General
Gyrfalcon: Large northern falcon that has three color morphs: dark, white, and gray. Dark morph is dark gray with pale streaks on throat and upper breast. White morph is mostly white with dark spots and markings on wings, nape, and sides. Gray morph is intermediate. Eyes, bill, and legs of all three morphs are yellow. Sexes are similar. Juvenile has gray eyes, bill, and legs.
Range and Habitat
Gyrfalcon: Breeds on tundra in northern Alaska and Canada. Spends winters in breeding range and regularly (but rarely) south to the northern tier of states, especially along coasts. Found in boreal forests, cliffs, and coastal areas.
Breeding and Nesting
Gyrfalcon: Three to eight white, buff, or pale yellow eggs with small red spots are laid in an abandoned stick nest, usually built by ravens. Incubation ranges from 28 to 36 days and is carried out by the female.
Foraging and Feeding
Gyrfalcon: Prey consists of ptarmigans, ground squirrels, hares, mice, voles, ducks, and other birds; hunts while soaring.
Vocalization
Gyrfalcon: Alarm call is a deep, harsh "hyaik-hyaik-hyaik" or "kack-kack-kack."
Similar Species
Gyrfalcon: Prairie and Peregrine falcons resemble darker morphs, but are smaller with thinner wings and tails, and lack pale flight feathers contrasting with darker wing linings; Prairie Falcon has a black underwing patch while the Peregrine has evenly dark underwings.