(Falco rusticolus), the largest of the falcon species, is a bird of prey. It breeds on coasts and tundra, and the islands of northern North America and the Eurosiberian region. It is mainly a resident there also, but some gyrfalcons disperse more widely after the breeding season, or in winter. Individual vagrancy can take birds for long distances. Its plumage varies with location, with birds being color from all-white to dark brown. These color variations are call morphs. For centuries, the gyrfalcon has been value as a hunting bird.
The Gyrfalcon breeds in arctic and alpine tundra in northern Canada and Alaska, in areas with abundant ptarmigan or near colonies of nesting seabirds or waterfowl. The low vegetation in their habitat includes species of sedge, cottongrass, lichen, moss, willow, and birch. They sometimes venture into margins of boreal forest or small stands of spruce along beaches or dunes. In winter they probably vacate the highest latitudes and elevations, and may range as far south as the northern United States. There they are usually found in open areas below 3,000 feet in elevation with abundant birds for prey, including coasts, reservoirs, farmland, grasslands, shrublands, and river valleys.