258 AVES: RAPTORES. — XLI. 



hrown. L. IJ. W. 7. T. 6. N. Am.; ahundaiit ; a small hut 

 CDiira^i'Ous liawk. riio sjn'rit's of this genus an- more destructive 

 auionjj; poultry than any other hawks. (Lat., swift.) 



808. A. cooperi Bonaparte. Ciiickkn Hawk. Tail roiiiuicil ; 

 tarsus never Ixjoted ; eolors similar, more hlue, the toj) of licad 

 darker, the tail more plainly white tipped. L. 18. \V. 10. T. 8. 

 N. Am., common. (To Wm. Cooper, of New York.) 



aa. Tarsus foathered about half way down in front, the featliers scarcely sep- 

 arated behind. { Astur Laa-padti.) 



800. A. atricapillus (Wilson). (losiiAWK. Chiefly slate blue 

 with white superciliary strij)e ; lower parts white, finely barred 

 with brown; tail with four dark bars. L. 24. W. 14. T. 11. 

 Northern, S. to U. S. in winter. (Lat., black-haired.) 



421. BUTEO Cuvier. (Lat. buzzard, as these hawks are called 

 in Enjjland.) 



a. Outer web of primaries without white, bufly, or ochraceous spots. 

 b. Four outer primaries emargiiiate on iiuier wel). 



c. Head and neck uniform dark sooty brown, or streaked with white, 



never with buffy or reddish. 



810. B. harlani (Audubon). Black Hawk. Tail irregularly 

 mottled with grayish, rusty, white, or blackish and with a dark 

 band near tip ; general color usually very dark but vari.ible. L. 

 21. W. IG. T. 10. S. W., E. to 111., scarce (subsp. of no. 811). 



cc. Head and neck more or less streaked with ochraceous or rusty red. 



811. B. borealia (Gmelin). Hkn Hawk. Kkd-Tailkd Biz- 

 ZARD. Dark brown; much barred and streaked; tail in adult 

 bright chestnut red above, with a narrow black bar near its tip. 

 L. 2.3. W. 1.''4. T. s^. N. Am. common, replaced W. by var. 

 calurus Cassin, dark brown, sometimes uniform. 



bb. Three outer primaries cmarginate on inner web. {Tachytriorchit Kaup.) 



d. Wing more than 13. 



812. B. Bwainsoni Bonaparte. SwAixsox's Bi'zzard. Gray, 

 variously streaked, usually a bright chestnut or brownish area on 

 breast ; wings dusky ; tail with nine or ten narrow dark bars ; 

 variable. I.. 20. \V. 16. T. 8^. W. U. S., E. to lud. and Mass. 

 (To Wm. Swainson.) 



dd. Win),' less than 12. 



813. B. latiBsimuB (Wilson). BnoAn-W^lNOED Hawk. Brown 

 above, whitish or fulvous below, variously streaked and barred ; 

 conspicuous dark cheek patches ; tail with broad dark bands alter- 

 nating with narrower pale ones, white-tipped ; lower parts brownish 

 with whitish spots ; in young whitish with darker streaks. L. 18. 



