5.0″ long. The adult male Common Yellowthroat has a bright yellow throat and breast, a white belly, and a black mask bordered above by gray or white. The back and wings are olive-brown. The undertail coverts are yellow. There are no tail spots. The female is considerably duller and lacks the black mask but has a faint whitish eye ring that may be broken. The female’s throat usually shows a hint of yellow. First fall males show a trace of a black mask. Immature female birds can be very dull with little or no yellow on the throat. They will still have yellow undertail coverts and a strong contrast between the brown cheeks and whitish throat. The female Common Yellow throat has a whiter belly than the similar immature Mourning Warbler. It also lacks the gray hood or olive breast band of the Mourning Warbler.