The donkey's wild ancestor is down to about 570 animals
Donkeys number in the millions, but their wild ancestor is one of the rarest large mammals in Africa. Only about 570 African wild asses remain, scattered across the deserts of Eritrea, Ethiopia and Somalia. The Somali subspecies even wears zebra-like black stripes on its legs, and can hit 70 kilometres an hour.
The African wild ass stands about 1.2 metres tall and weighs around 250 kilograms, with a pale grey to fawn coat, a white belly, a dark stripe down the back and an upright black-tipped mane. It once ranged north and west into Sudan, Egypt and Libya, and wild asses of unknown type lived in the Sahara and Arabia earlier in the Holocene. Whether the domestic donkey counts as the same species is a matter of taste; zoologists have deliberately kept the wild ass's own name, Equus africanus, so the ancestor is not filed under its descendant.
It is built for scarcity. A tough gut wrings moisture from sparse grasses, bark and leaves, though it still needs to drink roughly every three days and will accept salty water. Big ears sharpen hearing and shed heat. Because food is thin on the ground, animals spread out rather than bunching into tight herds, keeping in touch with brays that carry over 3 kilometres. Males patrol territories of about 23 square kilometres, marked with dung heaps, and tolerate subordinate rivals rather than chasing them off.
Unusually for a hoofed animal, a wild ass tends to investigate a threat before bolting, and it can kick with both front and hind legs. Foals are born after a pregnancy of 11 to 12 months, and animals can live up to 40 years in captivity. Capture for domestication, interbreeding with donkeys, hunting for food and traditional medicine, and competition with livestock for grazing and water have all driven the decline.
Zoos are an important backstop. Around 150 Somali wild asses live in collections worldwide, 36 of them born at Zoo Basel, which started breeding them in 1970. Every wild ass in Europe descends either from Basel's founders or from 12 animals sent from Israel's Yotvata Hai-Bar reserve in 1972.
Source: African wild ass
