Bonobos have black hair and black faces from birth, and pink lips, small ears, and wide nostrils. The long hair on the head looks as if it is parted and bonobos do not tend to go bald with age. Bonobos are born with a white tail tuft. The bonobo has a slim upper body, thin neck, narrow shoulders, and long legs.
Often confused with the common chimpanzee, the bonobo is generally considered to be the more gracile species, and has noticeably smaller head and ears, a flatter face, and a less prominent brow ridge. Adult bonobos retain the white tail tuft that common chimpanzees lose after infancy.
Body mass in male bonobos ranges from 34 to 60 kg (75 to 132 lb), against an average of 30 kg (66 lb) in females. From the nose to rump while on all fours, adult male bonobos measure 73 to 83 cm (2.4 to 2.7 ft), females 70 to 76 cm (2.3 to 2.5 ft). When adult bonobos stand up on both legs, they can attain a height of 115 cm (3.8 ft).
Bonobos occur only in DR Congo
, and are confined to an island-block of forest comprising approximately one-fifth of the country. Their range extends from the Lualaba River in the east, to the Kasai/Sankuru Rivers in the south, and to the west as far as to the Bolobo village and around the Lake Tumba/Lac Ndombe area.
The extent of their potential range is estimated at approximately 500,000 km². Within this large forest zone, bonobos are absent or rare in many areas and common only in a few scattered localities.
Female bonobos reach sexual maturity at approximately 12 years of age. The gestation period is 220-240 days. They normally give birth to a single young. Offspring have a black face and hands, with ears hidden behind whiskers. The young are cared for until they are 4-5 years old, and females have 5-6 offspring in their lifetime.
A male bonobo remains with his mother’s group for life, whereas females leave the maternal group for another at maturity. The lifespan of bonobos in the wild is unknown, and 40 years in captivity.