BIRDS OF MINNESOTA. 365 
VIREO GILVUS (VieILLotr). (627.) 
WARBLING VIREO. 
Excepting the Red-eyed, this is the most abundantly repre- 
sented species of the genus. It arrives about the 10th of May, 
remaining until late in September, and occasionally October. 
Its habits in common with the others of its genus, are such 
that its presence might escape the attention of the casual ob- 
server but for its beautiful warblings which there is no mistak- 
ing forany other. It is emphatically the domestic representa- 
tive of the vireos, notably preferring the poplars in which to 
build its nest, and rear its young. Rather than occupy the 
other common trees in the vicinity of dwellings, it will go to 
the small groves and borders of the forest, but is almost never 
found in the denser timber. It is not a whit behind the Red- 
eyed Vireo as an insecticide, leaving nothing of the kind living 
on the trees it specially inhabits and few anywhere very 
near. 
Its song is liquid, fluent, exhilarating, undulating, smooth 
and melodious as a flute, and remarkably prolonged for a bird 
of its size and genus. The nearest approximation to any de- 
scription which I can conceive of is a fairly strong, sweet trill, 
modulated into symmetrical undulations, with just interruptions 
enough to keep the vocal cords always up to their best. It 
sings while skipping from twig to twig amongst the topmost 
branches of the tree in which its form remains essentially in- 
visible while searching for its special food. The nest is sus- 
pended in a very delicate manner from small horizontal twigs 
where they unite with a larger perpendicular one, around which 
fibres of bark are wound with much skill to amply secure it. 
It consists of fine strips of bark and fibres of wood, dried grass, 
vegetable down, shreds of larval cocoons and fragments of 
wasp’s nests, and is lined with fine bark. It is usually about 
two inches in depth, but occasionally much more shallow. The 
characteristics of the vireos are in nothing more marked than 
in the slim, white eggs sparingly spotted with reddish-black 
at the larger end. They are generally limited to five in num- 
ber, and are laid about the first week in June. The nest is 
placed usually well toward the top of the tree, however tall it 
may be. 
SPECIFIC CHARACTERS. 
Third, fourth and fifth quills nearly equal; second and sixth 
usually about equal, and about .25 of an inch shorter than the 
third; exposed portion of the spurious quill about one-fourth 
