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 the Indonesian island of Sulawesi (Celebes) as well as on smaller neighboring 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 tuft, or crest, at the top side of the head are remarkable. The tail is only approximately 2 cm (1 in) of stub. With a total body length of 44 cm (17 in) to 60 cm (24 in) and a weight of 3.6 to 10.4 kg, it is one of the smaller macaque species. Its life expectancy is estimated at approximately 20 years.
The Celebes crested macaque is promiscuous, with both males and females mating multiple times with multiple partners. The receptivity of the females is clearly indicated by an extreme tumescence (swelling) and redness of their buttocks which, in contrast to the black skin color, is particularly remarkable.
The gestation time is 174 days, and the birth of the usually single offspring happens in the spring when food is more plentiful. Young animals are nursed approximately one year and become fully mature in 3 to 4 years, females somewhat sooner than males.