The second largest terrestrial mammals following elephants, white rhinos stand at 5 to 6 feet (1.5 to 1.8 meters) in height, with males weighing as much as 5,070 pounds (2,300 kilograms). Females are significantly smaller, though still quite large, frequently reaching 4,000 pounds (1,800 kilograms) themselves. As a perissodactyl, white rhinos have an odd number of toes, as opposed to artiodactyl, species such as giraffes, sheep, and deer, which all have even-numbered toes. The most famous attribute of the white rhino, however, is their distinctive horns. Their front horns, on average, will generally reach 24 inches (60 centimeters) or longer, though some have been known to grow up to an astounding 60 inches (150 centimeters) in length.
As herbivores, white rhinos prefer to feed on short grasses in the African grasslands and savannahs. They have square upper lips which are specialized for grazing. Having adapted to their dry environments, white rhinos can live for several days without water. As odd-toed ungulates, white rhinos are in the same order as horses, zebras, and several other large grazing animals. Their stomachs are considered very simple compared to artiodactyls’ multi-chambered ones. However, they are hindgut fermenters, which means the presence of bacteria within their stomachs can break down fibrous matter via fermentation as a dietary energy source, making up for the simplicity of their stomachs. Hindgut fermenters’ "ceca", the areas connecting their small and large intestines, are enlarged, and therein are carried the bacteria which make white rhinos capable of digesting the cellulose from grasses they feed upon as it passes through their stomachs.
Habitat and Range
Residing in tropical and subtropical grasslands and savannahs, the northern white rhino is found in east-central Africa, while the southern white rhino is distributed across a large range encompassing much of southern Africa. The northern white rhino is listed as "Critically Endangered" by the IUCN's Red List, and they are possibly extinct in the wild, as there have not been any sightings of the last four wild rhinos since 2006. Furthermore, there are only three northern white rhinos left in captivity. Meanwhile, the southern white rhino is classified as a "Near Threatened" species, with their own numbers totaling more than 20,000. White rhinos suffer from urbanization and habitat destruction, but the biggest threat to these animals is poaching, which is prompted by the high prices their horns can fetch on the black market. The horns are used in native jewelry and spiritualistic medicine. Southern white rhinos are also found in a number of zoos and parks around the globe.
White rhinos are more social than black rhinos, and females and their young can often be seen living together in groups. Mature male white rhinos, however, are generally solitary creatures, and often display very territorial behaviors towards other bulls. While they may allow females and juvenile males into their territories, bulls will spread urine and feces around and damage plants with their horns to mark their boundaries to ward off encroachment by other bulls. Despite such attitudes towards fellow members of their own species, white rhinos are not known to be aggressive towards other species. This, unfortunately, makes them even more vulnerable to poachers. White rhinos are mostly active during the early mornings and late afternoons and evenings, in order to avoid the often stifling African savannah heat. When the heat becomes unbearable, they will cool themselves off, and ward off external parasites, by covering themselves in mud.
Female white rhinos can breed and birth throughout the year, though the peak breeding seasons occur in summer and autumn. White rhino courtship involves the male staying by a desired female for up to three weeks, tending her until copulation is finished. Once the mating is complete, the female will leave the bull’s territory. A white rhino’s gestation period is about 16 months, usually resulting in the birth of a single calf. A calf will stay with its mother for two to three years before the mother chases it off, at which time the mother will look to mate again. Sexually mature females will begin to mate when they are 6 or 7 years old, whereas males do not start mating until they are 10 to 12 years of age.