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",[10] 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.