Cassin's vireo (Vireo cassinii)

Cassin's vireo is a small North American songbird, ranging from southern British Columbia in Canada through the western coastal states of the United States. This bird migrates, spending the winter from southern Arizona to southern Mexico.

The vireo is 11–14 cm in length, with a gray head, back, and flanks, and whitish underparts. It has solid white "spectacles" and white wing bars.

The song, given persistently, consists of short, rough whistled phrases of several notes,.. more