Macaca arctoides (I.Geoffroy Saint-Hilaire, 1831)

Scientific Name

The stump-tailed macaque, with the scientific name Macaca arctoides (I.Geoffroy Saint-Hilaire, 1831), has the following characteristics.

Adult Fur & Tail

It has long, thick, dark brown fur, a hairless face, and a short tail that measures between 32 and 69 mm (1.3 and 2.7 in).

Cheek Pouches

It has cheek pouches that it uses to store food for short periods of time.

Infant Coloration

Infants are born white and darken in fur color as they mature.

Facial Aging Changes

As the macaques age, their bright pink or red faces darken to brown or nearly black and lose most of their hair.

Sexual Size Dimorphism

Males are larger than females: males measure 51.7–65 cm (20.4–25.6 in) long and weigh 9.7–10.2 kg (21–22 lb), while females measure 48.5–58.5 cm (19.1–23.0 in) long and weigh 7.5–9.1 kg (17–20 lb).

Canine Teeth Dimorphism

Male canine teeth, which are important for establishing dominance within social groups, are more elongated than female canine teeth.

Geographic Range

For distribution and habitat, the stump-tailed macaque ranges from northeastern India, Myanmar, Thailand, and the northwest tip of Peninsular Malaysia to Laos, Cambodia, Vietnam, and southern China.

Native Habitat

It lives in evergreen, tropical, and subtropical moist broadleaf forests at elevations up to 4,000 m (13,000 ft).

Habitat Requirements

It relies on rainforests for food and shelter, and only enters secondary forests if those forests border old-growth tropical forests.

Bangladesh Population Status

The species is possibly extinct in Bangladesh.

Cambodia Population

In Cambodia, a population of 230 individuals has been reported in Keo Seima Wildlife Sanctuary.

Introduced Mexican Population

A study population was introduced to Tanaxpillo, an uninhabited island in Lake Catemaco, Veracruz, Mexico in 1974, where the population lives under seminatural conditions.

Study Population Basis

Most scientific information about this species comes from the introduced population on Tanaxpillo and other captive settings, because few long-term studies have been conducted on wild stump-tailed macaques.

General Social Structure

For behaviour and ecology, stump-tailed macaques generally share the typical social structure of other macaque species.

Dominance Hierarchy

They have a linear dominance hierarchy that is hereditary among females, but fluctuates among males based on fighting ability and social maneuvering.

Conflict Behavior

Compared to rhesus macaques and long-tailed macaques, stump-tailed macaques defuse intense confrontations, are relatively tolerant of their group members, and have a surprisingly large repertoire of reconciliation tactics.

Female Reproductive Hormones

For reproduction, research on a study population found that female stump-tailed macaques have increased levels of steroid sex hormones, specifically 17β-estradiol and progesterone.

Hormone Seasonal Patterns

17β-estradiol levels are significantly higher during summer and fall, while progesterone levels are significantly higher during summer, fall, and winter.

Mating Seasons

This pattern explains why stump-tailed macaques have two mating seasons each year: one in summer (July–August) and one in fall (November).

Birth Frequency Support

This finding is supported by the distribution of birth frequency in the species.