Hexaprotodon liberiensis
TAXONOMY
Hippopotamus minor (Morton, 1849), St. Paul's River, Liberia. Two subspecies, Hexaprotodon liberiensis liberiensis and H. l. heslopi, but the latter is most probably extinct.
OTHER COMMON NAMES
French: Hippopotame nain; German: Zwergflusspferd; Spanish: Hipopotamo enano.
PHYSICAL CHARACTERISTICS
Length 5–6 ft (1.5–1.8 m); weight 350–600 lb (159–272 kg). The pygmy hippo is similar to its larger cousin in its general body shape; its head, however, is proportionately smaller with less protuberant eyes, which, with the ears and nostrils, are not so high on the head. Its limbs and neck are relatively longer, and the back slopes forward instead of being parallel with the ground as in the common hippo. The skin is darker than that of the larger species—a blackish color. The dental formula is (I2/1, C1/1, P3/3, M3/3) × 2 = 34.
DISTRIBUTION
The pygmy hippo is confined to West Africa with Liberia containing the majority of the population. Other countries with pygmy hippos are Guinea, Ivory Coast, and Sierra Leone.
HABITAT
A forest animal that spends the day in or near water, usually a river or stream, which it leaves at night to forage. Some, at least, occupy burrows in the banks of rivers; it is not clear whether the hippo excavates the burrow itself or merely enlarges an existing hole.
BEHAVIOR
Its behavior in the wild is insufficiently known. It is usually found alone, although pairs occur. It is not clear whether the species is monogamous or promiscuous. It follows game trails and spreads its feces with its tail.
FEEDING ECOLOGY AND DIET
Feeds with its lips; its diet is varied, with fruits and ferns figuring prominently. Grass is readily eaten when available.
REPRODUCTIVE BIOLOGY
Polygamous. Copulates either on land or in the water after a consorting period; it is not known how long the pair bond persists. Estimates of the gestation period vary from 188 to 210 days. Births occur in water or on land, and singletons are the rule. Birth weights of 35 calves in Basel Zoo averaged 12.61 lb (5.73 kg). Sexual maturity in zoo specimens occurs between three and five years of age; it is probably later in the wild. The calf does not follow its mother when she is foraging, remaining in hiding and visited at intervals to be suckled.
CONSERVATION STATUS
Listed on Appendix I of CITES, and the IUCN lists it as Vulnerable to extinction, mainly through loss of habitat. It adapts well to captivity and breeds readily so that it could, if necessary, be maintained indefinitely in zoos.
SIGNIFICANCE TO HUMANS
Not normally a threat to human beings, although it is a formidable animal and can cause injury to hunters. It occasionally raids crops. It is the subject of much folklore.
