Pagai Island macaque

Last updated

Pagai Island macaque [1]
Beruk Mentawai Macaca pagensis.JPG
Captive Pagai Island macaque, Cisarua, West Java, Indonesia
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Suborder: Haplorhini
Infraorder: Simiiformes
Family: Cercopithecidae
Genus: Macaca
M. pagensis
Binomial name
Macaca pagensis
(Miller, 1903)
Pagai Island Macaque area.png
Pagai Island macaque range

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 polyphyletic, [3] leading to the two being classified as separate species. Both were formerly considered subspecies of the southern pig-tailed macaque. [1]



Pagai Island macaque males are generally larger than females. The males' body lengths range from 45–55 cm and females' body lengths are around 40–45 cm. Tail length is 13–16 cm for males and 10–13 cm for females. Males are also heavier, weighing around 6–9 kg while females weigh 4.5–6 kg. Their backs have a dark brown coloration, and chestnut to pale ochre on the sides of the neck, the front of the shoulders and the undersides of this species. Legs are brown and their arms, reddish brown. The faces of Mentawai macaques are furless and black-skinned with brown eyes. They have cheek pouches to carry food while foraging.

Habitat and ecology

The macaques' natural habitat is rainforest, but they can also be found in riverine and coastal swamp-forests. They live high above the forest floor in the canopy, forage between 24 and 36 meters and may sleep as high as 45 meters. The primary food of the species is figs. They may split into splinter groups to forage for food and to sleep. They will eat alongside groups of Mentawai langurs. M. pagensis groups consist of around five to 25 individuals. Typically, a group consists of a single male with adult females and their offspring. The male decides where to go and communicates this to the rest of the group with high-pitched cries. Roaming, solitary Pagai Island macaques may challenge the dominant male for his position, leading to aggressive fights. The natural predators of the species are the crested serpent eagle and the reticulated python. When these predators are spotted, the macaques will alert the rest of the group with a short, gruff bark.


Females show fertility and willingness to mate by displaying their swollen and reddened genitals. Females crouch to initiate mating. The gestation period is between five and six months. A single offspring is born during the night. The mother eats the placenta and licks the infant clean before morning. The mother and young share a close bond into adulthood.

Population and threats

The species' primary habitat is on the Mentawai Islands 150 km off the west coast of Sumatra. They populate three of the four major islands in the chain (North Pagai, South Pagai and Sipura). Due to deforestation by immigrants from the Indonesian mainland, the species is now listed as critically endangered on the IUCN red list. The primary reasons behind deforestation on the island are the clearing of large areas of land for cash crop and oil palm plantations, as well as commercial logging. As 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.

Related Research Articles

Crab-eating macaque Species of mammal

The crab-eating macaque, also known as the long-tailed macaque and referred to as the cynomolgus monkey in laboratories, is a cercopithecine primate native to Southeast Asia. A species of macaque, the crab-eating macaque has a long history alongside humans; it has been alternately seen as an agricultural pest, sacred animal in some temples, and more recently, the subject of medical experiments.

Old World monkey Family of mammals

Old World monkey is the common English name for a family of primates known taxonomically as the Cercopithecidae. Twenty-four genera and 138 species are recognized, making it the largest primate family. Old World monkey genera include baboons, macaques, and mabahlls. Common names for other Old World monkeys include the talapoin, guenon, colobus, douc, vervet, gelada, mangabey, langur, mandrill, surili (Presbytis), patas, and proboscis monkey. Phylogenetically, they are more closely related to apes than to New World monkeys. They diverged from a common ancestor of New World monkeys around 55 million years ago.

Rhesus macaque Species of Old World monkey

The rhesus macaque, colloquially rhesus monkey, is a species of Old World monkey. It is listed as least concern in the IUCN Red List of Threatened Species in view of its wide distribution, presumed large population, and its tolerance of a broad range of habitats. It is native to South, Central, and Southeast Asia and has the widest geographic range of all non-human primates, occupying a great diversity of altitudes and a great variety of habitats, from grasslands to arid and forested areas, but also close to human settlements.

Barbary macaque Species of Old World monkey

The Barbary macaque, also known as Barbary ape or magot, is a macaque species native to the Atlas Mountains of Algeria and Morocco along with a small population of uncertain origin in Gibraltar. It is one of the best-known Old World monkey species.

Japanese macaque The only nonhuman primate in Japan

The Japanese macaque, also known as the snow monkey, is a terrestrial Old World monkey species that is native to Japan. They get their name "snow monkey" because some live in areas where snow covers the ground for months each year – no other non-human primate is more northern-living, nor lives in a colder climate. Individuals have brownish grey fur, pinkish-red faces, and short tails. Two subspecies are known.

Mentawai Islands Regency Regency in West Sumatra, Indonesia

The Mentawai Islands Regency are a chain of about seventy islands and islets approximately 150 kilometres off the western coast of Sumatra in Indonesia. They cover 6,011.35 sq2 and had a population of 76,173 at the 2010 Census and 85,156 at the 2015 Census; the latest official estimate is 92,021. Siberut at 3,838.25 square kilometres is the largest of the islands. The other major islands are Sipura, North Pagai and South Pagai. The islands lie off the Sumatran coast, across the Mentawai Strait. The indigenous inhabitants of the islands are known as the Mentawai people. The Mentawai Islands have become a noted destination for surfing, with over 40 boats offering surf charters to international guests.

