Of all the falcons, gyrfalcons are the largest, with a wingspan of four feet.  Gyrfalcons live in the high latitudes near the North Pole, where they can have     grey phases and white phases with black spots. But in western North America, high in the Arctic, the plumage of the gyrfalcon is almost pure white. All raptors are fascinating hunters. But unlike the peregrine falcon, which soars above its  prey and then dives to knock it to the ground with its hind claw, the gyrfalcon overtakes its prey in level flight. Taking prey in this manner requires  exceptional speed for so large a creature.