A typical forktail, with piebald plumage and long tail. Like most other forktails, it inhabits shaded whitewater streams, along which it perches on boulders and low-hanging branches. Unmarked black back distinguishes it from Slaty-backed and Spotted forktails. Can be confused with Black-backed Forktail, but unlike that species, white does not extend behind the eye. Often detected by its vocalizations, a harsh buzzing whistle and high metallic whistles.