boulder fields and in the mountains. On the flat, it has been recorded reaching speeds of . In keeping with these feats, its soles are particularly hard and its hooves grow very quickly. Mature males defend large territories around 23 square kilometres in size, marking them with dung heaps – an essential marker in the flat, monotonous terrain. Due to the size of these ranges, the dominant male cannot exclude other males. Rather, intruders are tolerated – recognized and treated as subordinates, and kept as far away as possible from any of the resident females. In the presence of estrous females, the males bray loudly. These animals live in loose herds of up to fifty individuals. In the wild, African wild ass breeding occurs during the wet season. The gestation period lasts for 11 to 12 months, and one foal is born during the period from October to February. The foal weans for 6 to 8 months after birth, reaching sexual maturity at the age of 2 years. Lifespan is up to 40 years in captivity. Wild asses can run swiftly, almost as fast as a horse. However, unlike most hoofed mammals, their tendency is to not flee right away from a potentially dangerous situation, but to investigate first before deciding what to do. When they need to, they can defend themselves with kicks from both their front and hind legs. Equids were used in ancient Sumer to pull wagons circa 2600 BC, and then chariots on the Standard of Ur, circa 2000 BC. These have been suggested to represent onagers, but are now thought to have been domesticated asses. Diet The African wild asses' diet consists of grasses, bark, and leaves. 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. However, they can survive on a surprisingly small amount of liquid, and have been reported to drink salty or brackish water. Conservation status 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. African wild asses have been captured for domestication for centuries and this, along with interbreeding between wild and domestic animals, has caused a distinct decline in population numbers. There are now only a