294, WARBLING VIREO. 
equally tireless in the pursuit of his insect prey; both these birds sing as they go, with 
an unconscious air, as if in a reverie; but the easy and wonderfully skilful modulation 
of the former’s flowing song contrasts to great advantage with the Red-eye’s abrupt 
and somewhat jerky notes. Both are among the most persistent of our musicians; in 
the Middle States, for example, their notes are heard from the latter part of April until 
far into September, and at all hours of the day. But much as we may admire Gilvus 
in the agreeable sentiment which his song inspires, we owe him a higher and more 
respectful consideration for the good services he renders us in a very practical way. 
Inhabiting by choice our parks, lawns, and orchards, and even the shade-trees of our 
busiest streets, rather than the untried depths of the forest, these birds collectively 
render efficient service by ridding us of unnumbered insects, whose presence is a pest, 
as well as a continual annoyance to sensitive persons. They take a foremost place 
among the useful birds for whose good services in this regard we have reason to be 
grateful, being much more beneficial than the European Sparrows, which we have 
imported for the same purpose, and against whose insolent aggressions these tender 
birds should be protected. The comparative abundance of these two species being duly 
considered, there can be but one opinion in the matter of their respective efficiency in 
destroying noxious insects; for the Vireos are particularly insectivorous birds, while 
Sparrows eat insects only at certain seasons, and then only through caprice; their 
natural food is seeds, and at present, in this country, they feed for the most part on 
street garbage.” 
The Warbling Vireo is in full song when it arrives from the South, in south- 
western Missouri about April 28, in Wisconsin fully three weeks later. The very 
plain and modest colors account for its being frequently overlooked and confounded 
with other birds. It usually searches in the highest tops of tall shade-trees for insect 
food, especially under the leaves and branches, and always in that near-sighted way, 
peculiar to all Vireos. We can scarcely see it, as it moves along the branchés, but . 
nevertheless we know that it is there, for the familiar, mellow song is incessantly 
uttered. From the tall elms and maples around our dwellings its music resounds from 
early morn till late in the afternoon, and from its arrival until long after the summer has 
gone. The song is not so loud and powerful as that of the Red-eyed Vireo. It is more 
prolonged, more liquid, sweeter, and exceedingly melodious. Once heard, it is ever remem- 
bered. Like its near congener, it also sings during the warmest part of the day, and 
even in July and August, when almost all other birds are silent. 
Like all other Vireos, the Warbling Greenlet builds an elaborately woven and 
beautiful basket-like nest. It is usually suspended at a height from thirty to fifty feet, 
and is built in a horizontal-twig near the top of the tree, “secure from intrusion from 
their human neighbors, and protected by the near presence of man from all their more 
dreaded enemies.” It is almost always protected from rain and sun by a canopy of 
leaves. In the far West, in Utah, Mr. Ridgway found nests, which were built in aspens 
only about four feet from the ground. Other nests, on the contrary, were built fifty to 
seventy and even hundred feet from the ground, “right under the canopy of foliage of 
such large trees as the elms, maples, and poplars, where they may sway in the breeze, 
but are secure against ordinary accidents of the weather, and remote from most enemies, 
