288 HAWKS, EAGLES, AND KITES 



Falconidce. Of the former, twenty-two species are North American. 

 These present much diversity of form and habit, but our eastern species 

 of the genera Buteo and Accipiter may, in the Northern States, at least, 

 be seen during the migratory seasons, traveling in scattered flocks, which 

 may take hours to pass a given point. At other times of the year, with 

 few exceptions, they are solitary birds, having no intercourse with their 

 kind. During the breeding season many species have definitely bound- 

 ed haunts, upon which intrusion by individuals of the same species 

 is not permitted. With much regularity they return to the same locality 

 and even the same nest year after year, and some species are known to 

 mate for life. Their days are an unceasing vigil. At all times they are 

 on the alert for food. With the Buteos this consists to a large extent of 

 small mammals and insects, birds and poultry forming a compara- 

 tively insignificant part of the diet of most species. Most Hawks are 

 thus of great value to the agriculturist as the natural check upon the 

 increase of the myriads of small rodents so destructive to crops. 



The cries of Hawks are generally loud, startling, and characteristic 

 of their fierce natures. They strike their prey with their feet, and use 

 the bill to tear it into fragments. 



Hawks' nests are generally bulky affairs, composed of coarse twigs 

 and sticks. The presence of downy feathers gives evidence that they 

 are or have been recently occupied. The young are hatched with a 

 scanty growth of white down which soon covers the body. 



To facilitate identification in the field, the Hawks of this and the 

 following families (Falconidce, Pandionidce) have been placed in one 

 key as below. 



KEY TO THE SPECIES 



I. Wing over 19'00. 



A. Upper half of tarsus feathered. 



a. Whole head and neck white 352. BALD EAGLE (Ad.). 



b. Head or neck brown or brownish. 



6 1 . Bill mostly yellow (Greenland). . 351. GRAY SEA EAGLE (Ad.). 



6 2 . Bill black or blackish 352. BALD EAGLE (Im.). 



B. Whole tarsus feathered 349. GOLDEN EAGLE. 



II. Wing under 19'00. Placed in three sections as follows: 



1. Underparts more or less streaked and spotted, without cross-bars. 



2. Underparts with more or less numerous cross-bars. 



3. Underparts without streaks or bars. 



1. Underparts more or less streaked and spotted, without crossbars. 



A. Outer primary with numerous black or blackish bars. 

 a. Wing under lO'OO. 



a 1 . Back bright rufous, with or without black bars. 



360. SPARROW HAWK. 



a 2 . Back bluish slate-color .... 357. PIGEON HAWK (Ad.). 

 a 3 . Back fuscous, second primary longest. 



357. PIGEON HAWK (Im.). 



a 4 . Back fuscous, fourth primary longest, tail-feathers of nearly equal 

 length; wing under 9'00 . 332. SHARP-SHINNED HAWK. . (Im.) 

 a 6 . Back fuscous, fourth primary longest, outer tail-feathers half 

 an inch or more shorter than the middle ones; wing over 9'00. 



333. COOPER'S HAWK (Im.) . 



