142 HOW TO STUDY BIRDS 



toward the woods, but usually so far away that it 

 seems hopeless to the beginners to distinguish them. 

 Yet most of them can be recognized in an instant, 

 even at quite long range, especially with the aid of 

 the field-glass. In Eastern districts there are two 

 large kinds commonly called " hen-hawks," — the red- 

 tailed and red-shouldered hawks. The former Is a 

 little more heavily built and has whitish underparts 

 with a few darker markings on the breast; in the 

 adult phase the upper side of the tail is of a uniform 

 chestnut-red color, which can be detected as the bird 

 wheels in the air and the sunlight strikes it. The 

 red-shoulder, besides having a slight rufous color on 

 the " shoulder " of the wing, has the under-parts of 

 a much darker hue than the red-tail, brownish and 

 heavily marked, and the tail banded with alternate 

 black and white. The Immature red-tail has a 

 banded tail, but with fewer bands, and its light under- 

 parts are characteristic. Both these species soar and 

 circle a good deal In flight, and are also seen perching 

 motionless on isolated trees, especially the red-tail. 



Another hawk with almost equal spread of wings 

 but of more slender build Is the marsh hawk, distin- 

 guished by the conspicuous white spot on the rump. 

 This variety generally flies rather low, quartering 

 over swampy land. In winter another large hawk 

 with white on the rump Is occasionally seen about 

 open land, the American rough-legged hawk, a slug- 

 gish bird, as large as the red-tail, feathered to the 

 toes. The osprey, or fish hawk, has white under- 



