North American donkeys constitute approximately 0.1% of the worldwide donkey population. Donkeys were brought from Europe to the New World in the fifteenth century with the Second Voyage of Christopher Columbus, and subsequently spread into Mexico. They first reached what is now the United States in the late seventeenth century. Donkeys arrived in large numbers in the western United States during the gold rushes of the nineteenth century, as pack animals and for use in mines and ore-grinding mills. From about 1785, some large donkeys were imported from Europe to the eastern part of the continent. There are no true-breeding North American donkey breeds. Breed societies in Canada and the United States register donkeys according to their size, as miniature, standard or mammoth donkeys. These are reported as breeds to the Domestic Animal Diversity database of the Food and Agriculture Organization of the United Nations by the National Animal Germplasm Program of the Agricultural Research Service of the US Department of Agriculture, as are the Burro – a feral population of the western United States – and the Spotted, a color breed. History The first asses came to the Americas on ships of the second voyage of Christopher Columbus, and were landed at Hispaniola in 1495. In the early days of the Conquest, jackasses were highly valued as sires for mules, which were esteemed as riding animals by the Spanish, and reserved for the nobility. Mules were bred for expeditions to mainland America, with males preferred for pack animals and the females for riding. The first shipment of mules, along with three jacks and twelve jennies, arrived in Mexico from Cuba ten years after the conquest of the Aztecs in 1521. Mules were used in silver mines, and each Spanish outpost in the empire bred its own mules from its own jack. The first presence of donkeys in what is now the United States is sometimes reported to date from 1679, when a Jesuit priest named Eusebio Kino took some from Sonora in Spanish Mexico to a new mission at San Xavier del Bac in what is now Arizona; however, Kino did not reach the Americas before about 1681, and was not in Sonora until 1687. Donkeys arrived in large numbers in the western United States during the gold rushes of the nineteenth century, as pack animals and for use in mines and ore-grinding mills. The major use of donkeys