Distribution

Figure 1. Breeding and wintering range of the Gyrfalcon.

The Americas

Breeding Range

Figure 1. From approximately 79°N to 60°N, locally to 55°N (Cade 1982, Brodeur et al. 1995); formerly south to 51° 28’ N at entrance to Bras d'Or River (now Brador), Quebec (Audubon 1897, Todd 1963, Brodeur et al. 1995). In Canada, breeds on most Arctic Islands and the Arctic coastal plain (Fyfe and Grier 1972, Shank and Poole 1994), N. British Columbia, Yukon (Platt 1976, Mossop and Hayes 1994), se. Northwest Territories (Kuyt 1980), and n. Quebec and Labrador (Todd 1963). Summer sightings in Long Range Mountains of Newfoundland suggest breeding there (L. Tuck, pers. comm.). Most of Alaska except north coastline, w. Aleutians, Cook Inlet, central interior, and se. Alaska (Cade 1960, White and Cade 1971, Swem et al. 1994, Gibson and Byrd 2007).

Winter Range

Winter status on breeding range poorly documented, but available information (Cade 1960, Platt 1976, Salter et al. 1980, Norment 1985) suggests most birds are resident, at least below 70°N. Regular winter visitor to British Columbia, Alberta, Saskatchewan, and Ontario (Bromley 1986, Wiseley and Pinel 1987). Most winter records are above 40°N (Am. Ornithol. Union 1983, Butcher et al. 1987) and are of immature birds. Extreme southerly records from central and n. California (Small 1994), Texas (Lockwood et al. 2002), and North Carolina (Holmes and Fuller 1995).

Many published sources indicate Gyrfalcon does not winter regularly south of U.S.-Canada border (e.g., Root 1988, Schmutz et al. 1991), but much evidence suggests this is not the case with significant numbers of sightings in northern tier states (Platt 1976, Dobler 1989, Sanchez 1993, Flann 1998), establishment of fixed winter ranges (Dobler 1989, Sanchez 1993), and evidence that birds may repeatedly return to same wintering area (Palmer 1988, Sanchez 1993). Hence, the Gyrfalcon should be considered a regular, but uncommon winter visitor to the n. U.S.

Outside The Americas

Breeding Range

Coastal Greenland to 82°N (Salomonsen 1950, Burham and Mattox 1984), Iceland (Nielsen 1986), Norway, Sweden, Finland (relatively rare in n. Europe, Cramp and Simmons 1980), n. Russia, Siberia, and Kamchatka to below 55°N (Dementiev and Gladkov 1951, Ellis et al. 1992, Cade et al. 1998, Potapov and Sale 2005).

Wintering Range

South irregularly into central Europe and Asia (Dementiev and Gladkov 1951, Glutz von Blotzheim et al.1971, Potapov and Sale 2005).

Historical Changes

None documented in Nearctic breeding distribution, except for s. coast of Labrador and adjacent Quebec. Although significant increase in winter sightings (Christmas Bird Count records) from early 1970s to early 1980s may only be due to new awareness among birdwatchers that Gyrfalcon does winter in s. Canada and n. U.S. (Butcher et al. 1987), it may also reflect this species’ increasing occurrence around human-made reservoirs where waterfowl concentrate in winter (Sanchez 1993).

Fossil History

Three late Pleistocene (Rancholabrean North American Land Mammal Age, <400,000 Megannum) records for Gyrfalcon are earliest for species in North America. Two are records from cave deposits in Wyoming: Bell Cave, Albany Co. (Walker 1974) and Little Box Elder Cave, Converse Co. (Emslie 1985). Emslie suggests that several immature bones from Little Box Elder are evidence that Gyrfalcon may have nested in Wyoming during late Pleistocene. Mammalian faunas associated with bird fossils from Bell and Little Box Elder Caves reflect a colder climate. Third record is fossil species Falco swarthi (Miller 1927), which Emslie (1985) regarded as being essentially identical to Gyrfalcon. There are other Pleistocene records in Europe (Sweden, Czechoslovakia, Hungary; Brodkorb 1964, and the Iberian Peninsula; Baltar and Carrasquilla 1993). Dove et al. (2005) discovered ancient Gyrfalcon feathers in melting alpine ice patches in Southern Yukon. Though age of the feathers was not determined, other bird feathers found at the site were radio-carbon-dated as early as 4500 BP.