swainson's hawk. 208 



BUTEO SWAINSONI Bonap. 

 146. Swainson's Hawk. (342) 



It is hardly possible, within the limited space at my disposal, to give any- 

 thing like a detailed description of the various phases of plumage which this. 

 interesting Buzzard assumes, according to age, sex, or the season of the year. 

 Suffice it to say, that individuals differ so much from one another as to have led 

 to the description of about a dozen different individuals as new species, all of 

 which are now attributable to Buteo mvainsoni. 



In measurement, this species is about the same as its nearest relative, the 

 Red-tail, averaging about 20 inches in length by about 50 in extent, but it is 

 less stoutly built, has the wings longer and more pointed, and has only three of 

 the primaries emarginate, whereas the Red-tail has four. The entire upper 

 parts are dark brown, many of the feathers with tawny edgings, those on the 

 head showing white when disturbed. Tail feathers, ashy-gray, crossed with 

 numerous dark bars, and tipped with yellowish white; upper tail coverts, 

 chestnut and white, with blackish bars ; under parts, white, more or less shaded 

 with chestnut. A broad pectoral area of bright chestnut, usually with a 

 glaucous shade, and displaying sharp black shaft lines; this area contrasting 

 strongly with the pure white throat. 



In the younger birds, the upper parts are much as already described ; the 

 lower parts, including the lining of the wings, are nearly uniform fawn color, 

 thickly spotted with blackish-brown. These large dark spots, for the most 

 part circular or guttiform, crowd across the fore breast, scatter on the middle 

 belly and tibise, and are wanting on the throat. In all stages of plumage the 

 iris of the eye is brown. 



Hab. — Western North America, from Wisconsin, Illinois, Arkansas and 

 Texas to the Pacific coast; north to the Arctic Regions, and south to Buenos 

 Ayres. Casual east tg Massachusetts. 



Nest, in a tree, at a height varying from ten to forty feet from the ground. 



Eggs, two to four, greenish-white or bufiy- white, often stained or blotched 

 with rusty -brown. 



Dr. Coues gives an admirable history of this species in his " Birds 

 of the North-West " (page 356), from which I shall here make a few 

 extracts : 



" This large Hawk is very abundant in Northern Dakota, where 

 it came under my almost daily observation during the summer of 

 1873." "Swainson's Buzzard may be seen anywhere in the region 

 mentioned — even far out on the prairie, miles away from the timber, 

 circling overhead, or perched on the bare ground. In alighting, it 

 generally takes advantage of some little knoll commanding a view 

 around, though it often has no more prominent place than the heap 

 of dirt from a badger's hole, from which to cast about for some 

 imprudent gopher espied too far from home, or still more ignoble 

 game." 



