The African Great Ape
The common chimpanzee is an ape that lives in tropical Africa. It is omnivorous, predominantly frugivorous, largely arboreal and diurnal. Genetically, the chimpanzee
shares more than 98% common heritage with humans.
With gorillas, the common chimpanzee is the only other representative of great apes on
the African continent. They are classified in the order of primates, hominid family and
genus Pan.
We distinguish two types :
· The common chimpanzee (Pan troglodytes), the participants of HELP.
· Pygmy chimpanzee or bonobo (Pan paniscus), living in the Democratic Republic of
Congo (formerly Zaire).
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Photo © Stéphane CHAMAYOU - HELP CONGO |
Among common chimpanzees, there are four subspecies :
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les Pan troglodytes troglodytes (Central Africa, particularly in the Republic of Congo)
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les Pan troglodytes schweinfurthii (East African)
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les Pan troglodytes verus (West African)
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les Pan troglodytes vellerosus (also known as Nigeria-Cameroon chimpanzees)
Morphology similar to humans
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The body of the chimpanzee is perfectly suited to climb and swing from trees.
Chimpanzees have long disproportionate arms (compared to humans), which facilitate
access to branches. They also have very flexible and prehensile hands and feet. These
attributes allow them to move from branch to branch without breakage under their
weight.
Like humans, they do not have bristle on the face, or palms and feet. Their fingers are
reduced, with curved nails. Common chimpanzees have powerful molars, and standing
males can reach up to 3 meters in height; females are slightly smaller.
Their coat is often dark; although, length, color and body distribution will vary with age,
subspecies, and the individual. These young chimps have black hair, pinkish faces and
tuft of white hair on the hindquarters that disappears after several years. With age, the
face is darkens and hair recedes on the face and head. |
Photo © Stéphane CHAMAYOU - HC |
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A territory of 21 countries
It is the common eastern chimpanzee in Democratic Republic of Congo, Uganda,
Tanzania, Burundi, Rwanda, Sudan and Central African Republic.
The common chimpanzee of Central Africa lives in Cameroon, Gabon, Republic of
Congo, Equatorial Guinea, Central African Republic and Angola.
As for the western chimpanzee, they are found in Guinea, Côte d'Ivoire, Mali, Liberia,
Guinea-Bissau, Sierra Leone, Senegal and Ghana.
Finally, the fourth subspecies is in Nigeria and Cameroon.
The habitats vary from humid dense forests, to the dry forests and savannas where
people live, through swamp forests or mountains.
A both quadrupedal and bipedal species
Chimpanzees move on the ground in a unique quadruped position (as do gorillas) called "knuckle-walking" (the weight of the upper body is supported by the dorsal surface of the middle phalanges fingers).
On the ground, chimpanzees can also adopt a bipedal walking, especially during demonstrations of dominance or through certain obstacles like small area of mud or water areas.
Chimpanzees cannot swim. Some are even afraid of the water, especially if this element is not present in their environment.
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Photo © Stéphane CHAMAYOU - HELP CONGO |
Varied eating habits
Chimpanzees spend almost half of their time feeding and move from one feeding
ground to another. They eat most often in trees, and eat the bulk of their food between
7 and 9 am and between 3:30 pm to dark.
Dietary diversity in chimpanzees is remarkable. They eat seeds, nuts, fruits, flowers,
leaves, stems, sap, bark, honey, insects (like ants, termites) and sometimes other
animals (especially smaller monkeys). Very often, meat consumption is accompanied
with leafy greens.
All chimpanzees are able to hunt, but in general, it is the males who form hunting
groups. They can hunt wild pigs, antelopes (usually newborns) and especially monkeys.
Hunting behavior shows strong variations among populations of chimpanzees.
Chimpanzees also eat plants that are well known for medicinal and therapeutic
properties, including digestive aids.
