Water chevrotains are, except for during the mating season, solitary animals (3), with females inhabiting isolated home ranges and male ranges overlapping those of at least two females (2). Ranges are marked with faeces impregnated with anal gland secretions, and urine (3). Shy and secretive animals, water chevrotains are mostly active at night and are never found without the protection of dense cover in the day (2) (3). Their small size makes them fairly easy prey for a number of predators; when threatened the chevrotain either stands motionless amongst vegetation, or can dive into water (2). As its name suggests, it is capable in water, but can only swim for short periods before tiring (2) (3). Fallen fruits, such as figs, palm nuts and breadfruit make up the majority of the water chevrotain's diet, although it has also been known to feed on insects, crabs, scavenged meat and fish. It relies on its sense of smell to locate food (2), and being ruminants, they have a gut modified to ferment the food (3) A single young is born each year after a gestation of around four months. The young chevrotain lies up for the first three months of its life, receiving frequent nourishment from its mother's milk during periodic visits (2). At around nine months, the young are weaned and disperse from their mother's range. While water chevrotains are believed to be able to live for up to 13 years, few survive beyond eight years of age (2).

Chevrotains, also known as mouse deer, are the intermediates in appearance between pigs and deer (3). The water chevrotain has, like the other three chevrotain species, a compact body with a short, thick neck and small, narrow head. The limbs appear short and thin in relation to its bulky body, and its feet resemble miniature pig's trotters. The sleek coat of the water chevrotain is reddish-brown marked with distinctive white streaks and bold spots, and the tail reveals a vivid white underside when raised. Dense, thick skin on the rump and throat protect it from bites from the sharp canines of other water chevrotains (2); the canine teeth of the male are long and protrude outside the mouth, while those of the female are more peg-like. Male water chevrotains are smaller than females, weighing about 20 percent less (3).

Endemic to West and Central Africa, ranging across the forest belt from Sierra Leone and south-eastern Guinea, through Liberia, southern Côte d’Ivoire into south-west Ghana. Then ranges in southern Nigeria, east of the Niger River, through the central forest block, across southern Cameroon, Gabon, Cabinda (Angola), Congo and DR Congo to extreme western Uganda, where now believed extirpated (East 1999; Hart in press). A record from Angola's Lunda Norte Province, near the Cassai River, is the southernmost record of the species from the continent (Crawford-Cabral and Veríssimo 2005).

The African chevrotain, also known as the water chevrotain, is endemic to tropical regions of the African continent. While its range is primarily restricted to coastal regions, this species occurs from Sierra Leone to western Uganda.

(Robin 1990, Nowak 1999)

Biogeographic Regions: ethiopian (Native )

Occurs in western and central Africa rain forests, from Guinea to Gabon, and east to western Uganda (2) (4).

The water chevrotain is a small animal that resembles a deer (Cervidae). This species is larger than its Asian counterparts, maintaining a size similar to a rabbit. The water chevrotain has a body length of between 45 and 85 cm and a tail length ranging from 7.5 to 17 cm. Animals of this species weigh 7-15 kg, however, the average weight for males is only 9.7 kg, whereas females average 12 kg. The weight at birth is unknown.

Hyemoschus aquaticus has a small, pointed head and a stocky body set on slender, delicate legs. The rear of the body is wedge-shaped and slightly raised relative to the rest of the body. Neither sex has antlers, but males of the species have well developed sharp tusks that extend below the lips of the animal.

The pelage has stripes and spots that camouflage the animal within the shaded areas of the forest. The water chevrotain has white stripes on its head and neck and a white underside to its tail. It has large eyes, slit-like nostrils and medium-sized ears.

(Robin 1990, Nowak 1999)

Range mass: 7 to 15 kg.

Average mass: 9.7-12 kg.

Range length: 45 to 85 cm.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: female larger; ornamentation

Habitat and Ecology

Systems

• Terrestrial
• Freshwater

The African chevrotain can be found in tropical rain forests and thickets rarely more than 250 m away from water. At night, chevrotains can be observed in exposed clearings and open river banks but during the day, the animal cannot be found outside of the dense forest.

(Robin 1990, Kingdon 1979)

Terrestrial Biomes: rainforest ; scrub forest

The water chevrotain inhabits river valleys within lowland rainforest, along the edges of swamps and streams (2), usually within 250 metres of freshwater (5).

This species is primarily herbivorous, feeding on the leaves, fruits, and buds of trees and shrubs. It has occasionally been observed eating insects, crustaceans and even small mammals. Like many herbivores, the water chevrotain has various adaptations to facilitate effective digestion of its low-nutrient diet. Chevrotains are considered to be true ruminants, with a 4-chambered ruminating stomach.

(Robin 1990, Dubost 1984)

Average lifespan

Status: wild: 13.0 years.

Average lifespan

Status: wild: 14.0 years.

Observations: Little is known about the longevity of these animals. It has been suggested that they live up to 14 years in the wild (David Macdonald 1985).

When a female enters estrus, she is courted by the male who follows her movements and makes vocalizations. The cry of the male stops the female's movement, at which point the male licks her genital area. This pattern is repeated over some time. The male mounts the female by laying his body over hers and copulation takes place.

The gestation period is 6 to 9 months, and females give birth to one young a year. Due to the presence of four mammae in the females of this species, researchers suggest that they are capable of larger litters. Water chevrotains give birth to precocial young, capable of standing within an hour after birth. Females spend most of their day apart from their young and meet only to suckle them. Lactation lasts 3-6 months and the young disperse from the mother's home range when they reach sexual maturity (between 9 and 26 months).

(Nowak 1999, Kingdon 1979)

Average gestation period: 175 days.

Average number of offspring: 1.25.

Average age at sexual or reproductive maturity (male)

Sex: male: 403 days.

Average age at sexual or reproductive maturity (female)

Sex: female: 403 days.

Overall numbers of this species are currently decreasing due to hunting by humans and habitat destruction for timber resources. It is unlikely that this species will survive the habitat destruction it currently faces. This species is classified as near threatened by the IUCN and the species is also listed under appendix III of CITES in Ghana.

(Kingdon 1979, Grubb 1993)

CITES: appendix iii

IUCN Red List of Threatened Species: least concern

Classified as Data Deficient (DD) on the IUCN Red List 2007 (1).

Population

Population Trend

Major Threats

Hunting has reduced numbers of the water chevrotain in many parts of its range (2), particularly in Gabon where it is hunted intensively by local people for food (5). The water chevrotain is also known to be affected by human disturbance, such as expanding agriculture, and animals leaving disturbed areas are unlikely to survive (2).

Conservation Actions

A Conservation Action Plan for deer species was published by the World Conservation Union (IUCN) Deer Specialist Group in 1998. The primary measure outlined for the water chevrotain was to undertake further research to determine the species' status in the wild (5). The water chevrotain is also known to occur in a number of protected areas, such as Okapi Faunal Reserve in the Democratic Republic of Congo (6). However, protecting the water chevrotain from the significant threat of bushmeat hunting is unlikely to occur through these measures alone; it is a complex issue requiring a diversity of approaches, including education, the implementation and enforcement of laws, and anti-poaching operations (7).

H. aquaticus occupies tropical rain forests which are utilized by humans as a source of timber. Although currently classifies as near threatened, the protection of this species could cause negative economic effects to timber harvesters.

(Robin 1990)

The water chevrotain is avidly hunted by humans.  (Nowak 1999)