13 cm (5") Fairly common. Western North America. Dense undergrowth. Nests on ground.
Male has a black hood, female's is gray. Unstreaked yellow underparts including undertail coverts. Best told from similar Mourning and Connecticut Warblers by its incomplete eye ring (bold white crest above and below eye).
Song: buzzy trill with an ending downslur "sweeter-sweeter-sweeter, sugar-sugar".