpanzees are found in various regions of tropical Africa. They live in a variety of habitats, ranging from humid forests to dry savannah woodlands, in communities of between 20 and 100 individuals with changing subgroups. Chimpanzees eat mainly fruit, but they also make and use tools to crack nuts and fish for ants and termites with sticks and specially prepared twigs. Some plant foods seem to be chewed or eaten for medicinal purposes. Meat is also a natural part of the chimpanzees' diet and adult males regularly hunt and catch other animals (baboons, colobus monkeys, bushpigs). This always creates a lot of excitement and leads to much begging for meat and some sharing (although there is some discussion about why the males are willing to share). Sometimes, males may kill and eat infants from females they encounter from another group (more on infanticide by males in general [pdf]) and adult females occasionally steal infants from other mothers to eat.
Chimpanzees become sexually mature when they are between 10 and 13 years old. Females usually produce babies every six years (after a pregnancy lasting eight months). There are three subspecies (that may be more genetically variable than humans):
1. The western subspecies (P.t.verus) can be found in the Côte d'Ivoire and Guinea, Sierra Leone, and Liberia.
2. The central subspecies (P.t.troglodytes) is found throughout seven central African countries. The most serious threats posed in these areas are habitat loss and hunting for meat.
3. The eastern subspecies (P.t. schweinfurthi), which lives in eastern Zaïre, the western forests of Uganda and Tanzania, with a few small scattered groups in Rwanda, Burundi, and Sudan.
IUCN lists chimpanzees as Endangered. Habitat alteration, through logging in the tropical rainforests of central Africa or habitat destruction for agriculture in the densely populated countries of west and eastcentral Africa, pose the most serious threat to chimpanzees, together with commercial hunting for bushmeat.
Social behaviour
Chimpanzees live in social groups of between 20 and 100 individuals. However, all the individuals in a group are rarely, if ever, together. They travel around their territory of several square miles in ever-changing parties. Mothers travel with their dependent children (up to the age of six to ten) and may be joined by other mothers or one or more of the males. Individuals may also travel alone. Parties are generally larger when there is an abundant source of food (a rich fruit tree) or one of the females is in oestrus. When parties meet, there often is a lot of excitement, with the chimps hooting, touching and patting one another, subordinates behaving submissively to dominants, etc. Males always stay in the group in which they are born, they would be attacked if they went to another group. In fact, male chimpanzees sometimes go on patrols wih other males, walking silently, scanning the environment for any sign of chimps from other groups. When they do meet with a single male from another group, they will attack him and wound him severely. If they spot a larger party, they retreat silently. When they reach puberty, females may transfer to another group. Matings only take place when females are in oestrus. Several males may mate with an oestrus female, although the most dominant males try to monopolize them. But a complete monopoly is impossible, in part because males may take a female on a 'consort' to the periphery of the home-range.
Males sometimes spend a lot of effort to become the most dominant male. To achieve this position, they use a lot of bluff-displays and often have to cooperate with other males. These coalitions between males may change, thus leading to a system of 'chimpanzee politics'.
Youngsters are raised exclusively by their mothers, the males play no role in this respect, it is not clear who is the father of which youngster. Chimpanzee children have to learn a lot about getting food and about social relationships (e.g. about reconciliation, about enlisting support) when they grow up. Social play is a common activity, when playmates are available, and probably serves to practice muscles and skills. Youngsters also 'tease' adults by throwing objects at them etc, in order to learn about the way in
which adults react to them.
Fact sheet, including information about chimpanzee communication
Chimpanzee Ethogram
Longterm chimpanzee research projects are in progress in a number of areas: Tai, Côte d'Ivoire; Kibale, Uganda; Boussou, Guinea; Lopé, Gabon - the longestrunning sites being Gombe and Mahale in Tanzania.
The evidence is overwhelming that chimpanzees have a remarkable ability to invent new customs and technologies and that they pass these on socially rather than genetically
Chimps dig clean water:
Chimpanzees dig holes in the sand near pools of stagnant water in riverbeds, allowing relatively clean water to well up from the water table
Article by Michael A. Huffman
And the latest (2003) twist in the debate over how much DNA separates humans from chimpanzees even suggests we are so closely related that chimps should not only be part of the same taxonomic family, but also the same genus.
Female chimpanzees of high rank have significantly higher infant survival, faster maturing daughters, and more rapid production of young. Given the foraging behavior of chimpanzees, high rank probably influences reproductive success by helping females establish and maintain access to good foraging areas rather than by sparing them stress from aggression
The issue of whether chimpanzees have a Theory of Mind is still not settled.
In 2002, chimpanzees with little or no human contact were found in remote African rainforest
