NORTH AMERICAN BIRDS. 177 



2d of June, 1886; it was in a mesquite bush, eight feet from the 

 ground. This is doubtless late nesting, as all other nests found were 

 empty. 



Three sets of two eggs each are in Mr. Norris' collection ; one 

 taken May 2, 1884, near Corpus Christi, measures 2.20x1.80,2.19x1.80; 

 their color is light grayish, faintly and sparingly spotted with light 

 drab; another collected in the same locality March 24, 1886, one egg of 

 which is unmarked, and the other faintly spotted with fawn color at 

 the large end ; sizes, 2.17 x 1.77, 2.25 x 1.78 ; the third set was taken on 

 the Arkansas river, Texas, April 2, 1888; they are dull grayish-white, 

 faintly and sparingly marked with light fawn color ; sizes, 2.33 x 1.65, 

 2.30x1.73. 



342. Buteo swainsoni BONAP [442.] 



Swainson's Hawk. 



Hab. Western North America from the Mississippi Valley to the Pacific ; north to the Arctic regions 

 and south to Buenos Ayres. Casual in New England. 



One of the commonest and most characteristic of the large Hawks 

 in various places of the West. Many are killed, as they commit great 

 depredations in the poultry yards ; their food, however, consists largely 

 of birds and the smaller quadrupeds squirrels, gophers, rats, mice, etc. 

 The flight of Swainson's Hawk is usually slow, but in pursuit of its 

 prey its swiftness is said to remind one of the dash of Accipiter velox, 

 Sharp-shinned Hawk. The sites which are chosen for nesting places 

 by this Hawk are extremely variable ; in some localities the nest is 

 built on the ground, on bushes, small saplings and on the ledges of 

 rocky cliffs. Old nests of hawks and crows are fitted up for the occa- 

 sion ; but usually it is built in the tallest trees and in an almost inac- 

 cessible position in the outer branches. 



Mr. L. Jones states that in Iowa this bird, while breeding, is found 

 principally in moderately timbered tracts, selecting less inaccessible 

 places for its nests than Buteo borealis, but of the same position and 

 composition. The eggs are deposited as late as May 15, usually May i. 



Mr. A. M. Shields took a set of two eggs of this Hawk, May 21, 

 1886, in the vicinity of Los Angeles, California, from a nest situated 

 in the extremity of the branches of an oak tree, fully fifty feet from 

 the ground; these are in my cabinet and measure 2.00x1.61, 2.2OX 

 1.67. The eggs of this Hawk are two to four in number, greenish- 

 white, buffy-white or colorless, sometimes unmarked, but usually 

 spotted, stained or blotched with reddish or rusty-brown. Their aver- 

 age size is 2.2ix 1.70. 



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