Rhinoceroses: Rhinocerotidae

Physical characteristics: This is the smallest and oldest living rhino species, with a weight from 2,200 to 4,400 pounds (999 to 1,998 kilograms) and a shoulder height of 48 to 58 inches (120 to 150 centimeters). From head to tail, this species measures 100 to 125 inches (250 to 315 centimeters). The body is covered sparingly with short hairs, and the hide is dark red-brown. The horn closest to the snout can measure up to 31 inches (79 centimeters), but that is unusually long, and it is normally much shorter. The other horn is no longer than 6 inches (15 centimeters). Both sexes have horns.

A newborn Sumatran rhinoceros, born at the Cincinnati Zoo in 2001, is the first Sumatran rhinoceros to be born in captivity in 112 years. (AP/Wide World Photo/Cincinnati Zoo. Reproduced by permission.)

Geographic range: Though they once roamed over Southeast Asia, they are found only on the island of Sumatra and in the Malay peninsula today.

Habitat: The Sumatran rhino lives in mountainous rainforests today, but experts believe it may have once occupied lowland forests, as well. They need to live near permanent bodies of water.

Diet: This species eats mostly twigs and leaves of small trees and shrubs. It also enjoys fruits and herbs. Although these rhinos feed on undergrowth along streams, they will reach higher shoots and twigs by walking on plants and pressing down on the trunk of saplings with their round bodies.

Behavior and reproduction: Sumatran rhinos are solitary and come together only to breed, although calves and mothers are frequently seen together. They like to wallow in mud holes, which not only keep them cool, but also protect their thin outer layer of skin from insect bites and thorns. Males roam whereas females have home ranges covering 4 to 6 square miles (10 to 15 square kilometers). Each territory has a salt lick, which the rhinos visit frequently.

Pregnancy lasts 475 days and calves weigh around 72.8 pounds (33 kilograms). While nursing, females confine their movements to small areas close to a salt lick. Calves leave their mothers between sixteen and seventeen months, at which time the mother returns to her non-breeding range. Females give birth about every four years.

Sumatran rhinoceroses and people: The number of Sumatran rhinos has decreased by 50 percent in the past twelve years due to poaching. It is believed that as of 2002, there are fewer than three hundred left in existence. Captive breeding has not been successful, as it has come to light that rhinos have strange mating habits that captivity cannot allow.

Conservation status: Listed as Critically Endangered since 1996. ∎