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, 
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 : — 
fa 
Fig. 65.— Yellow Warbler, two- 
thirds natural size. 
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 caterpillars 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 
