74 BIRDS OF PENNSYLVANIA. 



SUBOKDER FA LOOSES. FALCONS, HAWKS, EAG-LKS, ETC. 



FAMILY FALCONID-ffi. FALCONS, ETC. 

 SUBFAMILY ACCIPITRIN^I. BUZZARDS, HAWKS, ETC. 



GENUS CIRCUS. LACEPEDE. 

 331. Circus hudsonius (LINN). 



Marsh Hawk; Harrier; Bog-trotter. 



DESCRIPTION. (Plate 13.} 



Dimensions. Total length of female, 19 to 21 inches; extent of wings about 47 

 inches ; wing about 15 ; tail about 10 inches. Male smaller. 

 Hab. North America in general, south to Panama. 



The Marsh Hawk is quite plentiful during the spring and autumn 

 in Pennsylvania. Its nests and eggs are said to have been found in 

 the meadows near Philadelphia; .also in Delaware county, and like- 

 wise along the Susquehanna river. As a native it is rare in this 

 region. I have observed the Marsh Hawk only as a passing visitor, 

 most numerous in the fall; frequenting, during its sojourn with us, 

 the extensive and grassy meadow-lands, chiefly about the large 

 streams. In the mountainous portions of this State, as well as the 

 highlands, this bird is seldom met with. 



When flying this species can easily be distinguished from other 

 hawks by the white upper tail coverts, so conspicuous in the females 

 and immature birds, or those usually met with. The old male, rare 

 and seldom found in this section, can be recognized by the bluish-white 

 plumage. 



According to Mr. Gentry * the nest is commonly situated in the midst 

 of a swamp or a low meadow, where there is a dense growth of vegeta- 

 tion and is composed, externally, of small sticks, for a ground work, 

 on which is placed a superstructure of dried grasses, within which 

 there is sometimes, though rarely, a lining of feathers. The same 

 writer states that the eggs are four or five in number, and while the 

 eggs of the same nest seldom display any perceptible difference in 

 their markings, some specimens are a dull white with a greenish tinge, 

 and destitute of spots ; others have a bluish or greenish ground color, 

 with irregular blotches of light lilac or lavender. The eggs are de- 

 scribed as broadly oval in contour, with nearly symmetrical extrem- 

 ities and averaging 1.85 inches in length and 1.43 inches in width. 



FOOD. 

 Notwithstanding the fact that these hawks rarely, if ever, prey 



Life-Histories of the Birds of Eastern Pennsylvania. Vol. II. 



