This formidable predator, the largest falcon in the world, reigns over barren tundra and desolate coasts in the high Arctic. There it preys mostly on large birds such as ptarmigan and waterfowl, overtaking them in powerful flight. Most Gyrfalcons remain in the far North all year; only a few come as far South as the Canadian border in winter, providing thrills for birders. Variable in color, Gyrs may be blackish, gray, or stunningly white.