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.
They have black hair and pinkish to black bare skin on their faces (except for hairs on the chin), ears, palms of their hands, and soles of their feet. Infants have very pale skin in these areas and a white tail tuft, which disappear by early adulthood.
Chimpanzees walk on all fours, or
"quadrupedally," on the ground and in the trees. They use
their knuckles for support while walking on all fours, and are called
"knuckle-walkers." This form of locomotion gives chimpanzees
longer arms than legs. The chimpanzees can use these long arms to reach
out to fruits growing on thin branches that would not usually support
their weight and "brachiate" (swing from branch to branch by
their arms).
Chimps have opposable thumbs,
although these are much shorter than human thumbs, and their opposable
big toes enable a precision grip. Chimpanzee males are slightly larger
and heavier than females. At Gombe, adult males weigh between 90 and 115
pounds and measure about 4 feet high when standing upright. Females are
slightly smaller. Chimpanzees in West Africa, and in captivity, may be
larger. Chimpanzees in the wild seldom live longer than 50 years. Some
captive individuals have lived more than 60 years.
Chimpanzees eat fruits, leaves,
blossoms, seeds, pith, bark and stems. They also eat a variety of
insects and hunt and kill smaller mammals for meat. Their most common
prey is the red colobus monkey.
During
their first year, chimpanzees are in constant physical contact with
their mothers. At around 2 years of age, they will venture a small
distance from their mothers and they no longer travel only on her back.
Mothers wean infants between the ages of 4 and 6 – often a very trying
period for the young chimp! Typically chimpanzees become independent
between 6 and 9 years old. They will have lifelong bonds with their
mothers, but will become much more independent. Adolescent females
sometimes join nearby chimpanzee groups for periods of time while older
males stay within their group and spend time with other males.