Pagai Island macaque

The Pagai Island macaque, also known as the Pagai macaque or Bokkoi, is a critically endangered Old World monkey native to the Mentawai Islands, located off the west coast of Sumatra. Previously believed to be a subspecies of the Siberut macaque, it is now recognized as a distinct species.

These macaques exhibit notable sexual dimorphism, with males being larger than females. Males generally measure between 45 to 55 cm in body length, while females range from 40 to 45 cm. They have dark brown backs, reddish-brown arms, and black-skinned faces highlighted by brown eyes.

Pagai Island macaques primarily inhabit rainforests, where they forage for figs and live in social groups of 5 to 25 individuals, led by a dominant male. They spend most of their time high in the canopy, foraging at heights between 24 and 36 meters and often sleeping as high as 45 meters above the forest floor. Equipped with cheek pouches for storing food and a distinctive bark to alert the group to predators, these monkeys are well-adapted to their arboreal lifestyle.

Females show signs of fertility through swollen genitals and initiate mating by crouching. After a gestation period of 5 to 6 months, they give birth to a single offspring at night. The mother consumes the placenta and provides dedicated care to her newborn.

Unfortunately, the Pagai Island macaque population is rapidly dwindling due to habitat loss. Deforestation for cash crops and oil palm plantations, along with commercial logging, has severely impacted their environment. Additionally, the destruction of forests has led to fluctuating water levels in forest rivers, increasing the prevalence of malarial mosquitoes.

Currently, these macaques are found on three of the major Mentawai Islands and are listed as critically endangered by the IUCN Red List. Urgent conservation efforts are essential to prevent their extinction.