The Celebes Crested Macaque (Macaca nigra), also known as the Crested Black Macaque, Sulawesi Crested Macaque, or the Black Ape, is an Old World monkey that lives in the northeast of Indonesian island of Sulawesi (Celebes) as well as on neighbouring islands. Its skin and hairless face is, with the exception of some white hair in the shoulder range, entirely jet black. The long muzzle with high cheeks and the long hair crest at the top side of the head are remarkable. The tail is only 2 cm of stub. With a total body length of 45 to 60 cm and a weight of 7 to 10 kg, it is one of the smaller macaque species. The Celebes Crested Macaque is a diurnal rain forest dweller. It lives in groups of 5 to 25 animals. Smaller groups have only a single male, while larger groups have up to four males. The females, however, always outnumber the males by about 4:1. Since young males must leave their birth group upon maturity, they sometimes form bachelor groups before they look for a connection to a mixed group. Communication consists of sounds and gestures; such as the presentation of long eyeteeth while grimacing in a clear threatening gesture. The Celebes Crested Macaque is frugivorous, with 70% of its diet consisting of fruits. It also consumes leaves, buds, seeds, fungus, birds and bird eggs, insects, small lizards and frogs. The Celebes Crested Macaque is promiscuous, with both males and females mating multiple times with multiple partners.