HAWKS AND EAGLES. 375 



blurred. I have been surprised to observe how easily, when 

 guiding themselves among the trees, they detect the presence 

 of a Partridge or squirrel. They are not, however, capable of 

 constant activity, and occasionally, gracefully sailing up to 

 some perch, they watch for their prey, sometimes doing so in 

 open land. They stand with an erectness observable in other 

 Hawks, and are spirited even when at rest. 



d. For a greater part of the year they live singly and 

 silently, but in spring I have heard them utter loud screams. 



V. BUTEO. 



A. BOREALIS. Red-tailed Hawk (or Buzzard). (East- 

 ern) " Red-tail. " " Hen Hawk" In Massachusetts, a resi- 

 dent throughout the year, but less common than the next 

 species.* 



a. Extreme length, nearly two feet. Above, dark brown, 

 marked with fulvous (chiefly on the head), and with white 

 (chiefly behind). Tail, chestnut-red, tipped with white, and 

 sub-tipped with black, but beneath of a uniform silvery gray. 

 Under parts, white (or tinged), marked with a varying shade 

 of brown, which generally forms an interrupted band across 

 the lower breast. A fine immature specimen, now before me, 

 is more than two feet in length. Above, dark umber, more 

 or less interrupted by white, chiefly on the tail-coverts. Be- 

 neath, white ; sides blotched with umber brown, forming a 

 dark zone across the lower breast. Feathers of the thigh 

 spotted or imperfectly barred with a lighter shade. Tail, 

 medium brown (often tinged with gray, but here with chest- 

 nut), barred with blackish, tipped with whitish; beneath, 

 light gray, and faintly barred. 



b. The nest does not differ from that of the Red-shouldered 

 Hawk, unless in being sometimes less well lined, occasionally 

 rather less accessible, and more often built in dry woods. 

 For a description of the eggs, see B, b. 



* The Red-tailed Hawk breeds spar- tions, when it is sometimes very numer- 



ingly and somewhat locally through- ous. It occurs commonly in winter, 



out New England, but at most places also, in Massachusetts and to the 



it is oftenest seen during the migra- southward. W. B. 



