Thursday, January 5, 2012

The Arctic Falcon

Gyrfalcons are the largest and most powerful falcons on our planet, inhabiting Arctic and Subarctic regions of the globe. Those that live near or above the Arctic Circle are white or pale gray in color while more southern subspecies have various degrees of gray or brown in their plumage.

Solitary for much of the year, adult males and females pair up in March and a clutch of eggs is laid by late April, usually on a bare rock ledge or perhaps in an abandoned raven nest. Both parents incubate the eggs and, within two weeks of hatching, the downy young are left to endure the harsh northern climate while the parents hunt for food; it is then that gyrfalcons are most vulnerable to predation, usually by ravens, skuas or Arctic fox. Those that survive to adulthood have little to fear from natural predators; swift, powerful and agile, they are imposing rivals and may live for 20 years or more.

Gyrfalcons feed primarily on ptarmigan but also attack geese, ducks, gulls and a variety of Arctic songbirds; tundra residents such as Arctic hares, ground squirrels and lemmings are also potential victims. These magnificent raptors, in the style of great white sharks, initially stun their prey with a traumatic collision or chase them to ground before making the kill. During the colder months, gyrfalcons are known to hunt along the pack ice, oblivious to the frigid conditions; though nonmigratory, a few may turn up across the northernmost U.S. in mid to late winter.