Chimpanzees use tools. Within a group, juveniles learn how to use the various tools by
watching their parents and imitating the actions of their mothers and seniors. The
common western chimpanzee uses stones to break nuts, while subspecies in central
Africa use pieces of wood for hammering. To collect termites chimpanzees in Central
Africa using twigs to reach inside the nests, as the termites attack foreign bodies in the
nest, the climb on the twig and are consumed. Chimpanzees use this same technique to
collect ants.
A complex social structure
The social structure in the common chimpanzee is described as "fusion-fission".
Communities are made up of sub-groups ranging in number and composition, which
come together (fusion) or split (fission) depending on the circumstances. Members of a
community share a common living space, and the number of individuals may vary from
20 to 80.
Several types of communities have been encountered :
Males only
Adult females with bisexual children
A female and her offspring
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Very violent fights for dominance can sometimes occur between males in neighboring
communities, causing severe injury or death. Males tend to stay in the community
where they were born; the older they get, the more they associate with other males and
integrate into the hierarchy. In contrast to males, females tend to move away from their
home, especially after reaching maturity.
Chimpanzee infanticide often occurs when there is a doubt about the paternity of a
child or when an adult male kills the child of an unfamiliar female. |
Photo © Stéphane CHAMAYOU - HELP CONGO |
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A defined territory
Like many mammals, chimpanzees are sedentary and focus their activities on a limited
area corresponding to their home range. For chimpanzees, this is an average of about 7
km².
Many means of communication
The means of communication between individuals, subgroups or even between
different communities are varied and often quite complex.
Visual communication plays an important role in their society. Chimpanzees use many
postures or significant gestures -
"Open mouth grin" : (the mouth is open with lips pulled back and visible teeth) when an
individual is threatened by another placed higher in the hierarchy.
"Open mouth threat" : (the mouth is open but the teeth are covered by the lips and eyes
seek a mate) to scare a subordinate
"Play face" : (eyes and mouth are open but the teeth are not visible) in the game with
peers and children.
And many more...
In voice communication, chimpanzees use three main cries or grunts -
"Pant-hoot" : (a series of vocal breathing often ending with screaming) when feeding site is
found, among other reasons.
"Pant-grunt" : (low growls emitted by subordinate to the dominant individual) response to
a show of dominance.
"Wraaa" : a cry is heard when the animals are afraid.
Tactile communication between individuals is very important, and are generally
distinguished into -
"Reaching / touching" : An individual touched with the hand or the head to the back or
rump of another, as a gesture of healing and comfort.
"Embracing" : The wrapping of one or two arms around an individual. This gesture is often
observed between a mother and frightened child.
"Submissive mounting" : A junior mounts a dominant after being charged or attacked.
"Reassurance mounting" : A dominant mounts a junior in response to a "social
presentation".
"Social grooming" : Removing dead skin and parasites from another individual. This helps
maintain and reinforce social ties. This behavior is frequently observed between males,
and especially between a subordinate to a dominant. In the common chimpanzee, it
also occurs between members of the same family.
Strong bonds between mother and child
In general, the common chimpanzee gives birth to a single baby; twins are very rare.
There is a minimum three-year interval between births, but a gap of five or six years is
more frequent in successful survival of the offspring. A female can give birth once a year
if a child is killed or confiscated during the first months of life.
uring the first three months, the child is cradled by the parent in a sitting position.
Until the age of six months, the child clings to his mother's belly during transport, and
migrates to the back in the following years. Weaning takes place between 3 ½ and 4½ years, but the young may remain dependent on its mother for many years, often until
the age of 10 years.
Puberty is reached at 7 years for both sexes, and females do not usually give birth
before reaching age 13 or 14. However, they are able to still give birth until the age of
40. Older females are more popular than youth, who often have to leave the
community, either temporarily or permanently. The males, meanwhile, are not
integrated into the social structure before 15-16 years. |
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Photo © Stéphane CHAMAYOU - HELP CONGO |
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