Description

The White Rhinoceros is the world's largest land mammal after the three species of elephant. It has a massive body and large head, a short neck and broad chest. The head and body length is 3.4 to 4.2 m (11 to 14 ft), with the tail adding another 50 to 70 cm (20 to 28 in). Shoulder height is 1.5 to 1.9 m (4 ft 10 in to 6 ft 3 in). Weight typically ranges from 1,360 to 3,630 kg (3,000 to 8,000 lb), with the male being slightly heavier. The largest recorded White Rhinoceros was about 4,530 kg (10,000 lb).

On its snout it has two horn-like growths, one behind the other. These are made of solid keratin, in which they differ from the horns of bovids (cattle and their relatives), which are keratin with a bony core, and deer antlers, which are solid bone. The front horn is larger and averages 90 cm (35 in) in length, reaching as much as 150 cm (59 in). The White Rhinoceros also has a noticeable hump on the back of its neck. Each of the four stumpy feet has three toes.
 
The colour of the body ranges from yellowish brown to slate grey. Its only hair is the ear fringes and tail bristles. White Rhinos have a distinctive broad, straight mouth which is used for grazing. Its ears can move independently to pick up sounds but it depends most of all on smell. The olfactory passages which are responsible for smell are larger than their entire brain.

Behavior and ecology

White Rhinoceroses are found in grassland and savannah 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 mudholes 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 his 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 over a female. Female territory is overlapped extensively and they do not defend it.

Reproduction

Females reach sexual maturity at 6–7 years of age while males reach sexual maturity between 10–12 years of age. Courtship is often a difficult affair. The male stays beyond the point where the female acts aggressively and will give out a call when approaching her. The male chases and or blocks the way of the female while squealing or wailing loudly if the female tries to leave his territory. When ready to mate the female curls its tail and gets into a stiff stance during the half hour copulation. Breeding pairs stay together between 5–20 days before they part their separate ways. Gestation occurs around 16–18 months. A single calf is born and usually weighs between 40 and 65 kg (88 and 140 lb). Calves are unsteady for their first 2 to 3 days of life. When threatened the baby will run in front of the mother, who is very protective of her calf and will fight for it vigorously. Weaning starts at 2 months and may continue suckling for over 12 months.

The birth interval for the White Rhino is between 2 and 3 years. Before giving birth the mother will chase off her current calf. White Rhinos can live to be up to 40–50 years old. Adult White Rhinos have no natural predators due to their size, and even young rhinos are rarely attacked due to the mother's presence or preyed on due its tough skin.

source : Wikipedia, the free encyclopedia