- 18.9–25.2 in
- 48.4 in
- 28.2–74.1 oz
- Males are slightly larger than a Peregrine Falcon; females are about the size of a Red-tailed Hawk.
- Faucon gerfaut (French)
- Halcón gerifalte (Spanish)
- The Gyrfalcon hunts mostly ptarmigan, and its breeding distribution is strikingly similar to that of the Rock Ptarmigan. But it preys on many other bird species, including sage-grouse, jaegers, gulls, terns, fulmars, auks, pheasants, hawks, owls, ravens, and songbirds. It can also hunt mammals as big as hares.
- When their chicks are too small to eat an entire prey item in one meal, female Gyrfalcons store leftovers behind vegetation within a few hundred feet of the nest, and retrieve the food later for themselves or their chicks. 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.
- During the breeding season, a family of Gyrfalcons needs an estimated 2–3 pounds of food per day. That’s about 2-3 ptarmigans per day, which adds up to about 150-200 ptarmigan consumed between courtship and fledging.
- 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.
- Male Gyrfalcons are commonly seen capturing fledgling songbirds in the area around the nest. They probably seek small prey only when it can be obtained quickly, since larger prey provides a bigger payoff for their efforts.
- Adult males are much smaller than females: males average less than 3 pounds while females average up to 4 pounds. Both males and females have highly variable plumage coloration, ranging from nearly pure white to dark gray-brown. In North America, most are an intermediate gray color.
- The oldest Gyrfalcon recorded was a male and at least 15 years, 9 months when he was identified by his band in 2016 in Wisconsin. He had been banded in the same state in 2003.
The Gyrfalcon breeds in arctic and alpine tundra in northern Canada and Alaska, in areas with abundant ptarmigan or near colonies of nesting seabirds or waterfowl. Habitats include rocky seacoasts, offshore islands, barren lands with rocky outcrops, river bluffs, lake bluffs, and mountainous terrain up to more than 5,000 feet in elevation. The low vegetation in their habitat includes species of sedge, cottongrass, lichen, moss, willow, and birch. They sometimes venture into margins of boreal forest or small stands of spruce along beaches or dunes. In winter they probably vacate the highest latitudes and elevations, and may range as far south as the northern United States. There they are usually found in open areas below 3,000 feet in elevation with abundant birds for prey, including coasts, reservoirs, farmland, grasslands, shrublands, and river valleys.
Gyrfalcons rely heavily on Willow Ptarmigan and Rock Ptarmigan but also hunt other birds, including seabirds, waterfowl, shorebirds and songbirds. They have been known to capture sage-grouse, jaegers, gulls, terns, fulmars, alcids, pheasants, hawks, owls, falcons, ravens, crows, magpies, redpolls, Savannah Sparrows, Lapland Longspurs, and Snow Buntings. They may also hunt mammals such as hares, ground squirrels, lemmings, and young arctic fox. The Gyrfalcon spots prey from a high perch or on the wing. It makes most of its captures by striking prey and driving it to the ground rather than grasping it in the air; the prey usually ends up with a broken breastbone. The Gyrfalcon may fly low and sneak up on its victims, chase prey over a long distance to tire it out, or hover and dive. Females often cache food temporarily during the breeding season, storing it behind vegetation within several hundred feet of the nest site.
- Clutch Size
- 1–5 eggs
- Number of Broods
- 1 broods
- Egg Length
- 2.2–2.4 in
- Egg Width
- 1.7–1.9 in
- Incubation Period
- 34–36 days
- Nestling Period
- 45–50 days
- Egg Description
- Ranging from white to reddish brown, with variable cinnamon spots.
- Condition at Hatching
- Covered with thick down, with eyes open; capable of sitting up and begging shortly after hatching.
The nest ranges from bare or debris-covered soil to a structure of dead sticks, usually with little or no lining. Although Gyrfalcons do not build nests themselves, both the male and the female contribute to scraping a hollow depression in the center.
Gyrfalcons nest on cliffs or in conifer tree nests of other species, such as Common Ravens and Golden Eagles. They may nest directly on cliff ledges, often protected by overhangs oriented away from the wind. Both males and females visit nesting cliffs before beginning to breed; the males outnumber the females and advertise for mates.
Gyrfalcons usually spend the whole year alone or in pairs, and they appear to mate for life. The male performs spectacular aerial displays with dives and rolls. Around the pair’s cliffside nest they defend a territory nearly a mile wide, usually spaced between 3 and 60 miles from the nearest pair. They call aggressively to maintain the territory, and both the male and female may chase and strike at intruders—including Common Ravens, Rough-legged Hawks, and Peregrine Falcons—during breeding or nonbreeding season. They may also lock talons with intruders; sometimes two combatants strike the ground still locked together. Gyrfalcons may be mobbed by small songbirds. They are capable of very fast flight, and may reach speeds of 130 miles per hour when stooping for prey. They sometimes run or hop onto rocks to chase prey.
Gyrfalcons show no evidence of long-term population changes in North America. Partners in Flight estimates the global breeding population at 70,000 individuals, with 43% spending part of the year in Canada, and 11% ranging into the U.S. during the winter. This is a U.S.-Canada Stewardship species and rates a 9 out of 20 on the Continental Concern Score. The species is not on the 2016 State of North America's Birds' Watch List, and are not being actively managed. However, there has been controversy about the effect of their use in falconry in other parts of the world. Declines in Scandinavia and the vicinity have been attributed to falconry, habitat modification, and egg collection. Other threats include shooting in Iceland and accidental capture by ptarmigan traps or fox traps in Russia. The remote breeding range of North American Gyrfalcons has kept them safe from such threats, though human disturbance does sometimes deter them from returning to nest sites in later years. The most significant current threat is climate change, which has begun to transform the landscape within their range.
- Booms, T.L., T.J. Cade, and N.J. Clum. 2008. Gyrfalcon (Falco rusticolus). In The Birds of North America Online, No. 114 (A. Poole, Ed.). Cornell Lab of Ornithology, Ithaca, New York.
- Crossley, R., J. Ligouri, and B. Sullivan. 2013. The Crossley ID Guide: Raptors. Princeton University Press, Princeton, NJ.
- North American Bird Conservation Initiative. 2016. The State of North
America’s Birds 2016. Environment and Climate Change Canada: Ottawa, Ontario.
- Partners in Flight. 2012. Species assessment database.
- Sibley, D.A. 2014. The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York.
- USGS Patuxent Wildlife Research Center. 2016. Longevity records of North American Birds.
Resident to medium-distance migrant. Most Gyrfalcons that breed below 70 degrees latitude are probably year-round residents. Those that breed farther north migrate south for the winter.
Find This Bird
Because Gyrfalcons breed so far north, most people encounter them as rarities spotted during winter in the northernmost U.S. and southern Canada. In these areas the birds look for tundra-like habitat including plains, open agricultural land, and coastlines. Peregrine Falcons can look very similar, so be sure to look for the Gyrfalcons bulky body and relatively thick, blunt-tipped wings. Gyrfalcons are used to perching on the ground, so don’t just search the skies—be sure to scan open stretches of ground, where they may be standing at rest or sheltering next to a rock or shrub.