Chimpanzee

Taxonomy:
Subspecies: West African chimpanzee (Pan troglodytes verus)
Subspecies: East African chimpanzee (Pan troglodytes schweinfurthii)
Subspecies: Central African chimpanzee (Pan troglodytes troglodytes)
Subspecies: East Nigeria/West Cameroon chimpanzee (Pan troglodytes vellerosus)

Distribution: Ivory coast, Liberia, Sierra Leone, Guinea, Senegal, Congo

Chimpanzees and bonobos are humans’ closest living relatives; different studies have shown that 98% of their DNA is identical to that of Homo sapiens.
In their natural habitats, wild chimpanzees live in big communities which split into subgroups and meet occasionally (a “Fission-Fusion system”). Chimpanzees feed on fruit and leaves and (mostly males) also hunt for monkeys and duikers.
Offspring are dependant on their mothers for approximately 4-10 years. From the age of 10-12 years females will disperse from their natal group, whereas males will usually stay in their natal group for life.
Of all great ape species it is the chimpanzee that has most frequently been observed using and making tools, and has been found to possess local social and technological traditions.
Living in a social system that requires cooperative behavior has been proposed as one of the reasons for chimpanzees’ high cognitive abilities

Bonobo

Distribution: Democratic Republic of Congo (former Zaire).

Much less observational data exists for bonobos compared to chimpanzees.
Bonobos have a similar appearance to their close relative, the chimpanzee, but can be distinguished by their gracefulness, slender extremities and red lips. Like chimpanzees, they also live in so-called “Fission-Fusion” societies. However, their social structure differs from the chimpanzees’: In Bonobo groups, females are dominant over males and they conciliate conflicts more peacefully, using sex and grooming.
Bonobos feed mainly on fruit, leaves and herbs with high protein content (THV = terrestrial herbaceous vegetation) to cover their protein requirements. This could also explain their lower hunting rates (compared to chimpanzees). Unlike chimps, it is largely the females who have been observed hunting in bonobo groups.
In the wild, bonobos have been observed walking upright for approximately 25% of their total ground locomotion.

Orangutan

Taxonomy:
Species: Bornean Orangutan (Pongo pygmaeus)
Subspecies: Western Bornean orangutan (Pongo pygmaeus pygmaeus)
Subspecies: Southern Bornean orangutan (Pongo pygmaeus wurmbii)
Subspecies: Eastern populations (Pongo pygmaeus morio)
Species: Sumatran Orangutan (Pongo abelii)

Distribution: Borneo, Sumatra

Orangutans are the most arboreal of the four great ape species. They feed mainly on fruit and can accumulate considerable fat reserves which might be an adaptation resulting from the seasonal changes in fruit availability.
Orangutans spend most of their time living solitarily. The males inhabit large territories which include several smaller habitats where mothers live with their dependent infants. However, it has been observed that these home ranges overlap and that individuals gather when plenty of food is available.
In adult male orangutans, there are two physiognomic types; the unflanged (or “sneaker”) type and the flanged type with cheek flaps (= flanges) and a throat pouch. After reaching sexual maturity, males usually spend a period of time as sneakers, who have the physical appearance of a female. They will roam through female habitats until they establish their own, where they will then develop into flanged males.

Gorilla

Taxonomy:
Species: Western Gorilla (Gorilla gorilla)
Subspecies: Western Lowland Gorilla (Gorilla gorilla gorilla)
Subspecies: Cross River Gorilla (Gorilla gorilla diehli)
Species: Eastern Gorilla (Gorilla beringei)
Subspecies: Mountain Gorilla (Gorilla beringei beringei)
Subspecies: Eastern Lowland Gorilla (Gorilla beringei graueri)

Distribution: Central African Republic, Cameroon, Congo, Equatorial Guinea, Nigeria, Gabon, Angola

Gorillas form the most stable social groups of all the great apes. They usually live in harems with an average of 10 individuals, including one or several silverback males, females and subadults.
Males often leave their natal troop and prowl solitarily as adolescent blackbacks until either they join a group of other blackbacks or take over a group of females and develop into silverbacks. Females transfer repeatedly between harem groups but never wander without male company. Gorillas live on a diet of fruit and plants which are rich in cellulose and can only be digested by the microbes in the gorillas’ colons.
Gas is produced as a by-product of this process, which causes the gorillas’ characteristic bloated bellies.
Physical contact between individuals occurs at a much lower rate than in the other great ape species.