The historical taxonomic treatment of the Plains Zebra is somewhat confusing. The Plains Zebra complex was long known as Equus burchelli, with the extinct form, the Quagga, recognized as a distinct species, E. quagga. Some evidence suggests that the ranges of the Quagga and the Plains Zebra form known as "Burchell's Zebra" (now E. quagga burchelli) overlapped in southern Africa without interbreeding. However, recent genetic analyses of both mitochondrial and nuclear DNA indicates that the genetic variation among extinct and extant Plains Zebras is no greater than that seen among modern breeds of the Domestic Horse (E. caballus). Thus, the Plains Zebra and the extinct Quagga are now treated as belonging to a single species, E. quagga.
Plains Zebras range from northern Kenya to southern Africa, with those in more southern poulations being larger and with less stripe coverage. These zebras are found in tropical, subtropical, and temperate grasslands, steppes, savannas, and woodlands. Only deserts, dense woodlands, and permanent wetlands are avoided. They occur from sea level to 4300 m (on Mount Kenya). They need to drink daily so they are never more than around half a day's travel (5 to 10 km) from a reliable water source.
Plans Zebras are true grazers and are active both day and night. As hindgut fermenters, they require large quantities of food and may spend up to 20 hours per day foraging.
Females give birth to a single offspring after a 12 month gestation period. Foals begin feeding on grass at a month, but continue to nurse for another 5 months. Females become sexually mature at two to three years. Males begin maintaining harems at around five years.
In 2002, there were an estimated 660,000 Plains Zebras. More than 75% of these are Grant's Zebras (E. q. boehmi), including around 200,000 in the Serengeti-Mara ecosystem. Although Plains Zebras appear to be well protected in much of Kenya and Tanzania, over much of their range they are threatened by poaching and habitat loss.
(Rubenstein 2011 and references therein)