Uncommon but widespread in fields with hedges and brushy cover. Unlike any other warbler, a skulky bruiser. In spring, often sits out and slowly sputters its song of repeated notes. Frequently contorts body, sometimes leaning forward as if to scold you. In courtship flight, will fly into the air with exaggerated wingbeats, chest pumped out, before returning to base. Most of the time it skulks at head height in cover. Often sits quietly or moves slowly to avoid drawing attention; always a loner. Song is a repeated series of varying harsh notes, interspersed with chucks and squeaks. ID: Massive — is it really a warbler! Thick bill and long tail. Brilliant yellow chest, white spectacles, and dark lores really catch the eye. All plumages similar with females averaging duller and paler-lored. 1st-yr often has paler bill. W. populations average larger white malars and less olive upperparts.