Description and biology
A member of the horse family, the Grevy’s zebra is similar in appearance to a mule. It has an average head and body length of 8 to 10 feet (2.4 to 3 meters) and a shoulder height of 4.5 to 5 feet (1.4 to 1.5 meters). It weighs between 800 and 950 pounds (360 and 430 kilograms). The animal has a large head, rounded ears, a tufted tail, and a short, stiff mane. It feeds primarily on grass. Lions, hyenas, and crocodiles are the Grevy’s zebra’s main predators.
A beautiful pattern of narrow black and white vertical stripes covers most of the Grevy’s zebra’s head and body. A dark stripe runs down the top of its back. Its belly is white. Scientists once thought that the stripes on zebras served to camouflage or protect the animals from predators. Some researchers now believe the stripes help the animals recognize other members of their group and, thus, form social bonds.
Some scientists now believe that Grevy’s zebra’s black-and-white stripes help it to distinguish other members of its group.
Grevy’s zebras are unique among zebras in that they do not form permanent groups. Nursing females and their foals (young), other females, and solitary males sometimes gather in temporary herds. Some males establish territories ranging between 1 and 4 square miles (2.6 and 10.4 square kilometers) and will compete with other males over the right to mate with females in their territory. Mating takes place any time of the year, but peaks in mid-summer and mid-fall. After a gestation (pregnancy) period of 390 days, a female Grevy’s zebra gives birth to a single foal. The newborn foal is brown and black in color, and its mane extends down its back to its tail. After four months, it develops adult coloring. The foal may remain with its mother for up to three years.
Habitat and current distribution
Grevy’s zebras inhabit the semiarid (semidry) scrublands and grasslands in southern Ethiopia and Kenya. Although unsure of the total number of Grevy’s zebras currently in existence, scientists believe that number is declining.
History and conservation measures
Between the late 1970s and late 1980s, the Grevy’s zebra population decreased by 70 percent. Once populous in Somalia, the animal is now extinct there. Hunting for its beautiful skin was the main reason for its decline in early years. The animal is now legally protected, and poaching (illegal hunting) is not considered a major problem.
The principal current threat to the Grevy’s zebra is the loss of its habitat. Increasing numbers of domestic livestock now graze on the animal’s food source. Much of the water that flowed through its semiarid habitat in Kenya has been diverted to irrigate nearby developing farmland.