The gyrfalcon’s name is thought to be derived from the Latin hierofalco, meaning "sacred falcon" in reference to the bird’s exalted position in falconry, where it was traditionally reserved for use by only kings and princes. Alternatively, it may come from the old German gir, meaning "greedy", recognizing the bird’s voracious appetite. The scientific name is Falco rusticolus, which is Latin for "falcon living in the country", acknowledging its tundra habitat. The species has also been known as jer-falcon, gerfalcon, Greenland falcon, and Iceland falcon.

Description and identification tips:
The largest of the world’s falcons, the gyrfalcon has a heavier body, broader wings, and longer tail than the peregrine. Males range in size from 50-54 cm, with a wingspan of 110-120 cm, and a weight of 1.0-1.3 kg. Females are much heavier, ranging from 1.4-2.1 kg, and are visibly larger with a length of 57-61 cm and a wingspan of 124-130 cm.

The Gyrfalcon is unusual among birds in having three distinct colour morphs, generally referred to as white, gray, and dark (or black). White morph birds often lack a malar stripe on the face, are only faintly marked with black flecks below, and moderately barred with black above. The gray form is a fairly uniform slate-gray above, and whitish below with dark barring, and usually has a distinct malar stripe. Dark individuals typically have a uniformly gray-brown head and back, and heavy dark streaking below. Considering the variation which exists, some believe that the dark and gray forms are simply extremes of a gradient. As a general rule, colour varies from dark gray in Alaska to light gray in the eastern Arctic and white in Greenland. In all colour morphs, juveniles are noticeably browner and have an overall darker appearance. Furthermore, adults can be told apart from juveniles by the colour of the skin on the feet, eye-ring, and cere: yellow to orange on adults, and bluish-gray on juveniles, as is the case with peregrines.

In most areas, the Gyrfalcon’s diet is primarily birds, . Some gyrfalcons also hunt mammals quite extensively, focusing on lemmings, hares, and ground squirrels. Two main hunting approaches are used. The passive method is to perch on an outcrop, watch for prey, then dive toward it. More commonly, they use an active "contour-hugging" approach, in which they fly low over the ground, surprising prey at close range, then pursuing it over sometimes long distances. Typically the gyrfalcon flies with slow, deep, powerful wingbeats which give it a rapid level flight; on occasion it may hover briefly while searching for prey.

By mixing our Gyrs of Newfoundland origin with our Anatum or Peales Peregrine we blend the largest with the fastest falcons.

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