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, inorc or less streaked or, )),irre(l 



American Rough-legged Hawk. 



ArchibiUeo layopus sancti-johannis. 

 See No. 281. 

 Gi-'nerul plumage, sooty l)ro\vn or lilack (black plum.age). 



American Rough-legged Hawk. 

 Archihnteo Ingopus sancti-johannif:. 

 See No. 281. 

 Thighs, tiuged with deep rufous with numerous bars. 



Ferruginous Rough-legged Hawk. 

 Arch ihutco ffrrugineiis. 



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. 



ButPO Kwainsoni . 

 See No. 277. 



Group 6. Wing, 17 to 21 inches long. 



Section 1. Third primary, longest; tarsus, wholly 



feathered. 



ISasal ]iortioii of iinicr web of jirimaries, largely white, without bars; thighs, 

 tawny or bull', more or less barred ; tarsus, thickly feathered. 



American Rough-legged Hawk. 



Archihnteo lagapus sanrti-johannis. 

 See No. 281. 



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

 tinged with d(;ep rufous heavily barred. 



Ferruginous Rough-legged Hawk. 



ArchilnUcn firniyineus. 



See No. 282. 



