SONG BIRDS OF ORCHARD AND WOODLAND. 195 



crown, wings, and tail, for the Yellow Warbler has no black 

 markings. 



Although the Yellow Warbler is not now commonly found 

 in the woods, it is sometimes seen within their borders, and 

 is common in thickets along streams and roads, as well as in 

 bushy pastures. It is not usually 

 seen on the ground or in the tops 

 of the tallest trees, but visits all 

 parts of trees and shrubbery. 



Its alarm note is a loud chirp. 

 Its usual song has much the quality 

 of a whistle, and may be expressed 

 by the syllables we'-chee, we'-chee, Figr ' 65.-Yeiiow warbier.two- 



J J thirds natural size. 



wee'oo. The song is frequently 



much longer, has several variations, and often closely re- 

 sembles one song of the Chestnut-sided Warbler. 



The nest building of this bird is performed entirely by the 

 female ; the nest is daintily but loosely constructed, and is 

 very rapidly built. The following brief account of the nest 

 building, taken from Mr. Mosher's notes, May 16, 1899, 

 shows this bird to be an enemy of the cankerworm and the 

 tent caterpillar : 



She first laid a foundation of a few straws and placed upon them 

 the cotton or down from fern fronds. These she bound together with 

 the silk from a tent caterpillar's web. Then she went alternately 

 for the cotton and the silk, stopping occasionally at an apple tree and 

 feeding for a moment or two on cankerworms. When I went past the 

 nest at night I found she had it nearly complete ; the lining only was 

 lacking. 



It would be hard to find a summer bird more useful among 

 the shade trees or in the orchard and small-fruit garden than 

 this species. Almost entirely insectivorous, it feeds on many 

 of the greatest pests that attack our fruit trees, vines, and 

 berry bushes. Whenever the caterpillars of which it is fond 

 are plentiful, they form about two-thirds of its food. It is 

 destructive to the small caterpillars of the gipsy moth and 

 the brown-tail moth, and is inordinately fond of cankerworms 

 and other measuring worms. Tent caterpillars are com- 

 monly eaten. Small bark beetles and boring beetles are 



