A large eagle (Aquila chrysaetos) of mountainous areas of the Northern Hemisphere, having dark plumage with brownish-yellow feathers on the back of the head and neck. a large light brown bird that lives in northern parts of the world. Dark-brown eagle (Aquila chrysaetos) with golden, leaf-shaped nape feathers, dark eyes, gray beak, fully feathered legs, large yellow feet, and large talons. Its wingspread reaches almost 8 ft (2.3 m). It ranges from central Mexico (where it is the national bird) along the Pacific coast and through the Rocky Mountains to Alaska, and small numbers are found from Newfoundland to North Carolina. Also found in North Africa, it is more common across Russia, to southern China and Japan. It nests in cliff caves or in lone trees. The species is protected in the U.S