Fairly common by flowing water with nearby rocks or surrogate rocky habitat, from mountain streams to weirs in suburban parkland. Walks quietly along shorelines or in nearby open areas, pumping its very long, white-sided tail up and down. All plumages have gray head and back, with whitish eyebrow, bright yellow belly and vent. Breeding male has black throat, mostly yellow underparts. Breeding female often has some dark on throat, paler yellow underparts. Song is a repetitive series of high-pitched notes; calls include short, high “pseet” and buzzier flight calls.