A medium-sized (5 inches) vireo, the Warbling Vireo is most easily identified by its plain brown-gray upperparts and wings, pale breast, and faint white eye-stripes. This species may be separated from the Red-eyed Vireo (Vireo olivaceus), which also has a pale breast and plain back, by that species’ brighter eye-stripes. Male and female Warbling Vireos are similar to one another in all seasons. The Warbling Vireo breeds across the northern United States and southern Canada. In the west, this species’ range extends southward at higher elevations as far as central Mexico. Warbling Vireos breeding in the U.S. and Canada spend the winter from central Mexico south to northern Central America, while populations breeding in central Mexico migrate short distances, if at all. Warbling Vireos breed in a variety of deciduous or mixed deciduous and evergreen woodland habitats. During the winter, this species may be found in a variety of semi-open habitats around tropical forests. Warbling Vireos primarily eat small insects, but also eat small quantities of fruits and berries during the winter. In appropriate habitat, Warbling Vireos may be seen foraging for food on leaves and branches in the tree canopy. Birdwatchers may also listen for this species’ song, a series of fluty notes more reminiscent of a warbler than a vireo. Warbling Vireos are primarily active during the day, but, like many migratory songbirds, this species migrates at night.
Uncommon summer residents from late April to late September, breeding from mid-May to mid-July. Nests in open shade trees in residential areas. Sexes are similar.