The White Rhinoceros or Square-lipped rhinoceros (Ceratotherium simum) is one of the five species of rhinoceros that still exist. It has a wide mouth used for grazing and is the most social of all rhino species. The White Rhino consists of two subspecies: the Southern White Rhino, with an estimated 17,460 wild-living animals at the end of 2007 (IUCN 2008), and the much rarer Northern White Rhino. The northern subspecies has very few remaining, all in captivity. White Rhinoceroses are found in grassland and savanna habitat. Herbivore grazers that eat grass, preferring the shortest grains, the White Rhinoceros is one of the largest pure grazers. It drinks twice a day if water is available, but if conditions are dry it can live four or five days without water. It spends about half of the day eating, one third resting, and the rest of the day doing various other things. White Rhinoceroses, like all species of rhinoceros, love wallowing in mud holes to cool down.
White Rhinoceroses produce sounds which include a panting contact call, grunts and snorts during courtship, squeals of distress, and deep bellows or growls when threatened. Threat displays (in males mostly) include wiping its horn on the ground and a head-low posture with ears back, combined with snarl threats and shrieking if attacked. The White Rhinoceros is quick and agile and can run 50 km/h (31 mph).
White Rhinoceroses live in crashes or herds of up to 14 animals (usually mostly female). Sub-adult males will congregate, often in association with an adult female. Most adult bulls are solitary. Dominant bulls mark their territory with excrement and urine. The dung is laid in well defined piles. It may have 20 to 30 of these piles to alert passing rhinoceroses that it is his territory. Another way of marking their territory is wiping their horns on bushes or the ground and scrapes with its feet before urine spraying. They do this around 10 times an hour while patrolling territory. The same ritual as urine marking except without spraying is also commonly used. The territorial male will scrape-mark every 30 m (98 ft) or so around its territory boundary. Subordinate males do not mark territory. The most serious fights break out over mating rights to do with a female. Female territory is overlapped extensively and they do not defend it.