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. 1C2. 
1'. Bill larger and stronger, gape across corners of bill 1.70-1.90. 
ferrugineus, p. 163. 
347a. Archibuteo lagopus sancti-johannis ( Gmd .). Rough- 
LiEgged 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 huffy, crossed on belly by a broad belt 
of uniform dark brown. Melanistie 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 
emargination, and narrow broken bands across 
base of tail. Male: length 19.50-22.00, wing 
15.75-10.80, tail 9-10. Female : length 21.50- 
23.50, wing 16.15-18.00, tail 9-11. 
Remarks. — The white upper tail coverts 
and large size are good field characters. 
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 rougli-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 
V "• ^ ** \ 
From Biological Survey, U. S. Dept, 
of Agriculture. 
Fig. 231. 
