Falco gyrfalco, Linn. Syst. Nat. i. p. 130 (1766) ; Naum. xiii. taf. 391 ; Gould, B. of Gt. B. i. pl. 16 ; Newton, Ooth. Wolley, p. 87, pl. viii. tab. C. ; (Sharpe), Cat. B. Br. Mus. i. p. 416 ; Dresser, vi. p. 15, pl. 367 ; Saunders, p. 345 ; Lilford, i. p. 29, pl. 15 ; F. rusticolus gyrfalco, Ridgway, p. 246.
Jagdfalke, German ; Jagtfalk, Dan., Norweg., and Swed. ; Riefsakfalle, Lapp. ; Tunturivalli, Finn. ; Krechet, Russ.
Male ad. (Norway). Upper parts dark slate-grey barred with light blue grey, in some places nearly white ; head blackish grey with whitish markings on the nape and sides of the neck ; rump and upper tail-coverts clear blue-grey barred with slate-blue ; quills dark brown externally mottled with grey, the inner webs white with dark bars ; tail slaty brown barred with blue-grey and tipped with white ; a broad moustachial stripe slaty brown ; under parts white, the breast and abdomen with dark drop¬shaped stripes, the flanks and under tail-coverts barred with slaty brown ; bill blue, becoming black towards the tip ; cere, edge of eyelid, and feet yellow ; iris nearly black. Culmen 1.35, wing 13.6, tail 8.5, tarsus 2.4 inch. Female similar but larger. The young bird has the head and neck buffy white striped with dark brown, the upper parts dark brown with buffy white margins, the under parts white, on the throat narrowly and other-wise broadly and closely striped with dark brown, sometimes so closely that scarcely any white is visible.
Hab. Northern Scandinavia and Lapland, rarely straying down to continental Europe ; has once or twice been obtained in England ; of doubtful occurrence in North Asia ; Arctic North America.
Inhabits rocky localities and is a bold powerful bird, swift on the wing, and when caught and trained highly esteemed for falconry purposes being docile and courageous. It feeds on small mammals, such as squirrels, lemmings, &c., and birds, especially Willow Grouse and Ptarmigan. Its nest,, which is constructed of sticks sparingly lined with grass, is placed on a rock or a tree, sometimes even on the ground, and in April or May 3 to 4 eggs are deposited, which are somewhat finer in texture of shell than those of F. islandus, and are so closely spotted or freckled with fox-red or reddish orange on a dull white ground that the ground-colour is often entirely obscured. In size they measure about 2.29 by 1.81.
757. Falco gyrfalco