BIRDS OF PENNSYLVANIA. 
263 
The Red-eyed, Philadelphia and Warbling Vireos (subgenus Vireosylva Bonap.) 
have no wing bands, but the White-eyed, Yellow-throated and Blue-headed species 
(subgenus Lanivireo Bd.) have two distinct wing bands formed by white tips of 
middle and greater coverts. The feathers of upper parts are greenish-olive of differ¬ 
ent shades ; the top of head in some is similar to the back, but in others the top of 
head is more or less plumbeous. The lower parts are whitish or yellowish or both ; 
eyes brown, except in the Red and White-eyed species, and even the young of these 
have brownish irides. The legs and feet are generally dark lead color, and the bills 
are similar but paler below. The sexes are alike, and the young are not very ma¬ 
terially different; size small, the white-eyed (smallest) is about 4| inches long and 
the Red-eyed (largest) is about inches in length. The short, straight, stout and com¬ 
pressed bill has a slightly curved culmen, and it is notched and rather abruptly 
hooked at tip. AVings pointed or rounded (very slightly) and equal to or longer than 
the even tail. Primaries 10; the first much the smallest; third or fourth quills longest. 
Four toes, three in front and one behind ; claws much curved and sharp; short basal 
joint of middle toe wholly adherent to both outer and inner toes; tarsus rather slen¬ 
der and longer than middle toe with claw. “ Next after the Warblers, the Greenlets 
are the most delightful of our forest birds, though their charms address the ear and 
not the eye. Clad in simple tints that harmonize with the verdure, these gentle 
songsters warble their lays unseen, while the foliage itself seems stirred to music. 
In the quaint and curious ditty of the White-eye—in the earnest, voluble strains of 
the Red-eye—in the tender secret that the Warbling Yireo confides in whispers to 
the passing breeze—he is insensible who does not hear the echo of thoughts he never 
clothes in words.”— Coues. 
Genus VIREO Vieillot. 
Vireo olivaceus (Linn.). 
Red-eyed Vireo. 
Description ( Plate 40 ). 
Largest of the genus. Length about ; extent about 10^ inches; bill blackish 
above, below bluish-white; feet and legs lead color; iris red ; back, rump, upper 
parts of wing and tail feathers olive-green ; sides of head and neck paler ; crown 
dark-ash, edged with a blackish line; a well-defined whitish line from nostril over 
the eye and back of it; a dusky stripe through the eye ; under parts white, shaded 
on the sides and tail-coverts with greenish-yellow, brightest on the under wing- 
coverts and crissum. Tail and wing feathers blackish, edged on the outside with 
greenish-yellow, with whitish on inside. 
Young. —Irides plain brown or reddish-brown ; ash of crown less distinct; grayish- 
yellow rather than greenish above, but the sides, under wing and tail-coverts are 
quite brightly colored. 
Habitat.— Eastern North America, to the Rocky mountains, north to the Arctic 
regions. 
The Red-eyed Yireo is a common summer resident from late in April 
to the last of September. In this state it is much more abundant than 
any other of the Vireos. In summer the voice of this agile, fluent and 
tireless songster is heard on almost every hand in forests and groves. 
This bird is a most devoted foster-parent, feeding and guarding the 
clamorous young Cow-bird with the same care and solicitude that it be¬ 
stows upon its own offspring. Indeed, sometimes it seems that they 
are even more attentive to the noisy, red-mouthed Cow-birds than they 
are to their own young. The Red-eyed Yireo, like others of the family, 
