Macaca nemestrina (Linnaeus, 1766)

Sexual Dimorphism Size Difference

Like other species in the Macaca genus, male Macaca nemestrina are larger than females.

Body Size and Weight

Males measure 50–58 cm (20–23 in) in length and weigh 5–12 kg (11–26 lb), while females measure 38–48 cm (15–19 in) in length and weigh 4.5–6 kg (9.9–13.2 lb).

Fur Coloration

This macaque has buff-brown fur, with a darker dorsal region and lighter ventral region.

Common Name Origin

Its common name comes from its short semi-erect tail, which resembles a pig’s tail.

Habitat Range

This macaque mostly inhabits rainforests up to 2,000 metres (6,600 ft) in elevation, and it will also enter plantations and gardens.

Geographic Distribution

Its range covers the southern half of the Malay Peninsula (only just extending into southernmost Thailand), Borneo, Sumatra, and Bangka Island.

Historical Singapore Presence

There are reports that this species was present in Singapore before 1950, but these individuals were likely escaped pets.

Current Singapore Population

All pig-tailed macaques currently in Singapore are introduced individuals.

Locomotion Habits

M. nemestrina is primarily terrestrial, but it is also a skilled climber.

Water Behavior

Unlike almost all primates, these macaques enjoy water.

Social Group Structure

They live in large social groups that split into smaller groups during daytime foraging.

Diet Composition

They are omnivorous, and their diet consists mainly of fruits, seeds, berries, cereals, fungi, and invertebrates.

Seed Dispersal Role

A study conducted in peninsular Malaysia found that this species is the primary, and possibly the only, seed disperser for the rattan species Calamus calicarpus (syn. Daemonorops calicarpa) and Calamus castaneus.

Social Hierarchy Basis

This species has social hierarchies: male hierarchy is based on strength, while female hierarchy is based on heredity.

Female Hierarchy Structure

Because of this hereditary hierarchy, the daughter of the alpha female ranks immediately above all other females in the group.

Group Leadership Roles

The alpha female leads the group, while males primarily manage internal group conflict and defend the group.

Gestation Period

Female gestation lasts approximately 5.7 months.

Reproductive Rate

Females give birth to a single infant every two years.

Development Timeline

Young are weaned at 4–5 months of age, and reach sexual maturity at 3–5 years of age.

Human Use

In Thailand, people have trained this species to harvest coconuts for 400 years.