Pagai Island macaque a result, the water levels in the forest rivers fluctuate to a much greater degree than before. The alternating flooding and low water levels has also caused an increase in the population of malarial mosquitoes. Pagai Island macaque The Pagai Island macaque ("Macaca pagensis"), also known as the Pagai macaque or Bokkoi, is an Old World monkey endemic to the Mentawai Islands off the west coast of Sumatra. It is listed as critically endangered on the IUCN Red List due to its ever-shrinking habitat. "Macaca pagensis" formerly included the overall darker Siberut macaque as a subspecies, but this arrangement is
Celebes crested macaque at the top of the head are remarkable features. It has an "apelike" appearance due to its almost non-existent, non-visible, vestigial tail stub of only approximately . With a total body length of to and a weight of to , it is one of the smaller macaque species. Its life expectancy is estimated at approximately 20 years in the wild. The Celebes crested macaque is a diurnal rain forest dweller. This macaque is primarily terrestrial, spending more than 60% of its day on the ground foraging for food and socializing, while sleeping and searching for food in the trees. The