Brian E. Small
Gyrfalcon — even the name has kind of a magical ring to it. This king of the high Arctic is the largest falcon in the world — measuring 20 to 25 inches long — and perhaps the most awesome winged predator. The Gyrfalcon (Falco rusticolus) is also the rarest and most difficult of all North American raptors to find. Because it is such a rare raptor to find south of the Canadian border, the online birding forums generate a lot of excitement when one is reported.
The Gyrfalcon's worldwide range is circumpolar, and it is found in some of the most remote and desolate regions on Earth. The bird appears in various color morphs ranging from almost black to gray and even white.
In North America, the Gyrfalcon's breeding range extends from western Alaska across the high Arctic to northeastern Canada. The great majority of Gyrs spend the entire year in the far north; however, birders have a reasonable chance to find one during winter in a number of semireliable locations without making the trip to the Arctic. The Skagit Flats in Washington state; the Canadian plains near Calgary, Alberta; Sault Ste. Marie, Ontario; Michigan and parts of Newfoundland are the best places to look for Gyrfalcons in winter.
Along the deserted coasts, lonely rivers and barren tundra of Alaska and northern Canada, the Gyrfalcon stands at the top of the avian food chain. During summer, it may hunt for various Arctic-nesting birds, but during winter, its primary food source is ptarmigan. In years that ptarmigan populations are high, Gyrfalcons usually don't leave the Arctic even in winter. When ptarmigan populations are low, Gyrfalcons wander farther south in search of food.
Gyrfalcons hunt for their prey by scanning their surroundings from a perch on a high rock outcrop or while flying. When a target is sighted, the Gyrfalcon flies very low to the ground using rapid, shallow wing beats and then uses the element of surprise to capture its prey. The speed and power of a Gyrfalcon are usually no match for a slow-moving ptarmigan, duck or goose.
Gyrfalcon numbers (4,000 to 5,000) are fairly stable in North America, but the species has declined in parts of arctic Europe. It appears the biggest threat to the Gyrfalcon is the illegal falconry industry. Falconry is still a high-prestige activity for the elite in parts of the Middle East, and a great demand for the world's largest falcon continues. There are reports of birds being sold for as much as $100,000.
Mating: Adults engage in an aerial courtship display that includes steep diving. Also, both adults display at the nest site by bowing and scraping, and the male brings food to the female.
Nest Sites: The majority of nests are on cliffs, and occasionally nesting occurs on a bare open ledge or in an old nest in a tree.
Nest: Gyrfalcons often use old nests of other birds, such as Golden Eagles or ravens. It usually consists of a bulky platform of sticks and twigs lined with leaves, moss, weeds and grass. Gyrfalcons do not add material to existing nests. Clutch: Usually three to five whitish eggs spotted with cinnamon-brown. Can be as few as two eggs and as many as eight.
Incubation Period: About 35 days, with most of the incubation is done by the female.
Nestling Period: The female stays mostly with the semialtricial young for the first three weeks. During this time, the male brings food and the female feeds it to the young. After three weeks, the female begins to hunt on her own.
Fledging Period: The young Gyrfalcons usually fly for the first time about seven weeks after hatching.
Food: Mostly medium to large birds like ptarmigan, gulls, ducks and geese. They also eat some mammals such as lemmings, ground squirrels and hares.