Description

Antelopes of both families are noted for their beauty, grace, and speed in running. Most are distinguished by upswept, back-curving horns. Their coats of hair are usually golden, reddish tan, or grey, often with white beneath and on the face and rump. Some are strikingly marked. The bongo is red-orange with 12 thin white stripes down its side. The sable antelope is, as its name suggests, a rich, deep brown and black. The pronghorn is reddish brown with white underneath, two white bands on the throat, and a short, dark-brown mane. It can raise the hair on a round white patch on its rump to produce a vivid flash of white. It apparently does this as a signal to warn other animals of danger.

Antelopes have moderately developed brains and acute senses of smell and hearing. These, along with their unusual agility and speed, allow them to detect any lurking danger quickly and leap to safety.

Most antelopes are the size of goats and deer. The largest and tallest is the stately giant eland of Africa, a sturdily built animal standing about 69 inches (175 centimeters) tall at the shoulders and weighing about 1,764 pounds (800 kilograms). The smallest is the dainty royal, also of Africa, standing about 10 inches (25 centimeters) tall at the shoulders and weighing only about 6 pounds (2.7 kilograms). The pronghorn is medium-sized, with a shoulder height of about 35 inches (90 centimeters).

Horns take many shapes and sizes among antelopes of the Bovidae family. The royal has spikes only one inch (2.5 centimeters) long; the giant sable antelope has imposing arcs, 63 inches (160 centimeters) long; the kudu has gracefully twisting spirals; the impala has long, elegant, lyre-shaped horns. None of the antelopes of the Bovidae family has branched horns, but the pronghorn has horns that branch from an erect stem into two prongs, the longer prong curving backwards and the shorter jutting forward. In some species, including the pronghorn, both the buck (male) and the doe (female) have horns. The four-horned antelope of India has two pairs of horns, one on its forehead and a larger pair on top of its head.

Antelope horns consist of a core of bone, an extension of the bone of the forehead, covered by a horny sheath. Antelopes of the Bovidae family never shed their horns, but the pronghorn sheds the horny sheath each year after the breeding season when a new sheath develops under the old one.

Living Habits

Antelopes are herbivores—that is, they feed on grass and other plants. Since plants vary with the seasons, antelopes depend upon a succession of grasses, foliage, and other vegetation, and may eat a great variety. They have large, mobile tongues that they thrust forward to graze or browse. They are selective and often prefer similar parts of different plants rather than all of the same plant. Antelopes are ruminants (animals that chew the cud). They swallow their food and store it in the rumen, the first chamber of their stomachs; they later regurgitate it for chewing at leisure. Compared to carnivores (meat-eating animals), antelopes have larger stomachs and longer intestines because plants are somewhat more difficult to digest than meat.

The pronghorn can run 43 miles (70 kilometers) per hour and leap 20 feet (6 meters). Thomson's gazelle can run 50 miles (80 kilometers) per hour. The impala, noted for its great springing leaps, can jump to a height of 7⁹/₁₀ feet (2.4 meters) and cover 33 feet (10 meters) in a bound. The duiker is noted for quick, zigzag leaps and frenetic plunges into dense underbrush. In fast running, galloping, and bounding, antelopes raise their two front legs, one immediately after the other, then their two back legs, which give the animals their main propulsive thrust. In walking, they take a more stable position on diagonally opposite legs and move them in the order: left front, right rear; right front, left rear.

Antelopes are related to deer, camels, giraffes, and pigs, all of which belong to the order Artiodactyla, the even-toed ungulates (mammals that walk and run on their hoofs). Antelopes lost their “thumbs” and “big toes” at an early stage of evolution. They stand on the tips of their two center toes, which developed the large toenails that thickened and became hoofs (the so-called cloven, or split hoof, which is two toenails close together). The antelope's two outer toes became nonfunctional.

The antelope's great freedom of motion in running and leaping is partly due to an unusual anklebone. One of the bones between the leg and the foot, the astragalus, is pulley-shaped at both the upper and lower ends in Artiodactyls, in contrast to other mammals in which the bone is flat at the lower end and pulley-shaped only at the top.

Native Habitats

Fossil records indicate that antelopes of the family Bovidae lived on the Eurasian continent and in Africa as long as 65 million years ago. Some still roam the central and southwest regions of Eurasia, but in the north temperate zones the winters are too severe to permit continued feeding on grasslands. The greatest number and variety of antelopes are now found in the grassy savannas, or plains, of Africa.

The American pronghorn once roamed the open plains and semi-deserts from Alberta, Canada, to northern Mexico. It lived alone or in small bands in summer and in large herds during the winter. Since the settlement of the Western United States, the number of pronghorns has been considerably reduced by hunting, while many of their grazing areas have been pushed back by civilization.

Antelopes make no permanent shelter, but roam about on a particular range where they make their home. In their grazing habits they follow a cyclic route that may cover more than 200 square miles (500 square kilometers) in a year. They generally travel in herds numbering several hundred antelopes. Some of them will travel with one herd in the summer and another during the winter. A few may seek solitude in marshes, along riverbanks, in dense tropical forests, on cliffs, and even in desert regions. These are usually old, infirm animals, bucks with no mates, or does about to give birth. A doe will eventually return to the herd once her young can follow her.

Life Cycle

In the mating season male antelopes hold territories on which they attempt to detain a passing doe. They mark these territories as their own by rubbing their scent glands against plants and trees. Many species have scent glands in front of the eye, while others have them behind the horns, on the jaws, or on the tail, back, or feet. The American pronghorn and the African blackbuck, gazelle, and oribi are especially well endowed with such glands.

To defend his territory a buck will signal his intention to fight. Two males will lock horns and wrestle in a seemingly ritualized style that will not do either animal great harm. The African eland, however, has been known to fight to the death. Some antelopes gather harems of mates in the summer. Others have only one mate.

The gestation period, the time the doe carries her young before it is born, varies from four to eight months with the size of the species. In temperate climates birth takes place in spring or early summer. In tropical areas most births take place late in the rainy season or shortly afterward. Does normally have one young at each birth, but the pronghorn and the four-horned antelope frequently have twins. Newborn animals are well-developed and may weigh one tenth as much as the mother.

Enemies

Tigers, lions, leopards, and other predators have a limited effect on a population of healthy and alert adult antelopes. It is the youngest and oldest that normally fall prey. While one animal in a herd may be killed, the others will escape.

Disease is also a marginal danger, although undernourished antelopes are susceptible to parasites. The African tse-tse fly carries disease-causing parasites, but the animals normally rid themselves of these pests by stamping their feet, twitching their skin, or shaking their heads and bodies.

The most dangerous threat to the existence of the antelope is the big-game hunter. Prime targets are the larger animals: eland, roan, greater kudu, waterbuck, nilgai (blue bull of India), mountain nyala, and bongo. Some species are almost extinct: the Arabian oryx, giant sable, blesbok, and bontebok. Others, formerly in danger of extinction, have been able to increase their numbers in preserves.