174 KEY TO THE BIRDS OF EASTERN NORTH AMERICA. 



Section 7. Fourth primary, longest; four or five outer 

 primaries, emarginate or notched ; tarsus, entirely 

 feathered ; upper tail coverts, not white. 



Thighs, tawny, more or less streaked or. barred 



American Rough-legged Hawk. 



Archibuteo lagopus sancti-johannis. 

 See No. 281. 



General plumage, sooty brown or black (black plumage). 



American Rough-legged Hawk. 

 Archibuteo lagopus sancti-johannis. 



See No. 281. 

 Thighs, tinged with deep rufous with numerous bars. 



Ferruginous Rough-legged Hawk. 

 Archibuteo ferruginous. 



See No. 282. 



Section 8. Fourth primary, longest ; three outer primaries, 



emarginate or notched. 



Tarsus, partly feathered; throat, white (adult) ; throat, tawny or buff (immature). 



Swainson's Hawk. 

 Buteo swainsoni. 

 See No. 277. 



Group 6. Wing, 17 to 21 inches long. 



Section 1. Third primary, longest; tarsus, wholly 



feathered. 



Basal portion of inner web of primaries, largely white, without bars ; thighs, 

 tawny or buff, more or less barred ; tarsus, thickly feathered. 



American Rough-legged Hawk. 



Archibuteo lagopus sancti-johannis. 

 See No. 281. 



Basal portion of inner web of primaries, largely white, without bars ; thighs, 

 tinged with deep rufous heavily barred. 



Ferruginous Rough-legged Hawk. 



Archibuteo ferrugineus. 



See No. 282. 



