8 



MUSEUM BULLETIN NO. 28. 



distinction can be drawn between this hawk and the next species., 

 Swainson's Hawk, and it may often be confused with it except when it 

 has the red tail. When without this distinguishing mark, and in the 

 black phase, its slightly larger size and the shape of the first primary 

 wing feathers are the only reliable guides. In the Red-tail, the webs 

 of the four outer flight feathers of the wings are suddenly reduced in 

 size as though a shaving had been taken from their edges with a knife 

 (Figure I), whereas in Swainson's only three are so shaped (Figure 2). 



Figure 3. Feathered leg of Rough-leg and Golden Eagle. 



Both the Red-tailed and Swainson's Hawks can be told from the two 

 Rough-legs by their legs which are bare of feathers for some distance 

 above the base of the toes (compare with Figure 3). 



Swainson's Hawk (length 19|-22 inches) is slightly smaller than 

 the Red- tail though a large Swainson's measures close to a small Red- tail. 

 Many of the plumages of this bird match very closely some of those of 

 the Red-tail, but the most characteristic is brown above, cream below, 



