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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). 
Figuro 3. Feathered log of Rough-leg and Golden Eagle. 
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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, 
