The Stump-tailed Macaque or Bear Macaque (Macaca arctoides) locally known as Beruk Kentoi in Malay is an Old-World Monkey native to Cambodia, southwestern China, northeastern India, Laos, Malaysia, Thailand, Myanmar, and Vietnam (Chetry et al., 2020). In Malaysia, this species is particularly known to inhabit the state of Perlis which is located in the northern region of Peninsular Malaysia (Syamil et al., 2019; Roos et al., 2014). The only protected area in Peninsular Malaysia where this species can be found is Wang Kelian in Perlis State Park (Jayaraj et al., 2013). This macaque can be found in the broadleaf evergreen forest of tropical and subtropical regions where it inhabits high areas up to 2,000 m in primary or secondary forest (Cawthon-Lang, 2005; Francis & Barrett, 2008).

Macaca arctoides has some special features that distinguish it from other Macaca species. The babies are born with white hair, and becomes darker as they grow older. This species has long, thick dark brown fur that cover their bodies, except for the tail and face. Its tail is shorter than other species of the genus Macaca, measuring between 32 to 69 mm long. Its face is bright pink or red which becomes darken to brown or almost black as this spesies get older and are exposed to sunlight (Cawthon-Lang, 2005). What is special about Beruk Kentoi is that as they grow older, this macaque species will experience hair loss to become partially bald which starts at the forehead and advance towards the middle of their head. This process is similar to the process of hair loss that occurs in males for humans, but the process experienced by this macaque is happening to both sexes, male and female species (Uno et al., 1967).

Furthermore, the male species of M. arctoides is larger than the female species, measuring between 517 to 650 mm in height while the female has an average height between 485 to 585 mm (Cawthon-Lang, 2005). The skull of a female is slightly smaller than a male. If viewed from the front angle of the female forehead bone is not wide and the forehead bone is smaller than the male species. Like all other macaques, M. arctoides also have sacs on their cheeks to store food for short periods of time (Cawthon-Lang, 2005).

M. arctoides mainly spend most of their time foraging and traveling on the ground, as they are not very agile on the trees. They are also known to occasionally climb trees in searching for foods. Adult males are more often found in a tall tree to guard and watch over the troop from any danger. If disturbed, the species usually escape on the ground and through the undergrowth, but occasionally may climb trees (Francis & Barrett, 2008; Fooden, 1990). Compared to other macaques, this species does not know how to swim (Fooden, 1990) and its lifespan is up to 30 years (Cawthon-Lang, 2005).

Typically, the Stumped-tailed macaque lives in relatively large multimale-multifemale social groups (consisting of more than one adult male and female) with troop size varies from 10 up to 60 individuals. Young males would leave their birth group at or before sexual maturity and immigrate into a new group, while the female would remain in the natal group (Fooden, 1990).

The Stumped-tailed macaque wakes up at about dawn, foraging throughout the morning, and stops a few hours before midday for rest and grooming. They continue searching for foods in the evening until sunset where they settled into their sleeping sites which usually be trees or cliffs (Cawthon-Lang, 2005; Fooden, 1990). Their daily estimated distances are between two to three kilometers. This species mainly feed on fruits and plant parts (Fooden, 1990; Sorenson, 2018; Osman et al., 2020). They also eat insects, freshwater crabs, birds, and bird's eggs when available (Fooden, 1990; Sorenson, 2018).

According to the IUCN Red List of Threatened Species, the Stumped-tailed macaque has been assessed as Vulnerable (VU). This species is becoming rare in Malaysia and neighboring Thailand. Globally, this species is regulated by CITES Appendix II (CITES, 2015) and also protected under Malaysia Wildlife Conservation Act 2010 (Act. 716). This macaque species is threatened due to hunting for food, trade, sport, and traditional medicine, habitat loss caused by logging, and infrastructure development. Thus, among the solutions to increase the populations of this species are by increasing education programs, highlighting the status of threatened species in these areas, and also implementation of better enforcement in forest protection and conservation.