Zebras are wild African equids that include plains zebras, mountain zebras, and Grevy’s zebras. Depending on species, mature males may weigh about 600–1,000 pounds, while females usually weigh about 500–800 pounds. Zebras are best known for their black-and-white striping, upright manes, strong herd instincts, and alert behavior. Plains zebras live in savannas and grasslands, mountain zebras in rugged dry terrain, and Grevy’s zebras in arid East African landscapes. Zebras were introduced into U.S. zoos in the late 1800s and early 1900s, with private exotic ranch, safari park, and educational ownership expanding during the 20th century.