Zebras
Zebras are striped members of the horse family (Equidae) native to Africa. These grazing animals stand 4–5 ft (1.2–1.5 m) high at the shoulders and are distinctive because of their striking white and black or dark brown stripes running alternately throughout their bodies. These stripes actually have important survival value for zebras, for when they are in a herd, the stripes tend to blend together in the bright African sunlight, making it hard for a lion or other predator to concentrate on a single individual and bring it down.
The zebra's best defense is flight, and it can outrun most of its enemies. It is thus most comfortable grazing and browsing in groups on the flat open plains and grasslands. Zebras are often seen standing in circles, their tails swishing away flies, each one facing in a different direction, alert for lions or other predators hiding in the tall grass.
Most zebras live on the grassy plains of East Africa, but some are found in mountainous areas. They live in small groups led by a stallion, and mares normally give birth to a colt every spring. Zebras are fierce fighters, and a kick can kill or cripple predators (lions, leopards, cheetahs, jackals, hyenas, and wild dogs). These predators usually pursue newborn zebras, or those that are weak, sick, injured, crippled, or very old, as those are the easiest and safest to catch and kill. Such predation helps keep the gene pool strong and healthy by eliminating the weak and diseased and ensuring the "survival of the fittest."
Zebras are extremely difficult to domesticate, and most attempts to do so have failed. They are often found grazing with wildebeest, hartebeest, and gazelle, since they all have separate nutritional requirements and do not compete with each other. Zebras prefer the coarse, flowering top layer of grasses, which are high in cellulose. Their trampling and grazing are helpful to the smaller wildebeest, who eat the leafy middle layer of grass that is higher in protein. And the small gazelles feed on the protein-rich young grass, shoots, and herb blossoms found closest to the ground.
One of the most famous African wildlife events is the seasonal 800-mi (1,287-km) migration in May and November of over a million zebras, wildebeest, and gazelles, sweeping across the Serengeti plains, as they have done for centuries, "in tides that flow as far as the eye can see." But it is now questionable how much longer such scenes will continue to take place.
Zebras were once widespread throughout southern and east Africa, from southern Egypt to Capetown. But hunting for sport, meat, and hides has greatly reduced the zebra's range and numbers, though it is still relatively numerous in the parks of East Africa. One species, once found in South Africa, the quagga (Equus quagga quagga) is already extinct, wiped out by colonists in search of hides to make grain sacks.
Several other species of zebra are threatened or endangered, such as Grevy's zebra (Equus grevyi) in Kenya, Ethiopia, and Somalia; Hartmann's mountain zebra (Equus zebra hartmannae) in Angola and Namibia; and the mountain zebra (Equus zebra zebra) in South Africa. The Cape mountain zebra has adapted to life on sheer mountain slopes and ravines where usually only wild goats and sheep can survive. In 1964, only about 25 mountain zebra could be found in the area, but after two decades of protection, the population had increased to several hundred in Cradock National Park in the Cape Province's Great Karroo area.
Probably the biggest long-term threat to the survival of the zebra is the exploding human population of Africa, which is growing so rapidly that it is crowding out the wildlife and intruding on the continent's parks and refuges. Political instability and the proliferation of high powered rifles in many countries also represent a threat to the survival of Africa's wildlife.
Resources
Periodicals
D'Alessio, V. "Born-Again Quagga Defies Extinction." New Scientist 132 (November 30, 1991): 14.
Grubb, P. "Equus burchelli." Mammalian Species no. 157, 1981.
Miller, J. A. "Telling a Quagga By Its Stripes." Science News 128 (August 3, 1985): 70.
Penzhorn, B. L. "Equus zebra." Mammalian Species no. 314, 1988.
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