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FALCONID^, DIURNAL BIUDS OF PREY. GEN. 161, 162, 163, 164. 219 



161. Genus ONYCHOTES Ridgway. 



Gruber's Buzzard. "Nostrils nearly circular, with a couspicuous (not 

 central) tubercle ; tarsus very long and slender ; toes moderate ; claws 

 very long, strong and sharp, but only slightly curved; tibial feathers short, 

 close, not reaching beyond the joint; wing very short, much rounded, 

 and very concave beneath ; 4th quill longest, 1st shorter than 9th ; tail 

 moderate, rounded ; outstretched feet reaching beyond tail." N"o white 

 about head or neck ; general color dark bistre-brown, darkest on crown and 

 back, below paler and more rusty ; primaries uniform black above, below 

 showing white basally ; tail crossed by 7-8 obscure narrow dark bars ; 

 wing 10; tail 5f ; tarsus 2f. One specimen known, supposed to come 

 from California. Ridgway, Proc. Phila. Acad. 1870, 149. . gruberii. 



162. Genus PANDION Savigny. 



Osj)re>/. FisJt Haiuh. Plumage lacking aftershafts, compact, imln-icated, 

 oily, to resist water; that of the legs short and close, not forming the 

 flowing tufts seen in most other genera, that of the head lengthened, 

 acuminate ; primary coverts stiff and acuminate. Feet immensely large and 

 strong, the tarsus entirely naked, granular-reticulate, the toes all of the same 

 length, unwebbed at base, very scabrous underneath, the outer versatile ; 

 claws ver}^ large, rounded underneath. Hook of the bill long ; nostrils 

 touching edge of the cere. Above, dark brown ; most of the head and neck, 

 and the under parts, white, latter sometimes with a tawny shade, and streaked 

 with brown. 2 feet long ; wing 18-20 inches ; tail 8-10. Temperate North 

 America, abundant; migratory, piscivorous. Wils., v, 13, pi. 37; Nutt., 

 i, 18; AuD., i, 64, pi. 15; Cass, in Bd., 44; Coop., 454. . haliaetus. 



163. Genus AQUIIiA Auctorum. 



\ 4 / Golden Eagle. Tarsus completely feathered. Dark brown with a pur- / 

 plish gloss; lanceolate feathers of head and neck, golden-ljrown ; quills 

 blackish; in the young, tail white, with a broad terminal black zone. 

 About 3 feet long; wing upward of 2 feet; tail a foot or more. North 

 America, rather northerly, in winter south ordinarily to about 35°. Wils., 

 vii, 13, pi. 55, f. 1; Nutt., i, 62; Auo., i, 50, pi. 12. A. canadensis 

 Cass, in Bd., 41 ; Coop., 449 ciirysaetus. 



164. Genus HALIAETUS Savigny. 

 'l^l^ Bald Eagle. Tarsus naked. Dark brown ; head and tail white after the ^/' 

 third year; before this, these parts like the rest of the plumage. About 

 the size of the last species. Immature birds average larger than the adults ; 

 the fiinious "Bird of Washington" (Aud., Oru. Biog., i, 58, pi. 11, and B. 

 Amer., i, pi. 13, Kentucky) is a case in point. North America, common; 

 piscivorous ; a jjiratical parasite of the osprey ; otherwise notorious as the 

 emblem of the Republic. Wils., iv, 89, pi. 36 ; vii, pi. 55 ; Nutt., i, 72 ; 

 Aud., i, 57, pi. 14; Cass, in Bd., 43; Coop., 451. . . leucocephalus. 



