Distribution
W & C Africa, N of River Zaire, from Senegal to Tanzania.
Habitat
Humid forest, deciduous woodland or mixed savanna; presence in open areas
depends on access to evergreen, fruit-producing forest; sea level to 2,000m
(6,560ft).
Current population
Estimated 150,000 - 235,000 (Luoma 1989).
Size
Head and body length 63.5cm-94cm. Height when erect 1.0-1.7m. Arms spread is 50%
greater then the animals height. Males are larger and stronger th
an females, with bigger canine
teeth which are used in severe fights.
Weight
In wild, 34-70kg for males and 26-50kg for females, respective figures for captives are
80kg and 68kg.
Life expectancy
40-45 years.
Diet
The common chimp is a vegetarian, feeding on ripe fruits for 4 hours a day and young
leaves for 1-2 hours. During the dry season, tree seeds partly replace fruit and flowers, soft pith,
galls, resin, bark, honey, insects, eggs and meat are also take
n. Annually food intake consists
of 60% fruits, 30% other vegetation and 10% meat. Social insects (eg termites) provide the bulk
of the animal matter eaten. However, they also take bush pigs, baboons and deer- although
more than one chimp may take part i
n the chase, they do not appear to hunt cooperatively and
once a kill is made there is intense competition. Feeding is essentially an individual activity.
Cannibalism on infant chimps has been observed by males of a community into which a mother
has rece
ntly migrated.
Community Structure
Chimpanzees live in communities 15-120 strong, these are loose and
flexible associations of males and females who share a home range. Within these communities
individuals have their own 'core' areas and s
pend 80% of their time in these. Each animal has
its own network of social contacts. A community has a dominant male leader.The entire
community rarely congregates together in the same place. Males seldom leave the community
into which they are born, but
females generally leave migrate to a new community during an
adolescent oestrous period. A successful transfer occurs for a female once she has established
her own core area in the new community and can feed without aggression from other females.
Relati
onships between females are poorly understood but range from aggressive to friendly.
Male chimps tend to associate with their maternal brothers but will associate with other males
as well. Although males are commonly aggressive to each other they also ac
tively seek out and
groom one another. Grooming to remove dirt and external parasites is important in maintaining
friendly relations and can also be used as a means of exchange to gain favours from another
individual.
Communication
Complex,
involves constantly varying facial expression, numerous gestures
and 24 identified vocalisations.
Territoriality
Community borders are patrolled by male parties and outsiders may be attacked
and killed.
Reproduction and care of youn
g
There is no breeding season. Females only mate when
they are in heat and may be promiscuous or form an exclusive 'consortship' with a single male.
Females are not receptive for 3-4 years after giving birth but generally will not have another
ba
by for 5-6 years if the first young survives.
Young ride on the mothers back for several years, are weaned between 3.5 and 4.5 years but
may still travel with her at age 10. Bonds between mother and young may persist throughout
life.
Tool use< BR> Uses modified sticks or vines to poke into the entrance of a termite nest, withdrawing the tool once it has become covered in insects. Sticks are also used as hooks to pull down fruit- laden branches, and as weapons during inter- and intra-specific f ighting. Stones are also used to crack open fruits with hard shells. These skills are culturally acquired by the young observing more experienced chimps.
Leaves may be used as sponges to soak up drinking water and as tissues for cleaning the body.
Previous geographical spread
Known in a further 9 countries but now probably extinct in
these.
Reasons for decline
Reduced and fragmented by loss of forest habitat, particularly
commercial logging eg in Ivory Coast and central
Zaire, hunting by people for bushmeat in eg
Sierra Leone and eastern Zaire and to protect crops and commercial exploitation for the animal
trade.
Current threats
Demand for animals for biomedical research, especially involving work relate
d
to Acquired Immune Deficiency Syndrome (AIDS). In Gabon numbers declining rapidly due to
intensified logging and environmental disruptions (Tutin and Fernandez 1984).
Conservation projects
In some areas chimps are protected by local cust
om eg parts of
Guinea, Zaire and Tanzania.
Status
1990 USDI reclassified as endangered in the wild. On appendix 1 of CITES.
File last modified Thursday, October 3, 1996