Rhinoceroses: Rhinocerotidae

Physical characteristics: This is the largest rhino species. Males can weigh up to 5,000 pounds (2,300 kilograms), while females weigh around 3,800 pounds (1,700 kilograms). Males measure to 150 inches (380 centimeters) in length, females to 135 inches (343 centimeters). The body is covered sparingly with short hairs, and the hide is gray. The horn closest to the snout measures 20 to 62 inches (50 to 158 centimeters. The other horn is no longer than 15 inches (40 centimeters). Both sexes have horns.

Geographic range: In the nineteenth century, the white rhino was found in two separate regions of Africa: southern Chad, Central African Republic, southwest Sudan, northeast Democratic Republic of the Congo, and northwest Uganda; and southeast Angola, parts of

White rhinos live in groups of one dominant male, females and their offspring, and some young males. (Photograph by Harald Schütz. Reproduced by permission.)

Mozambique, Botswana, Zimbabwe, Namibia, and northeast South Africa. Today the white rhino occupies fragments of these areas and is restricted to game preservations and national parks.

Habitat: The white rhinoceros prefers the drier savanna regions in southern Africa, yet prefers the moist savanna in the northern range.

Diet: The southern white rhino eats grasses and also ingests herbs and occasionally woody shrubs. Short grasses are the preferred food year-round, though later in the dry season, interest turns to some of the taller grasses. The northern rhino prefers short grasses but includes medium-tall grasses in its foraging.

Behavior and reproduction: White rhinos seem to be the most complex species of the family. Their range varies in size from less than 1 square mile (less than 1 square kilometer) to 5 square miles (8 square kilometers). They spend their entire lives within these ranges, and live in small groups with one dominant male, numerous females and their offspring, and even some sub-adult males. Fighting is rare. Lions have been reported to prey on young calves, but that is the extent of natural predators.

Gestation lasts sixteen months, at which time the female seeks a quiet place to birth her single calf. Calves nurse until the age of fifteen to twenty-four months, though they begin eating vegetation after a couple months of age. Females are sexually mature between the ages of six and eight years while males begin breeding around ten to twelve years. White rhinos live no longer than about forty years in the wild.

White rhinoceroses and people: White rhinos are terrified of humans. Early European hunters brought the white rhino to near extinction as they harvested populations for their meat and other body parts. The southern population has recovered well, but the future of the northern species is questionable at best.

Conservation status: The white rhino is listed as Near Threatened by the IUCN because even though population levels are higher than other rhino species, this breed is easy to track down and hunt, so reintroduced herds have been easily eliminated. The horn of the white rhino is particularly valuable, fetching a couple thousand dollars per horn on the black market. Recently, a herd of young male elephants killed a number of white rhinos. This is normally highly unlikely, but these particular elephants were orphaned at a young age and had no older bulls in the herd. Once older bulls were introduced, the aggression of the younger elephants subsided, demonstrating the importance of hierarchy in elephant populations. ∎