The white rhinoceros or square-lipped rhinoceros is one of the five species of rhinoceros.
It is found in Africa and has two subspecies, the southern white rhino, and the much rarer northern white rhino.
Almost at the edge of extinction in the early 20th century, the southern subspecies has made a tremendous comeback. Today, there are more than 21,000 animals in protected areas, private game reserves and zoos.
In the world, there are now only two northern white rhinos left: Najin, a female, was born in captivity in 1989 and Fatu, also a female, was born in captivity in 2000. They both belong to the Dvůr Králové Zoo in the Czech Republic, but live in Ol Pejeta Conservancy in Kenya, Africa.
White rhinoceroses are found in grassland and savannah habitat. They usually live near water sources because they generally consume water as often as twice a day.
White rhinoceros can live to be up to 50 years old.
The white rhinoceros is the largest species of rhinoceros. The head and body length is from 3.4 to 4 m (11.2 to 13.1 ft), with the tail adding another 70 cm (28 in) and the shoulder height is 160 to 186 cm (5.25 to 6.1 ft). The weigh is from 1,600 to 4,000 kg (3,500 to 8,800 lb). It is the only rhinoceros in which males are noticeably larger than females.
The color of the body ranges from yellowish brown to slate grey.
On its snout it has two horn-like growths, one behind the other. The front horn is larger and averages 60 cm (24 in) in length, reaching as much as 150 cm (59 in) but only in females.
It also has a noticeable hump on the back of its neck.
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 its sense of smell. The olfactory passages that are responsible for smell are larger than their entire brain. The white rhinoceros has the widest set of nostrils of any land-based animal.
These animals have 24 teeth.
White rhinos are diurnal, and most active during the day.
White rhinos eat short grass and some leaves. They are considered grazers, because they will eat constantly throughout the day, rather than having set meals.
White rhinos can go up to five days without drinking, because they get some moisture from the grass they eat.
The animal makes much use of shade trees for resting.
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.
Reproduction is a slow process for rhinos, since the mother will only carry one calf at a time. The gestation period of a white rhino is 16 months. A single calf is born and usually weighs between 40 and 65 kg (88 and 143 lb). It will survive solely on that rich milk for about a week, after which it will be introduced to soft grasses and foliage. It will continue to feed in this way for approximately 12 to 18 months, after which it is fully weaned.
The birth interval for the white rhino is between two and three years. Before giving birth, the mother will chase off her current calf.
Historically the major factor in the decline of white rhinos was uncontrolled hunting in the colonial era, but now poaching for their horn is the primary threat. The white rhino is particularly vulnerable to hunting, because it is a large and relatively unaggressive animal with very poor eye sight.
A popular albeit widely discredited theory of the origins of the name “white rhinoceros” is a mistranslation from Dutch to English. The English word “white” is said to have been derived by mistranslation of the Dutch word “wijd”, which means “wide” in English. The word “wide” refers to the width of the rhinoceros’s mouth. So early English-speaking settlers in South Africa misinterpreted the “wijd” for “white” and the rhino with the wide mouth ended up being called the white rhino and the other one, with the narrow pointed mouth, was called the black rhinoceros.
After the three species of elephant, it is the most massive remaining land animal in the world.
Their horns 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.