Bald eagle, large bird of prey that lives in North America, where it feeds on fish and small mammals. It is brown with a white head and tail and a yellow bill. Its tail feathers were used in the headdresses of some American Indians, and it is the national emblem of the U.S.A. Although now protected by law, it is an endangered species. Length: 71-96cm. Family Accipitridae; species Haliaeetus leucocephalus.