Rhinoceros, a huge animal of tropical Africa and Asia. There are five species of rhinoceroses. They range in height at the shoulder from 4 to 6 feet (1.4 to 2 m), and in weight from one to four tons (900 to 3,600 kg).

The rhinocerosThe rhinoceros has one or two horns, depending on the species.

The rhinoceros has a massive head and body; small ears with rounded tips; small eyes; short, stocky legs; and a short tail. There are three toes on each foot, each with a hooflike nail.

The skin of the rhinoceros is yellowish-brown to gray or black. It is thick and may be hairless or covered with coarse, bristly hair, depending on the species. In some species, the skin is arranged in folds resembling armor plates. The tail has a tuft of bristly hair at the tip.

Rhinoceroses are active in the early morning and in the evening, feeding on leaves, twigs, fruit, and grass. Some species have prehensile lips, which help them grasp food. During the day, rhinoceroses wallow in mud and take dust baths to relieve themselves of the irritation caused by the hordes of ticks that infest them. Cattle egrets and oxpeckers, also called tick birds, are often seen perched on the backs of rhinoceroses, feeding on the ticks. Their noisy scolding sounds an alarm when danger approaches.

The rhinoceros has poor vision but acute senses of smell and hearing. It is known for its unprovoked charges. The charges are believed to be the result of its poor eyesight, which causes it to panic at strange smells and sounds. During a charge, a rhinoceros can run as fast as 25 miles per hour (40 km/h).

The female typically bears a single calf. The calf nurses for about two years and stays with the mother for another year or two. Rhinoceroses mature at the age of five or six, and have a life span of up to 50 years.

Humans are the only enemies of adult rhinoceroses. (Young rhinoceroses are preyed on by lions and hyenas.) Once hunted as trophy animals, most species of rhinoceroses are now protected in game reserves. However, they are hunted illegally for their horns. The horns are ground into powder and used in folk medicine in China, Korea, and Japan, and are made into handles for ceremonial daggers in North Yemen. Due to such poaching, all five species of rhinoceroses are threatened with extinction.

What's Odd About a Rhino's Toes and Nose?

Most hoofed mammals have an even number of toes. But a rhinoceros has an odd number—three on each hoof. The middle toe is the largest. It is the main support for the rhino's heavy body. The rhino always walks on tiptoe.

A rhino has a fat body and short legs. You might think it couldn't run very fast. But a scared or angry rhino can run about 30 miles (48 kilometers) an hour.

A rhino's nose is also odd. The rhinoceros is the only animal with a horn on its nose. The horn may measure about 1 to 3 1/2 feet (30 to 107 centimeters) long. Some rhinos also have a second, shorter horn behind the first.