and burros are generally considered an introduced species because they are descendants from domestic horses brought to the Americas from Europe. While they are viewed as pests by many livestock producers, conversely, a view also exists that E. f. caballus is a reintroduced once-native species returned to the Americas that should be granted endangered species protection. At present, certain free-roaming horses and burros have federal protection as "living symbols of the historic and pioneer spirit of the West" under the Wild and Free-Roaming Horses and Burros Act of 1971, and in Kleppe v. New Mexico, the United States Supreme Court ruled that the animals so designated were, as a matter of law, wildlife. References External links Mammal genera Extant Calabrian first appearances Taxa named by Carl Linnaeus