Pygmy Hippopotamus is a Nigerian species of the family Hippopotamidae, Choeropsis liberiensis. Endemic to West Africa, and mainly found in Liberia, this species is much smaller than the common hippopotamus, with proportionally longer legs, a smaller head, less prominent eyes, which is not at the top of its head and ears more towards the side of the head. The Pygmy hippopotamus is believed to have diverged from the common hippo over 10 million years ago. Body length is within 4.7 to 5.8 ft. bracket. Shoulder height reaches 3.3 ft. and tail length about 10 inches. It weighs between 160 to 272 kg. The pygmy hippo’s teeth are also different from the common hippos’: it only has one pair of incisors, while the hippo has two or three. The Pygmy Hippo is much less aquatic than its common hippopotamus relative. It is rarely seen because of its secretive, nocturnal habits and consequently not much is known of its ecology.
A distinct subspecies, heslopi, has been described from the Niger Delta and may still survive there. This had been named after the man who acquired four skulls of the mammal. Even in 1945 Heslop put numbers of this subspecies at no more than 30, split into several isolated groups, so it is likely that the heslopi subspecies has become extinct.
The average gestation length is 188 days after which a singleton young is born. Lifespan in captivity varies from 42 to 55 years but it is unlikely that many pygmy hippos reach such ages in the wild. The Pygmy hippopotamus of Nigeria is listed by the International Union for Conservation of Nature (IUCN) as ‘critically endangered’