The Warbling Vireo 
75 
to hunt, even among the trees of so busy a 
thoroughfare as Boston Common, an almost 
continuous warble in the early summer in- 
dicates that some unseen singer is hidden there ; 
but even if you get a glimpse of the warbling 
vireo you could not tell him from his red-eyed 
cousin at that height. Modestly dressed, with- 
out even a white eye-brow or wing-bars to re- 
lieve his plain dusty olive and whitish clothes, 
he is the least impressive member of his retiring, 
inconspicuous family. He asks you no ques- 
tions in jerky, colloquial triplets of song, so 
you may know by his voice at least that he is 
not the red-eyed vireo. Some self-conscious 
birds, like the song sparrow, mount to a con- 
spicuous perch before they begin to sing, as if 
they had to deliver a distinct number on a 
programme before a waiting audience. Not 
so with this industrious little gleaner to whom 
singing and dining seem to be a part of the 
same performance — one and inseparable. He 
sings as he goes, snatching a bit of insect food 
between warbles. 
Although towns do not affright him, he really 
prefers wooded border-land and clearings, es- 
pecially where birch trees abound, when it is 
time to rear a family. 
