478 BIRDS OF ILLINOIS. 



1. A. lagopus sancti johannis. Bill comparatively narrow at the base and compressed 

 terminally. Tarsus not more than 3 inches. Breast never immaculate white; no 

 rufous on upper parts or tibiae. Adult: Tail with several bands. Light phase 

 with white prevailing, this much broken however, by dusky spotting, the spots 

 rather coalesced on pectoral region. Melanistic phase sometimes uniform coal- 

 black (more commonly dark brownish), with white lores, white under side of 

 quills, and light (grayish or white) narrow bands on tail, Young: Terminal half 

 (or less) of toil grayish brown, without bars, basal portion white (usually unvaried). 

 Light phase grayish brown above, with dusky streaks and fulvous or buffy edg- 

 ings; beneath ochraceous or buffy whitish, the belly and flanks usually dark 

 brownish; breast streaked with brown. Melanistic specimens blackish brown, 

 sometimes nearly uniform, but usually more or less streaked with fulvous edg 

 ings to the feathers. Male: Wing, 15.75-16.80; tail, 9.00-10.00; tarsus, 2.75-2.80; 

 Female: Wing, 16.15-18. 00; tail. 9. 00-11. 00; torsus, 2.80-3.00. 



. A. ferruginous. Bill very broad, and somewhat depressed, at the base, the gape 

 almost "flssirostral." Tarsus more than 3 inches. Breast usually immaculate 

 white (rufous in melanistic specimens); upper parts and tibiae rich rufous in 

 adults. Adult, light phase: Upper parts and tibiaa fine rufous, the former with 

 tear-shaped stripes, or spots, the latter with transverse bars of dusky. Tail white 

 washed with ashy, and more or less stained with light rufous. Melanistic phase: 

 Prevailing color deep chocolate-brown, more or less varied with rufous; tail as 

 in the light phase. Young, light phase: Above grayish brown, the feathers edged 

 with ochraceous or fulvous; tibiae white, usually more or less barred with dusky; 

 tail white only on basal portion and on inner webs, the terminal half (or more) 

 grayish brown, usually with several more or less distinct darker bars. Male: 

 Wing, 15.90-17.00; tail, 9.50-10.50; tarsus. 3.10-3.45. Female: Wing. 17.00-18.80; tail. 

 10.50-11.00; tarsus.3.20-3.40. 



Archibuteo lagopus sancti-johannis (Gmel.) 



AMERICAN BOUGH-LEGGED HAWK. 

 Popular synonyms. Black Rough-leg; Black Hawk. 



Falco sancti-johannis GMEL. S. N. i, 1788, 273. AUD. Orn. Biog. ii, 1831, 381. 

 Buteo sancti-johannis Cuv. 1817. NUTT. Man. i,1832. 98. 

 Archibuteo sancti-johannis GKAT, 1849. CASS. in Baird's B. N. Am. 1858, 33. BAIBD. 



Cat. N. Am. B. 1859, No. 31. 

 Archibuteo lagopus var. sancti-johannis COUES, Key, 1872, 218; Check List, 1874, No. 



356; B. N. W. 1874,361. B. B. & R. Hist. N. Am. B. iii, 1874, 304. 

 Archibuteo lagopus sancti-johannis RIDGW. Nom. N. Am. B. 1881, No. 447. COUES, 



2d Check List. 1882, No. 525. 

 Falco lagopus WELS. Am. Orn. iv, 1821, pi. 33, fig. 1 (nee BBUNN). AUD.B. Am. 1831, pis. 



166,422; Orn. Biog. ii, 1831, 277. 

 Buteo lagopus Sw. & RICH. F. B.-A. ii, 1831, 52. pi. 28. Nurr.Man. 1832.97.-AUD. B. Am. 



i, 1840, 46. pi. 11. 

 Archibuteo lagopus BP. 1850. CASS. in Baird's B. N. Am. 1858,32. BAIBD, Cat. N. Am. 



B. 1859, No. 30. 

 Falco niger WELS. Am. Orn. i, 1812, pi. 53, figs. 1,2. 



HAB. Whole of North America, breeding in arctic and subarctic districts. (The true 

 A. lagopus occurs in western Alaska.) 



a. Normal plumage. 



SP. CHAB. Adult male, (No. 43,073, Fort Resolution, June: J. Lockhart). Ground 

 color of the upper parts dull umber-cinereous, this more rufous on the shoulders, and 

 dull white on nape, scapulars, inner secondaries, and upper tail-coverts; rump entirely 

 black, feathers bordered with whitish. All the feathers above with central oblong or 

 irregular spots of black, this color predominating on top of head, and forming trans- 

 verse bands across the wing- coverts and secondaries; upper tail- coverts pure white 



