Head and body length: 42.5-68 cm

Shoulder height: 30-35 cm

Tail length: 6-10 cm

Adult weight: 3.5-4.5 kg

A very small ungulate with a hunched posture and exceedingly slender legs. There is considerable variation in coloration among greater chevrotains, which has led to the description of numerous subspecies. In general, the pelage is orange-brown, with a grizzled appearance due to a black band on each hair. The extent of this black band (larger or smaller) results in some populations, particularly on smaller islands, that are very dark or very red. The underparts, from between the front legs to the underside of the tail, are white with a central dark stripe. The underside of the jaw is similarly white. Five white lines typically mark the throat; two extend from the edges of the jaw patch, and are paralleled by another pair of stripes lower on the throat. A fifth central stripe or wedge on the throat may or may not connect with these other stripes. The forehead tends to be dark, and black lines extend from around the eyes to the nose, contrasting with bright orange "eyebrow" stripes. Greater chevrotains do not grow horns or antlers, but males have enlarged upper canine teeth which protrude beyond the upper lip. Although these teeth grow continuously, they are usually 5-7 cm long as they often break. Both sexes possess a scent gland on the underside of the jaw.

Similar species

• The lesser Malayan chevrotain (Tragulus kanchil) is sometimes distinguished by its smaller size, although this in unreliable in the field and there is a general reduction in body size of greater chevrotain populations on small islands. Lesser chevrotains tend to be more uniform in color, and lack distinctive facial markings. The white throat markings of the lesser chevrotain typically have only three stripes.
• The Balabac chevrotain (Tragulus nigricans) was once thought to be a dark form of T. napu. It can be recognized by its very dark color and restricted range.

Gestation period: 152-155 days.

Litter size: Generally one.

Weaning: By three months of age.

Sexual maturity: As young as 4.5 months for females; males at 7 months.

Life span: Up to 14 years.

The greater chevrotain is a non-seasonal breeder; females in peninsular Malaysia give birth throughout the year. Females are able to conceive again within hours of giving birth; if conception does not occur, the estrus cycle is roughly 14 days in length. Neonates weigh 225-380g and are able to stand within 30 minutes of birth. Young are "tucked up" by their mothers in secluded areas and are visited for nursing. Female chevrotains have a distinctive posture for nursing, performed while standing and raising one hind leg. Adult size is reached at 5-6 months of age, and the tusk-like canines of young males are visible at 10 months.

In optimal habitat, greater chevrotains can occur at very high densities (37-312 individuals per square kilometer). Home ranges average 7 hectares in size in primary forest; in suboptimal habitats (such as logged forests), ranges are much larger, averaging 19 hectares. Camera-trapping surveys suggest that this species is active day and night, showing most activity between 04:00-10:00 and 16:00-00:00. Chevrotains are shy and reactive. When mildly alarmed by a strange noise, they will freeze in position (often with one leg raised) and observe until the danger has passed. When in this heightened alertness, the hind feet may be stamped to produce a drumming noise. If startled, these chevrotains flee with explosive speed. This species is a good swimmer and may retreat to water if threatened. The gland on the chin is used by both sexes to mark objects and other chevrotains, although males exhibit significantly more marking behavior than females. Vocalizations include a range of squeaks and an aggressive growl.

Family group: Generally solitary. Occasionally seen in pairs (male-female or female-juvenile) or rarely groups of three.

Diet: Primarily fruit.

Main Predators: Many large and medium-sized carnivores in its range.

Greater chevrotains are found in forested habitats of the southern Thai-Malay peninsula, Sumatra, Borneo, and numerous smaller Indonesian islands. The exact distribution has not been precisely determined due to a general lack of rigor in distinguishing the various species of Tragulus in the field. The species shows a preference for mature forests, although it will use secondary forests and plantations. The approximate range is depicted in the map below.

IUCN Red List: Least Concern (2015).

CITES Listing: Not listed (2019).

Threats: Hunting, habitat loss (timber harvesting).

The greater chevrotain is still widespread across its range, and is locally abundant in some regions. It appears to be resilient to hunting pressures, but may be more impacted by habitat disturbance than once thought. There are no estimates for total population, although the trend is thought to be a decline.