FALCONS, HAWKS, EAGLES, ETC. 



159 



irom Biological Sin \ r\ , U. S. 



Dept. 01 Agriculture. 



Fig. 230. 



342. Buteo SWainsoni Bonap. Swainson Hawk. 



Adult male in normal plumaye : throat and belly white, white of throat 

 sharp! 1/ contrasted ivith reddish brown chest band ; upper parts nearly uni- 

 form dark grayish brown ; tail crossed by 

 about 9 or 10 narrow blackish bands. Adult 

 female in normal plumage: like male, but 

 chest patch g-rayish brown instead of rufous. 

 Melanistic phase, both sexes : whole plumag-e 

 uniform sooty brown, under tail coAerts some- 

 times spotted or barred with rusty or whitish. 

 Every possible gradation is shown by different 

 individuals between this black phase and the 

 light colored normal plumage. Young : upper 

 parts blackish brown varied with buffy or yel- 

 lowish brown ; head, neck, and under parts 

 buffy brown, head and neck streaked Avith 

 blackish ; under parts usually more or less 

 blotched with blackish. Male: length 19.50- 

 20.00, extent 48.00-50.r)0. win^ 14.40-16.00, 

 tail 8-9. bill .80-.90. Female: length 21-22, 

 extent ."jO..5O-56.00, wing 14.75-17.25,tail 9-10, 

 bill .80-.9."). 



Distribution. — From the arctic regions 

 south to Argentina ; in the United States 

 from the Pacific to Wisconsin, Illinois, and 

 Arkansas ; casually to Massachusetts. Migratory north of South Dakota 

 and Nebraska. 



Nest. — In cottonwoods and other trees, and also in bushes and on rocks, 

 made of sagebrush. willoAv. or other sticks, lined largely with green leaves 

 and bark. Eggs : 1 to 4. greenish white, fading to yellowish, spotted in- 

 conspicuously with different sliades of brown. 



Food. — Almost entirely small rodents, principally striped gophers and 

 mice, together with grasshoppers and crickets. 



" On the arid wastes and tablelands of southern Arizona, as well 

 as in the sage and bunch grass districts of Nevada. Oregon, Washing- 

 ton, and Idaho, Swainson's hawk is especially abundant, outnumber- 

 ing, perhaps, all the other Kaptores of these regions combined. It is 

 eminently a prairie bird, shunning the densely timbered mountain 

 regions, and being more at home in the sparingly wooded localities 

 usually found along tlie watercourses of the lowhinds. 



"Compared witli the majority of our hawks it is gentle and un- 

 suspicious in disposition, living in perfect harmony with its smaller" 

 neighbors. It is no unusual sight to find other birds, . . . nesting 

 in the same tree ; and the Arkansas kingbird goes even farther than 

 this, sometimes constructing its home . . . under the nest of these 

 hawks or in the sides of it. . . . 



"The food of Swainson's hawk consists almost entirely of the 

 smaller rodents, principally striped gopliers and mice, as well as grass- 

 hoppers and the large l)lack cricket, winch is very common as well as 

 destructive in certain seasons, and the bane of the farmers in eastern 



