Stump-tailed Macaques
By Breanne Cyr, Primates Incorporated Volunteer
Physical Characteristics
As its name implies, the stump-tailed macaque, otherwise known as the “bear macaque” or “Macaca arctoides,” get its name from its short tail and thick, dark brown hair (1,2,4). Its tail is hairless and only measures between 0.12 and 2.7 inches (1). Its face is also hairless and is pink or red. However, with exposure to the sun over the years, its face eventually darkens to brown or black (1,2,4). Additionally, with age, both males and females exhibit balding that starts at the forehead and goes toward the back of the head – a pattern that is similar to balding in male humans (1,2). Males are larger than females (about 22 lbs vs. 18 lbs), and have larger canine teeth that they use to show dominance within their group (1).
Geography and Habitat
Stump-tailed macaques are native to wet evergreen forests and rainforests of southeast Asia. They are found in northeastern India, southern China, West Malaysia, Thailand, Vietnam, and the Malay Peninsula (1,3). They are not found in dry forests, except for a population living in the Himalayan region of India (1).
Despite living in forests, stump-tailed macaques spend most of their day on the ground. They are not very agile in trees, but will climb them in order to sleep, get food, or escape from predators. Unlike some species of macaques, the stump-tailed macaque is not known to swim (1).
Behavior / Ecology
Stump-tailed macaques live in groups of up to 60 members (2). They maintain a dominance hierarchy where fights do occur, but they often reconcile after a conflict (4). The stump-tailed macaque is considered more peaceful and egalitarian than other macaque species (2).
Starting early in the day, stump-tailed macaques travel and forage until midday when they rest in the shade. During this time, they often groom one another and the young ones play. In the late afternoon, they forage again and travel to their sleeping site – usually in large trees or cliffs (1). They eat mostly fruit, but also eat seeds, flowers, roots, leaves, insects, and animals such as crabs, frogs, and birds (1,2). They also raid crops such as corn (1), potatoes, and rice (3). Like other macaques, stump-tailed macaques have cheek pouches to store food in, and can store up to the volume of their stomach (2).
Predators of the stump-tailed macaque include large raptors, leopards and dogs. To avert such predators, stump-tailed macaques shake branches, bare their canines, and take on an aggressive posture (1,2).
Conservation
According to the IUCN list, stump-tailed macaques are considered vulnerable, which means they are at risk for extinction in the near future (2,3). Most of this decline in population is due to habitat loss as a result of logging and timber extraction, as well as from hunting. Local people hunt stump-tail macaques for food, sport, and traditional medicine (3). The population of stump-tailed macaques has decreased 20% in the last 10 years (2), and is expected to decrease another 30% in the next 30 years (3). Within it’s geographic range, there are areas where the stump-tailed macaque has completely disappeared. Fortunately, some stump-tailed macaques reside within protected lands and are protected under national wildlife acts (3).
In Research
Because they bald similar to humans, stump-tailed macaques have been used to develop treatments for balding (1,2). Minoxidil, more commonly known as Rogaine, was originally developed to treat high blood pressure, but had a side effect of producing excessive hair growth. Thus, Rogaine was tested on stump-tailed macaques and found to be safe to be used for hair regrowth (1).
Sources:
- Cawthon Lang KA. 2005 October 4. Primate Factsheets: Stump-tailed macaque (Macaca arctoides) Taxonomy, Morphology, & Ecology. http://pin.primate.wisc.edu/factsheets/entry/stump-tailed_macaque. Accessed 16 April 2016.
- Erfurth, C. 2008. “Macaca arctoides” (On-line) Animal Diversity Web. http://animaldiversity.org/accounts/Macaca_arctoides/. Accessed April 16, 2016.
- Htun, S., Timmins, R.J., Boonratana, R. & Das, J. 2008.Macaca arctoides. The IUCN Red List of Threatened Species 2008: e.T12548A3354519. http://dx.doi.org/10.2305/IUCN.UK.2008.RLTS.T12548A3354519.en. Accessed 16 April 2016.
- “Stump-tailed macaque(Macaca arctoides)” Wildscreen Arkive. http://www.arkive.org/stump-tailed-macaque/macaca-arctoides/. Accessed 14 April 2016.
Map image: http://pin.primate.wisc.edu/fs/popup.php?type=map&img=macaca_arctoides
Stump-tailed macaque photo: http://pin.primate.wisc.edu/factsheets/entry/stump-tailed_macaque