The Gyrfalcon is the largest of all falcons, with females substantially larger than males. They are the most northern of the diurnal raptors. Like other falcons, they have dark eyes, and a short, strong beak with a tomial tooth used for killing prey. Their bodies are streamlined, hard and compact with smallish heads and long pointed wings. As with other bird-catching raptors, their toes are long and thin. There is no sexual color dimorphism in this species but individuals do vary greatly in color, from pure white to uniform dark gray-brown. Tail may be barred or unbarred. The Gyrfalcon is distinguished from the Peregrine Falcon (Falco peregrinus) by the lack of a dark cap and a crown and/or nape that is heavily streaked. The Gyrfalcon also has a shorter, broader wing base with a rounder wing tip than does the Peregrine. The flight of the Gyrfalcon is more buoyant, and they are capable of more sustained flight, but are less maneuverable than the Peregrine.