[5] The short, smooth coat is a light grey to fawn colour, fading quickly to white on the undersides and legs.

The genus appears to have spread quickly into the Old World, with the similarly aged Equus livenzovensis documented from western Europe and Russia.

[7] Molecular phylogenies indicate the most recent common ancestor of all modern equids (members of the genus Equus) lived ~5.6 (3.9–7.8) mya.

[8] The oldest divergencies are the Asian hemiones (subgenus E. (Asinus), including the kulan, onager, and kiang), followed by the African zebras (subgenera E. (Dolichohippus), and E. (Hippotigris)).

[11] The name Equus taeniopus von Heuglin, 1861[12] is rejected as indeterminable, as it is based on an animal that cannot be identified and may have been a hybrid between a domestic donkey and a Somali wild ass; the type has not been preserved.

[2][11] A lectotype is designated: a skull of an adult female collected by von Heuglin near Atbarah River, Sudan, and present in the State Museum of Natural History Stuttgart, MNS 32026.

[1] They have very loud voices, which can be heard for over 3 km (1.9 mi), which helps them to keep in contact with other asses over the wide spaces of the desert.

The African wild ass is primarily active in the cooler hours between late afternoon and early morning, seeking shade and shelter amongst the rocky hills during the day.

[21] Mature males defend large territories around 23 square kilometres in size, marking them with dung heaps – an essential marker in the flat, monotonous terrain.

Despite being primarily adapted for living in an arid climate, they are dependent on water, and when not receiving the needed moisture from vegetation, they must drink at least once every three days.

Though the species itself is under no threat of extinction, due to abundant domestic stock (donkeys and burros), the two extant wild subspecies are both listed as critically endangered.

[1] Competition with domestic livestock for grazing, and restricted access to water supplies caused by agricultural developments, pose further threats to the survival of this species.

[1] The African wild ass is legally protected in the countries where it is currently found, although these measures often prove difficult to enforce.

A protected population of the Somali wild ass exists in the Yotvata Hai-Bar Nature Reserve in Israel, to the north of Eilat.

[27] All European wild donkeys are either descendants of the original group at Zoo Basel or of 12 others that came from the Yotvata Hai-Bar Nature Reserve in Israel in 1972.