Cassin's Vireo
Vireo cassinii
The vireo is 11–14 cm (4–6 inches) long. It has a grayish olive head, back, and flanks, with whitish underparts. One of its distinctive features is the solid white "spectacles" around its eyes, along with white wing bars. These markings set it apart from other similar species like the plumbeous vireo and the blue-headed vireo.
ID text from Wikipedia, CC BY-SA 4.0
Philadelphia Vireo
Vireo philadelphicus
Adults are mainly olive-brown on the upperparts with yellow underparts; they have dark eyes and a grey crown. They have no wing bars and no eye ring. There is a dark line through the eyes and a white stripe just over them. They have thick blue-grey legs and a stout bill. The Philadelphia vireo is similar in appearance to the warbling vireo, but can be reliably distinguished by having much yellower underparts, and dark lores.
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
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