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Facts About Celebes Crested Macaques

Chandramita Bora
Celebes crested macaques can be identified by the characteristic crest on top of their head. They are native to the Sulawesi island of Indonesia, which was earlier known as Celebes. In this story, we present some interesting facts about these monkeys.

Did You Know?

Celebes crested macaques have been observed to greet one another by embracing and sniffing each other's rear end.
The Celebes crested macaque is an Old World monkey belonging to the Cercopithecidae family. Its scientific name is Macaca nigra. This monkey is native to the Sulawesi or Celebes island of Indonesia and other smaller neighboring islands. It is also known by the names Crested black macaque, Sulawesi crested macaque, and the black ape.
However, the name 'black ape' is a misnomer, as Celebes crested macaques are monkeys and not apes. Like other monkeys, they also possess a tail, but the tail is somewhat rudimentary, or too short, and this may be the reason why some crested black macaques were misidentified as apes in the past.
Crested black macaques are unique monkeys and can be easily distinguished from other monkeys by their striking features and characteristics.

Interesting Facts about Celebes Crested Macaques

Physical Appearance

✦ Crested black macaques are jet black in color, except for their pink, hairless rumps. The rumps of male monkeys are somewhat heart-shaped and smaller than those of females. Females possess much larger buttocks that are dark pink in color.
✦ Celebes crested macaques are medium- to large-sized monkeys, with an elongated face and muzzle. The face is completely black in color, and usually hairless or sparsely covered with hair. The cheekbones and brow ridges are particularly prominent in these moneys.
✦ Their body hair is dense, coarse, woolly, and black in color. The juvenile and female macaques are somewhat paler than adult males. Celebes crested macaques possess a very short tail, that hardly reaches a length of 2 cm.
✦ The most distinguishing characteristic of crested black macaques is the tuft of short and coarse hair on their crown, that forms a pointed crest. This crest somewhat resembles the famous mohawk hairstyle.
✦ Sexual dimorphism is well-evident in Celebes crested macaques. Males are usually bigger than females and possess larger canines as compared to their female counterparts. Male monkeys are usually 520 to 570 mm in length, while females can reach a length of 445 to 570 mm. On an average, a Celebes crested macaque can weigh 22 pounds.

Habitat and Distribution

✦ Celebes crested macaques are restricted to the northeastern parts of the Sulawesi island and other neighboring islands. They are mainly found in tropical rainforests and mangrove swamps.
✦ They can also inhabit coastal and secondary forests. Sometimes they can frequent agricultural areas as well, though the density of population is low in non-forest habitats.
✦ In Sulawesi Island, they are mainly found in protected areas, like the Tangkoko Batuangus Nature Reserve, the Gunung Lokon, Gunung Ambang, and Gunung Manembo-nembo Nature Reserves, and the Bunaken Marine National Park.

Life Cycle

✦ The average lifespan of crested black macaques is 18 to 20 years. Male monkeys attain sexual maturity at about 4 to 5 years of age, while females are sexually mature at the age of 3 to 5 years.
✦ In crested black macaques, breeding can occur any time of the year. Both males and females are promiscuous. The gestation period is approximately 162 to 186 days, after which the female gives birth to a young. The young ones are nursed for approximately one year.
✦ A peculiar characteristic of female black crested macaques is that their buttocks or rumps become extremely swollen, and turn bright pink or red in color when they are ready to mate.

Other Interesting Facts

✦ Celebes crested macaques are basically frugivorous, though they sometimes also eat insects, small invertebrates, reptiles, and even birds and bird eggs. Their main diet includes fruits, leaves, roots, seeds, sprouts, buds, and flowers.
✦ Crested black macaques are social monkeys and live in large groups, which are termed as troops. A group includes males, females, and their young. In areas where their population is dense, a troop of crested black macaques can sometimes include more than 100 individuals.
✦ Smaller groups usually contain a single male, while there can be several males in a larger group. Usually, the ratio of female to male monkeys in a group is about 4:1.
✦ Female monkeys are permanent members of a troop, while males are usually not allowed to remain in their mother's troop once they reach sexual maturity.
✦ Female monkeys, on the other hand, stay in their mother's troop. They hold different ranks in a group, which they inherit from their mothers.
✦ As mentioned already, male crested black macaques possess larger canines than females, which they use in hostile encounters with other males, especially when they compete for a female. Sometimes, the males yawn to exhibit their large canines in an attempt to assert their dominance in the group.
✦ Apart from displaying their teeth, crested black macaques can communicate verbally with grunts, and also by smacking their lips. They can also move the tuft of hair present on their crown to express their emotions.
✦ Grooming is also an important aspect of their social behavior. Individual members of a group maintain their relationship by grooming each other. It has been observed that female crested black macaques spend more time on grooming than males.
✦ Crested black macaques are diurnal, and spend their time both on the ground and on trees. More than 60% of the day is spent on the ground looking for food and socializing. During the day, these monkeys split into smaller groups of 10 to 25 individuals to forage for food, but return to the trees for sleeping.
Despite their fearsome appearance, Celebes crested macaques are quite gentle. Unfortunately, their numbers have been declining in the last few years, mainly due to loss of habitat and hunting. All these factors have led to a considerable decline in their population. As per estimates, the population of these primates has gone down by more than 80% in the last 40 years. Presently, they are enlisted as 'Critically Endangered' on the IUCN (International Union of Conservation of Nature and Natural Resources) red list of threatened species.