Rhinoceros, black

Diceros bicornis

phylum: Chordata

class: Mammalia

order: Perissodactyla

family: Rhinocerotidae

status: Critically endangered, IUCN Endangered, ESA

range: Angola, Botswana, Cameroon, Ethiopia, Kenya, Malawi, Mozambique, Namibia, Rwanda, South Africa, Swaziland, Tanzania, Zambia, Zimbabwe

Description and biology

The black rhinoceros is one of two species of rhinoceros found in Africa (the other is the white rhinoceros). Despite its name, the animal is actually gray in color. An average black rhinoceros has a head and body length of 9 to 12 feet (2.7 to 3.7 meters), stands 4.5 to 5.25 feet (1.4 to 1.6 meters) tall at its shoulder, and weighs between 2,000 and 4,000 pounds (908 and 1,816 kilograms). The animal's huge size is deceiving, as it can move quite quickly when it decides to charge. It has very poor eyesight—it can see clearly only up to 30 feet (9 meters) away—but acute senses of hearing and smell.

Rhinoceros means "horn nosed." The black rhinoceros has two horns on its snout. The front one is longer and can measure up to 53 inches (135 centimeters). The animal uses its horns (made of keratin fibers, the same substance as in human

fingernails) to dig in the ground for mineral salt, to defend its territory against other rhinos, and to defend itself against predators such as lions and hyenas.

The black rhinoceros protects itself against the intense African heat by sleeping during the day in a patch of brush. It awakens in the cool of the evening to begin feeding. The animal is an herbivore (plant-eater), eating branches, leaves, and bark. Its pointed upper lip is prehensile, meaning the lip can actually grasp branches to help pull and break them.

Black rhinos are mostly solitary animals, and males and females come together only to mate. Mating may take place at any time during the year. Males will often fight over the right to mate with a female, and males and females often fight during their courtship. After a gestation (pregnancy) period of 15 to 18 months, a female black rhinoceros gives birth to a single calf, which weighs about 90 pounds (41 kilograms). The calf nurses for up to two years and remains dependent on its mother for another year. Black rhinos have an average life span of 30 to 35 years.

Habitat and current distribution

The black rhinoceros prefers to inhabit open dry scrub-lands, savannas, dense thickets, and mountain forests. It is found only in small pockets in eastern and southern Africa. In 1995, the estimated population of the species was an all-time low of 2,410 animals. The number had risen to 2,700 by 1999.

History and conservation measures

Until it stabilized in 1995, the black rhinoceros was disappearing faster than any large animal on the planet. It once ranged widely throughout the savannas of Africa. In 1970, biologists (people who study living organisms) estimated that the black rhinoceros population numbered 65,000. By the late 1990s, that number had dropped by over 95 percent. At that rate black rhinos would be extinct by the early twenty-first century. It has been determined that the large populations of free-ranging rhinos have disappeared for the most part. Because they traveled over vast areas, they could not be adequately protected. The rhinos surviving in the early 2000s live within more concentrated areas in which they can be protected from hunters.

The direct cause for the decline of black rhinos has been the demand for their horns. For centuries, people in Asia have believed that the powder of ground rhino horns can cure fevers, nose bleeds, measles, food poisoning, and other illnesses. Many believe it increases sexual desire and stamina, as well. Rhino horns have also been used to make handles for the traditional "jambia" daggers worn by men in Yemen.

International treaties now outlaw the trade or sale of any rhino products. Nonetheless, poaching continues. A pound of rhino horn powder can sell for as much as $2,000. The animal's skin, blood, and urine are also sold. In the late 1980s, some wildlife agencies in Africa began tranquilizing black rhinos and removing their horns so the animals would not be as attractive to poachers. These attempts have proved fruitless, as over 100 dehorned black rhinos have since been slaughtered by poachers.

In 1994, the U.S. Congress passed the Rhino and Tiger Conservation Act. This measure provides financial assistance for the development of conservation measures for rhinos and tigers.