The White rhinoceros or square-lipped rhinoceros (Ceratotherium simum), is the largest extant species of rhinoceros. It has a wide mouth used for grazing and is the most social of all rhino species. The white rhinoceros consists of two subspecies: the southern white rhinoceros, with an estimated 17,460 wild-living animals at the end of 2007 (IUCN 2008), and the much rarer northern white rhinoceros. The northern subspecies has very few remaining, with only five confirmed individuals left (four females and one male), all in captivity.