Crested black macaque, Sulawesi crested macaque, Black ape, Yaki, Wolai
The Celebes crested macaque is a large primate with distinctive kidney-shaped, bright pink ischial callosities. The tail is short, having form of a nubbin. The body is black, covered with rough, thick and wooly fur. The black face of the primate is coated with dense layer of hair. Compared to other macaques, their skull is more projecting and baboon-like. Hairs on the top of their head compose a crest, facing up and backward. The coloration of young macaques is noticeably paler, closer to brown than black. They have black hairs on their crown, where further the crest appears. Older males can be identified by grizzled coat, especially in their upper body. Meanwhile, the same color can sometimes be found on the arms of younger males.
Currently, the species inhabits island Pulau Bacan, Tangoko Reserve and north-eastern part of Sulawesi island in Indonesia. On island Sulawesi, the Celebes crested macaques are mainly found within protected areas, including Tangkoko Batuangus Nature Reserve, Gunung Ambang, the Gunung Lokon, the Bunaken Marine National Park as well as Gunung Manembo-nembo Nature Reserve. These primates live in humid environment, preferring habitats such as tropical lowland and upland rainforests as well as agricultural areas, which have occupied some parts of their natural range.
Celebes crested macaques are diurnal animals, socializing in the morning and resting in the afternoon. When awake, they spend about 59% of their time moving, foraging and feeding. These terrestrial primates typically sleep in trees. The macaques travel 2.4 km a day on average. Meanwhile, those, living in primary forests, usually spend less time travelling due to abundance of fruit they feed upon. The Celebes crested macaques are highly territorial animals, gathering into groups. Groups of this species are very large for their genus, containing 50-97 primates, majority of which are females. Male macaques typically show submission and satisfaction by making a grimace or smacking their lips. Meanwhile, to express aggression, they yawn, chase, stare with an open mouth as well as grin with their mouth closed.
These animals are primarily frugivorous, feeding upon fruits and especially – figs. However, their diet is rather diverse, consisting of up to 145 species of plants and invertebrates. So when fruits are hard to find, the macaques can consume young leaves, shoots, stems of flowering plants as well as insects.
These primates have polygynandrous mating system, where both males and females mate with multiple mates. The macaques mate throughout the year with peak activity period among adult females, lasting from August to June. Females give birth with an interval of 18 months with gestation period of 5.5 months, yielding a single baby, usually between January and May. Reaching the age of 4 months, young macaques begin to spend less time with their mother, and are eventually weaned at 1 year old. Maturity is reached by the age of 3-4 years.
One of the major threats to the population of Celebes crested macaques is hunting: on the island Sulawesi, where these primates live, their meat is considered a delicacy, which brings to a large-scale hunting on this species. Other notable threats include deforestation, extension of human habitat and alteration of their natural range into agricultural areas.
On the IUCN Red List, this primate is classified as a Critically Endangered species. The overall population of Celebes crested macaques varies from 4,000 to 6,000 individuals throughout Sulawesi Island, and approximately 100,000 – on the Pulau Bacan Island.
Due to feeding upon various fruits, these animals are important seed dispersers throughout their range, aiding some rainforest trees such as Ficus or Dracomelon.
