The Ferruginous Rough-leg 



mens are more frequent upon the Pacific Coast than on the Great Plains. 

 The American Rough-leg is almost anything in plumage, from lightly 

 mottled brown to black, and its general appearance is exceedingly variable. 

 Dr. Cooper naively conjectured that the bird might breed "in the high 

 mountains" ; but later observations have failed to substantiate the claims of 

 the American Rough-leg to a place on the breeding list of any western state. 



No. 336 



Ferruginous Rough-leg 



A. O. U. No. 348. Buteo ferrugineus (Lichtenstein). 



Synonyms. — California Squirrel Hawk. Ferruginous Rough-legged 

 Buzzard. 



Description. — Adult, normal phase: Head above and on sides, back, wing- 

 coverts, and rump, mingled blackish and chestnut-brown, each feather darker cen- 

 trally and edged with chestnut, the forehead and sides of head further edged or mingled 

 with white; primaries blackish with glaucous bloom on outer webs, shafts chiefly white, 

 and inner webs largely whitish; the remaining quills similar but more or less blackish- 

 and whitish-barred on inner webs; tail below silvery white, above mingled ashy and 

 ferruginous with white base and tip; head above and sides black-and-white streaked 

 in about equal amounts; underparts chiefly white, the chest lightly marked with 

 rusty; throat, neck, and breast with sharp blackish shaft-streaks; flanks, flags, and 

 tarsi strongly tinged with rusty red and marked with blackish; also more or less marking 

 of chestnut on belly and sides. Adults, melanistic phase: Above rich chocolate brown; 

 below mingled with rusty and chocolate; tail unchanged. Bill dark bluish; feet and 

 cere yellow; irides light brown or yellow. Immature: Upperparts grayish brown 

 (bister nearly) with tawny edgings; tail without rusty, white for basal third, remainder 

 grayish brown, crossed by several indistinct dusky bands; underparts nearly pure 

 white, not tinged with rusty posteriorly, but sparingly marked, as on sides of breast, 

 flanks, and shanks, with dusky. Adult male, length 571.5 (22.50); extent 1384.2 

 (54.50); wing 421.6 (16.60); tail 254 (10.00); tarsus 69.9 (2.75). Adult female, length 

 603.3 (23-75) : extent 1435 (56.50) ; wing 457.2 (1 8.00) ; tail 273. 1 (10.75) ; tarsus 85 (3.35). 



Recognition Marks. — Brant size; soaring flight or sluggish flapping; strong 

 mingling of rusty red above, distinctive in any adult plumage; white of underparts 

 shading to rusty posteriorly, of normal plumage, unique. 



Nesting. — Nest: A bulky platform of sticks on ledge or cliff, rarely in trees; 

 lined with fresh twigs and green branches, or variously. Eggs: 2 to 4; white, or green- 

 ish white, rarely immaculate, usually handsomely spotted and blotched, boldly or 

 obscurely, sometimes sprinkled, with soft reddish browns or rich rufous (Rood's brown, 

 cinnamon-brown, russet, hazel, carob-brown), and with undershell markings of vina- 

 ceous gray. Av. of 15 specimens in the M. C. O. coll.: 59.5 x 46.5 (2.34 x 1.83); index 

 78. Extremes: 55-65 by 42-51.2 (2.16-2.56 by 1. 65-2. 016). Season: April 25-May; 

 one brood. 



General Range. — Breeds in the Great Plains region of western North America 

 from northern Montana, southern Saskatchewan, and southern Manitoba, south to 

 Colorado and Kansas. Apparently the only authentic record of the nesting of this 



1698 



