The donkey or ass is a domesticated equine. It derives from the African wild ass , Equus africanus , and may be classified either as a subspecies thereof, Equus africanus asinus , or as a separate species , Equus asinus. There are more than 40 million donkeys in the world, mostly in underdeveloped countries, where they are used principally as draught or pack animals.
While working donkeys are often associated with those living at or below subsistence, small numbers of donkeys or asses are kept for breeding, as pets, and for livestock protection in developed countries. An adult male donkey is a jack or jackass , an adult female is a jenny or jennet , [ 4 ] [ 5 ] [ 6 ] and an immature donkey of either sex is a foal. Traditionally, the scientific name for the donkey is Equus asinus asinus , on the basis of the principle of priority used for scientific names of animals.
However, the International Commission on Zoological Nomenclature ruled in that if the domestic and the wild species are considered subspecies of a common species, the scientific name of the wild species has priority, even when that subspecies was described after the domestic subspecies. At one time, the synonym ass was the more common term for the donkey. The first recorded use of donkey was in either [ 9 ] or Hypotheses on its derivation include the following:.
From the 18th century, donkey gradually replaced ass and jenny replaced she-ass , which is now considered archaic. By the end of the 17th century, changes in pronunciation of both ass and arse had caused them to become homophones in some varieties of English.
Burro is a word for donkey in both Spanish and Portuguese. In the United States, it is commonly applied to the feral donkeys that live west of the Rocky Mountains ; [ 16 ] it may also refer to any small donkey. The genus Equus , which includes all extant equines, is believed to have evolved from Dinohippus , via the intermediate form Plesippus.
