The black phoebe flycatcher (Sayornis nigricans) is named from the Latinised form of the Greek name Phoibe, which meant "bright, pure" from Greek phoibos. The phoebe can be recognised by a characteristic "tail-wagging" motion, in which the tail is lowered and fanned. The species name, nigricans, is Latin for "blackish", and was given by William John Swainson in 1827. The flycatchers are the largest family of birds on earth, with over 400 known species. It is usually found near water; marshy ponds, open woodlands along streams, near farm ponds and irrigation ditches, where it feeds on small fish, insects and berries.