A relatively small, compact vireo. Adult is olive-green on the back and olive-gray on the wings, with a gray crown that contrasts with the back, and dusky lores and eyeline, and a short white supercilium that arches a bit over the eye. Underparts show varying amounts of pale yellow depending on age and feather wear; throat and undertail are more yellow than the remainder of the underparts. Worn adults may be mostly whitish below. Bill generally looks shorter than those of other vireos and the tail is relatively short. Warbling Vireo typically lacks bright yellow tones underneath and has pale lores. However, first fall Warbling can be nearly as yellow below as Philadelphia. Bell's Vireo has at least one obvious wingbar, paler gray lores, and a longer tail that is usually cocked up.

Length: 13 (cm) Wingspan: 20 (cm)

Voice:

Quick, lilting, choppy phrases, with sing-song quality, separated by short pauses, like Red-eyed Vireo but thinner, weaker. Calls include low nasal and scolding notes.

Habitat:

Deciduous and mixed woodlands.

Behavior:

Forages at all levels of canopy, rarely to ground. Nest is a fine cup suspended from forked tree branch. During migration and winter, sometimes joins flocks with other warblers and vireos.

Feeding:

Gleans foliage for a variety of insects and other invertebrates; occasionally eats berries.