WARBLING VIREO. 131 
XXXVIT. 
WARBLING VIREO. 
Tue warbling is the smallest of the three vireos. 
Its back is grayish olive, and its breast is tinged 
with yellow. It may be distinguished from the 
others by his song. 
Dr. Brewer says: “This vireo... is to a 
large extent a resident of villages, towns, and 
even cities. It is by far the sweetest singer that 
ventures within their crowded streets and public 
squares, . . . and the melody of its song is ex- 
quisitely soft and beautiful. It is chiefly to be 
found among the tall trees, in the vicinity of dwell- 
ings, where it seems to delight to stay, and from 
their highest tops to suspend its pensile nest. It 
is especially abundant among the elms on Boston 
Common.” 
By reason of their dainty coats and shapely forms, 
their pretty ways and their repose of manner, the 
vireos remind one most forcibly of the waxwings. 
Birds naturally group themselves by occupation, 
and, as a Darwinian corollary, by coloring. The 
sparrows spend most of their time on the ground 
searching for seeds, and are protected by their 
earth-colored suits; the woodpeckers live clinging 
to tree trunks, and many of them are disguised by 
their likeness to the bark; the flycatchers take 
their living from the insects that swarm in the 