Celebes crested macaque Species of Old World monkey

The Celebes crested macaque, 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.

Arunachal macaque Species of Old World monkey

The Arunachal macaque is a macaque native to Arunachal Pradesh in North-east India. It is listed as Endangered on the IUCN Red List. It was scientifically described in 2005.

Pig-tailed langur Species of Old World monkey

The pig-tailed langur, monotypic in genus Simias, is a large Old World monkey, endemic to several small islands off the coast of Sumatra in Indonesia. Its face is black, its fur is blackish-brown and it has a relatively short tail. It is a diurnal species, feeding in small groups in the rainforest canopy on leaves, and to a lesser extent, fruit and berries. Little is known of its natural history, but it is heavily hunted, its populations have been declining rapidly and the International Union for Conservation of Nature has assessed its conservation status as being "critically endangered". It has been included on a list of the World's 25 Most Endangered Primates.

Toque macaque Species of Old World monkey

The toque macaque is a reddish-brown-coloured Old World monkey endemic to Sri Lanka, where it is known as the rilewa or rilawa, . Its name refers to the whorl of hair at the crown of the head, compared to a brimless toque cap.

Assam macaque Species of Old World monkey

The Assam macaque or Assamese macaque is a macaque of the Old World monkey family native to South and Southeast Asia. Since 2008, the species has been listed as "near threatened" by the IUCN, as it is experiencing significant declines due to hunting, habitat degradation, and fragmentation.

Formosan rock macaque Species of Old World monkey

The Formosan rock macaque, also known as the Formosan rock monkey or Taiwanese macaque, is a macaque endemic to the island of Taiwan, which has also been introduced to Japan. Besides humans, Formosan rock macaques are the only native primates living in Taiwan. The species was first described by Robert Swinhoe in 1862.

Stump-tailed macaque Species of Old World monkey

The stump-tailed macaque, also called the bear macaque, is a species of macaque found in South Asia. In India, it is found in south of the Brahmaputra River, in the northeastern part of the country. Its range in India extends from Assam and Meghalaya to eastern Arunachal Pradesh, Nagaland, Manipur, Mizoram and Tripura.

Nicobar long-tailed macaque Subspecies of Old World monkey

The Nicobar long-tailed macaque is a subspecies of the crab-eating macaque, endemic to the Nicobar Islands in the Bay of Bengal. This primate is found on three of the Nicobar Islands—Great Nicobar, Little Nicobar and Katchal—in biome regions consisting of tropical and subtropical moist broadleaf forests.

The Mentawai macaques or Mentawai island macaques are two allopatric species of macaques that until recently were considered conspecific:

Southern pig-tailed macaque Species of mammal

The southern pig-tailed macaque, also known as the Sundaland pig-tailed macaque and Sunda pig-tailed macaque, is a medium-sized macaque that lives in southern Thailand, Malaysia, and Indonesia. It is known locally as the beruk.

Common treeshrew

The common treeshrew is a small mammal in the treeshrew family Tupaiidae, and is native to Thailand, Malaysia, and Indonesia. It has been listed as Least Concern by IUCN as it remains common and displays some adaptability to ongoing habitat loss.

Siberut macaque Species of Old World monkey

The Siberut macaque is a vulnerable species of macaque, which is endemic to Siberut Island in Indonesia. It was formerly considered conspecific with the Pagai Island macaque which is overall paler in color, but this arrangement was polyphyletic. Both were formerly considered subspecies of the southern pig-tailed macaque.

Tibetan macaque Species of Old World monkey

The Tibetan macaque, also known as the Chinese stump-tailed macaque or Milne-Edwards' macaque, is a macaque species found from eastern Tibet east to Guangdong and north to Shaanxi in China. It has also been reported from northeastern India. This species lives in subtropical forests at elevations from 800 to 2,500 m above sea level.

Red-tailed monkey Species of Old World monkey

The red-tailed monkey, also known as the black-cheeked white-nosed monkey, red-tailed guenon, redtail monkey, or Schmidt's guenon is a species of primate in the family Cercopithecidae.


  1. 1 2 Groves, C. P. (2005). Wilson, D. E.; Reeder, D. M. (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Baltimore: Johns Hopkins University Press. ISBN   0-801-88221-4. OCLC   62265494.
  2. Whittaker, D. & Mittermeier, R. A. (2008). "Macaca pagensis". IUCN Red List of Threatened Species . 2008: e.T39794A10258510. doi: 10.2305/IUCN.UK.2008.RLTS.T39794A10258510.en .
  3. Roos, C., T. Zieglerb, J. K. Hodgesb, H. Zischlera, and C. Abegg. 2003. Molecular phylogeny of Mentawai macaques: taxonomic and biogeographic implications. Molecular Phylogenetics and Evolution 29(1): 139-150.