128 OWLS. 



length, and its sides and belly are barred, not streaked, 



with blackish. It does not frequent marshes, but lives in 



swampy thickets or dense woods, and 



Long-eared Owl, ma k es i ts nest i n t } ie abandoned home 



Asia w^lson^anus. , 



of a Crow, Hawk, or squirrel. It is a 

 permanent resident from at least Massachusetts south- 

 ward. 



Of our four " horned " Owls, the Long-eared has rela- 

 tively the largest and most conspicuous " ear-tufts," the 

 Short-eared the smallest, while in the Great Horned Owl 

 and Screech Owl the ears are of about the same propor- 

 tionate size. The Great Horned Owl, however, is found 

 only in the wilder, more heavily wooded parts of the coun- 

 try, and is hardly to be included in a list of our common 

 birds. It is the largest of our resident Owls, the males 

 measuring twenty-two inches in length, while its "ear- 

 tufts " are nearly two inches long. 



The Screech Owl is doubtless the commonest of our 

 Owls, as it is also the most familiar, nesting about and 



Screech Owl, even in our houses when some favor- 



Megascops asio. able hole offers. It has little to say for 



Plate xx. itself until its family of four to six 



fuzzy Owlets is safely launched into the world ; then, in 



July or August, we may hear its melancholy voice not 



a "screech," but a tremulous, wailing whistle. It has 



several other notes difficult to describe, and when alarmed 



defiantly snaps its bill. 



Some Screech Owls are gray, others bright reddish 

 brown, and these extremes are connected by specimens 

 intermediate in color. This difference in color is not due 

 to age, sex, or season, and is termed dichromatism, or 

 the presence in the same species of two phases of color. 

 The same phenomenon is shown by other birds, notably 

 certain Herons, and among mammals by the gray squir- 

 rel, some individuals of which are black. The observa- 



