The pygmy hippopotamus, scientifically known as Choeropsis liberiensis or Hexaprotodon liberiensis, is a large mammal living in swamps and forests and are one of the two remaining species of Hippopotamidae family. The name Pygmy is given to them due to their smaller size than other river Hippos. They are native to western Africa. Their species name comes from the place where their vast majority lived, i.e. Liberia. Formerly, Hippopotami were believed to be most closely related to pigs but, recent studies performed on genes have revealed that their closest living relatives are in fact whales. The earliest known hippopotami are believed to have evolved in Africa around 16 million years ago.
The Pygmy hippos have the same appearance as a hippopotamus. The large muscular body is supported by four big legs. It is however smaller in size than the hippopotamus; weighing 180-270 kg, one fourth of its larger cousin. It stands about 75-83 cm up to shoulder and body length is 150-177 cm from head to tail. Their skin color is typically greenish-black, with a thin epidermis over a several cm thick dermis. Average lifespan of this species is about 30-55 years. One major difference between common hippo and the Pygmy hippo is that, in case of common hippo the back is parallel to the ground and in case of Pygmy it is sloped forward.
As the Pygmy hippos are one of the rare nocturnal forest animals, it is very difficult to study their behavior in the wild. According to World conservation union, there are around 3,000 Pygmy hippos living in the wild. The greatest threat to their population is the loss of habitat. Often they are observed to be hunted by the bush hunters for their meat, which is of excellent quality. Because of their reclusive behavior, these animals have no known predators. The pygmy hippopotamus is classified as vulnerable species.