This species has greatly expanded its range in the past century. It frequently hybridizes with Golden-winged Warbler, often replacing Golden-wings where their ranges come into contact. Male: The back and nape are a dingy olive-yellow. The crown, face, and underparts are bright yellow, except for the white undertail coverts. A black line runs from the lores through the eye. The tail and wings are blue-gray, with two bold white wing bars and extensive white on the outer tail feathers. Female: Similar to male, but the olive-yellow of the back and nape extends over the crown. The eye line is not as dark, and the wing bars are narrower than on the male. Juveniles resemble adult females.

Length: 11 (cm) Wingspan: 17 (cm)

Voice:

Song is a high thin note, followed by a low buzz: beee-BZZZZZZZZZZ.

Habitat:

Brushy fields, early successional forest, forest edge.

Behavior:

Nests on or near the ground.

Feeding:

Gleans insects from foliage, usually on the upper and outer branches of shrubs. Feeding is slow and deliberate, similar to a vireo. May hang upside down like a chickadee.