Measurements
Both Sexes
- Length
- 18.9–25.2 in
48–64 cm - Wingspan
- 48.4 in
123 cm - Weight
- 28.2–74.1 oz
800–2100 g
Other Names
- Faucon gerfaut (French)
- Halcón gerifalte (Spanish)
Cool Facts
- The Gyrfalcon eats mostly ptarmigan, but many other prey species have been recorded, including fulmars, gulls, jaegers, ducks, geese, Rough-legged Hawk, Short-eared Owl, sparrows, buntings, and redpolls.
- The female Gyrfalcon regularly stores prey during the breeding season, generally within 100 meters (328 feet) of the nest. Little is known of food-caching outside the breeding season; in one case, a Gyrfalcon was seen retrieving a frozen ptarmigan and chipping off pieces of meat to eat, in mid-winter in the Aleutian Islands.
- Gyrfalcon is pronounced as "JER-falcon." The name probably evolved from Old Norse, but linguists do not completely agree on the specific origin of the word.
- The Gyrfalcon sometimes bathes in runoff water of still-frozen rivers.
Habitat
Mountains
Breeds in tundra, often near rivers or coasts. Winter habitat similar; at lower latitudes, open country, especially near water.
Food
Birds
Mostly birds, especially ptarmigan. Also consumes mammals, ranging in size from voles to hares.
Nesting
Nesting Facts
- Clutch Size
- 1–5 eggs
- Egg Description
- White with variable cinnamon spots; may be mostly brown.
- Condition at Hatching
- Covered with thick down; capable of sitting up and begging shortly after hatching.
Nest Description
Does not build nest; usually uses nests built by other species, including Common Raven and Golden Eagle, usually on cliff ledge.
Nest Placement
Cliff
Behavior
Aerial Dive
Male performs spectacular aerial displays with dives and 180° rolls. Uses four methods to pursue prey: 1) flying low and surprising prey on ground; 2) pursuing prey over long distances, forcing it low or high and exhausting it; 3) hovering and making short stoops to force prey out of cover; 4) flying straight up to strike at birds overhead. Strikes prey or drives it to the ground, rather than grasping it in the air; dead prey typically have broken breast bone.
Conservation
Least Concern
No evidence of long-term population changes in North America. Commercial markets in falconry may pose a threat in Scandinavia and Russia.
Credits
- Clum, N. J., and T. J. Cade. 1994. Gyrfalcon (Falco rusticolus). In The Birds of North America, No. 114 (A. Poole and F. Gill, Eds.). Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists' Union.