The Asiatic wild ass is larger than the African wild ass at about and (head-body length). They are reddish-brown or yellowish-brown in color and have broad dorsal stripe on the middle of the back. Unlike most horses and donkeys, onagers have never been domesticated. They are among the fastest mammals, as they can run as fast as 64 km/h (40 mph) to 70 km/h (43 mph). The onager is closely related to the African wild ass, as they both shared the same ancestor. The kiang, formerly considered a subspecies of "Equus hemionus", diverged from the Asiatic wild ass and has been acknowledged as a distinct species.