Pygmy hippopotamus Pygmy hippopotamus The pygmy hippopotamus ("Choeropsis liberiensis" or "Hexaprotodon liberiensis") is a small hippopotamid which is native to the forests and swamps of West Africa, primarily in Liberia, with small populations in Sierra Leone, Guinea, and Ivory Coast. The pygmy hippo is reclusive and nocturnal. It is one of only two extant species in the family Hippopotamidae, the other being its much larger relative, the common hippopotamus ("Hippopotamus amphibius") or Nile hippopotamus. The pygmy hippopotamus displays many terrestrial adaptations, but like the hippo, it is semiaquatic and relies on water to keep its skin moist and its body temperature cool.
Common species species. Common species are frequently regarded as being at low risk of extinction simply because they exist in large numbers, and hence their conservation status is often overlooked. While this is broadly logical, there are several cases of once common species being driven to extinction such as the passenger pigeon and the Rocky Mountain locust, which numbered in the billions and trillions respectively before their demise. Moreover, a small proportional decline in a common species results in the loss of a large number of individuals, and the contribution to ecosystem function that those individuals represented. A recent paper argued that