162 



FALCONS, HAWKS, EAGLES, ETC. 



Beetles and grasshoppers are caught by them on the wing, and 

 twigs for their nests are broken off as they fly rapidly by. 



GENUS ARCHIBUTEO. 



General Characters. Like Buteo, but tarsus feathered in front and on 

 sides down to base of toes ; wings long-, four or five quills emarginate on 

 inner webs. 



KEY TO SPECIES. 



1. Bill small and weak, gape across corners of bill only 1.35-1.45. 



sancti-johannis, p. 162. 

 1'. Bill larger and stronger, gape across corners of bill 1.70-1.90. 



ferrugineus, p. 163. 



347a. Archibuteo lagopus sancti-johannis (GmeL). ROUGH- 

 LEGGED HAWK. 



Adults, normal phase. Under parts varying from whitish to yellowish 

 brown, more or less spotted with blackish, most heavily on breast ; upper 

 parts grayish brown or dark brown, streaked 

 with white and reddish brown ; tail with base 

 and upper coverts white and end with subter- 

 minal dusky band ; wing quills with outer webs 

 silvery gray. Young, normal plumage : similar 

 to adults, but end of tail plain grayish brown, 

 the basal part plain whitish ; under parts whit- 

 ish or buffy, crossed on belly by a broad belt 

 of uniform dark brown. Melanistic phase in 

 both young and old connected with normal 

 plumage by every variety of intermediate char- 

 acter entirely deep black except for white 

 forehead, white on inner webs of quills above 

 eniargination, and narrow broken bands across 

 base of tail. Male: length 19.50-22.00, wing 

 J 15.75-16.80, tail 9-10. Female : length 21.50- 

 _ '^ 23.50, wing 16.15-18.00, tail 9-11. 



From Biological Survey, u.S.Dept. Remarks. The white upper tail coverts 

 of Agriculture. an( j j ar g e s j ze are g. OO( j fi^ characters. 



Fig. 231. Distribution. Whole of North America 



north of Mexico, but breeding almost wholly north of the United States. 



Nest. Made of large sticks lined with grass, leaves, or feathers, in trees 

 or on cliffs. Eggs : 2 to 5, greenish white, fading to dingy white, irregu- 

 larly marked with blotches of brown and sometimes lavender. 

 Food. Principally small rodents, such as mice and lemmings. 



The rough-legged hawk is known mainly as a winter bird in the 

 United States, coming down with the fall migrants and spreading 

 over the country where he can find food to suit his taste, often 

 remaining all winter in the northern states where the deep snow and 

 intense cold drive less hardy species away. Where trappers are at 

 work he finds plenty of food in the freshly skinned or frozen bodies 

 of muskrats and other fur mammals left lying by the streams and 

 lakes ; but he is not dependent upon such supplies. He keeps 





