Donkey the environment. They may compete with livestock and native animals for resources, spread weeds and diseases, foul or damage watering holes and cause erosion. Few species of ass exist in the wild. The African wild ass, "Equus africanus", has two subspecies, the Somali wild ass, "Equus africanus somaliensis", and the Nubian wild ass, "Equus africanus africanus", the principal ancestor of the domestic donkey. Both are critically endangered. Extinct species include the European ass, "Equus hydruntinus", which became extinct during the Neolithic, and the North African wild ass, "Equus africanus atlanticus", which became extinct in Roman times. There are five subspecies
African wild ass female collected by von Heuglin near Atbarah River, Sudan, and present in the State Museum of Natural History Stuttgart, MNS 32026. The two subspecies recognized are the Nubian wild ass "Equus africanus africanus" (von Heuglin & Fitzinger, 1866), and the Somali wild ass "Equus africanus somaliensis" (Noack, 1884). African wild asses are well suited to life in a desert or semidesert environment. They have tough digestive systems, which can break down desert vegetation and extract moisture from food efficiently. They can also go without water for a fairly long time. Their large ears give them an excellent sense of hearing