Celebes crested macaque Celebes crested macaque 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 Tangkoko reserve in the northeastern tip of the Indonesian island of Sulawesi (Celebes), as well as on smaller neighboring islands. Locally known as "yaki" or "wolai", its skin and hairless face is, with the exception of some white hair in the shoulder range, entirely jet black. Unusual for a primate, it has striking reddish-brown eyes. The long muzzle with high cheeks and the long hair tuft, or crest,
Barbary macaque males who have helped them in the past, this is not as important as relatedness in determining coalitions. Males avoid conflicting with higher ranking males and will more frequently form coalitions with the higher ranking male in a conflict. Close grouping of males occur when infant Barbary macaques are present. Interactions between males are commonly initiated when a male presents an infant macaque to an adult male who is not caring for an infant, or when an unattached male approaches males who are caring for infants. This behaviour leads to a type of social buffering, which reduces the number of