FALCONS, HAWKS, EAGLES, ETC. 



163 



mainly within the country inhabited by meadow mice, and at the 

 season when they are at their worst eating the roots of the crops 

 and gnawing the bark of fruit-trees under the snow he devotes 

 himself to their destruction. 



Dr. Fisher says that the rough-leg is one of the most nocturnal of 

 our hawks, and that it "may be seen in the fading twilight watch- 

 ing from some low perch, or beating with measured, noiseless flight, 

 over its hunting ground." 



Subgenus Brewsteria. 



FERRUGINOUS ROUGH- 



348. Archibuteo ferrugineus (Licht.). 

 LEG : SQUIRREL, HAWK. 



Adults, normal phase : under parts white, sometimes slightly streaked 

 with brown ; upper parts and flanks reddish 

 brown ; tail white, more or less stained with 

 reddish brown, and sometimes marked with 

 a subterminal band. Adults, melanistic phase : 

 tail normal ; upper parts chocolate brown, 

 marked with rusty ; under parts rusty and 

 chocolate. Young : upper parts grayish 

 brown, feathers edged with rusty or yellow- 

 ish brown ; flanks white, more or less spotted 

 with dusky ; tail whitish for basal third, the 

 rest brownish gray, usually with several 

 more or less distinct dark bands. Male : 

 length 22.50, wing 15.90-17.00, tail 9.50- 

 10.50. Female : length 24, wing 17.00-18.80, 

 tail 10.50-11.00. 



Distribution. From the eastern Dakotas 

 and Texas to the Pacific, and from the Sas- 

 katchewan to northern Mexico ; casually to 

 Illinois. 



Nest. Of sticks and herbage, lined with 

 softer materials. Eggs: 2 to 5, creamy or 

 pale greenish, irregularly blotched with dif- 

 ferent shades of brown and lavender. 



Food. Almost exclusively small mam- 

 mals and reptiles, but also crickets. 



"The squirrel hawk is preeminently a bird of the prairie, and, 

 unlike the common rough-leg, shows little partiality to the vicinity 

 of water, though in other respects it closely resembles the latter 

 bird in habits. When this hawk is hunting its flight appears la- 

 bored and heavy, but when circling high in the air its flight is 

 graceful, and resembles closely that of the golden eagle. In fact, in 

 parts of the west it is known by the name eagle." (Fisher.) 



GENUS AQUILA. 



349. Aquila chrysa'etos (Linn.}. GOLDEN EAGLE. 



A bird of great size, robust form, and powerful physique. Tarsus closely 



Biological Survey, U. S. Dept. 

 of Agriculture. 



Fig. 232. 



