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THE RAPTORIAL BIRDS OF IOWA 



Fig:. 51. Rough-legged Hawks, dark 

 phase, male, above; light phase, fe- 

 male, below. 



Range. North America above Mexico; breeding north of the 

 United States, and wintering in most parts of the United States. 



The Rough-legged Hawk is a fairly common species throughout 

 the state during the late fall, winter and early spring months. 

 Through several years of observation I am confirmed in the belief 

 that they are more abundant in November, and again late in Febru- 

 ary and in the first half of March, than during the midwinter season. 



These hawks begin to appear with the early snows ; and, as the 

 ground becomes more deeply and continuously covered, they move 

 southward in the main, comparatively few remaining if the winter 

 be severe. 



When the spring thaws bring conditions similar to those of late 

 autumn, they return, but in numbers not so apparent, either because 

 they are more wary through experience with the nimrods of regions 

 farther south, or perhaps because a more rapid northward migration 

 gives us less time for observation. The majority of our specimens 

 of the Rough-leg secured in various parts of Iowa, have been taken 

 in November, and about two-thirds of them are of the dark or melan- 

 istic plumage. 



