The black phoebe (Sayornis nigricans) is a passerine bird in the tyrant-flycatcher family. It breeds from southwest Oregon and California south through Central and South America. It occurs year-round throughout most of its range and migrates less than the other birds in its genus, though its northern populations are partially migratory. Six subspecies are commonly recognized, although two are occasionally combined as a separate species, the white-winged phoebe. The black phoebe has predominantly black plumage, with a white belly and under tail coverts. The sexes are identical in color, and juveniles have brown feather tips and brown wing-bars. Its song is a repeated tee-hee, tee ho. It lives in a variety of habitats but is always near water. It is mainly insectivorous and waits on a perch before flying out and catching its prey in the air. It makes an open cup nest which is placed under a cliff or a bridge and cemented in its place with mud.The black phoebe is a medium-sized flycatcher, being 16 cm (6.3 in) in length and weighing 15 to 22 g (0.5 to 0.8 oz). It has predominantly black plumage, with white on its belly and under tail coverts. The white forms an inverted "V" in the lower breast. The sexes are identical and plumage does not vary seasonally. Juveniles have browner plumage, cinnamon-brown feather tips on their body, and brown wing-bars. The bird has brown irises and black legs, feet, and beak. The phoebe can be recognized by a characteristic "tail-wagging" motion, in which the tail is lowered and fanned[clarification needed]. It accomplishes almost all locomotion by flight, which is direct, with steady wing beats. Its song consists of two alternating phrases (tee-hee, tee-ho or sisee, sitsew). The song can be heard from both sexes, but is more commonly sung by males.The phoebes are a genus, Sayornis, of birds in the tyrant flycatcher family. The flycatchers are the largest family of birds on earth, with over 400 known species.The genus name was given by George Robert Gray of the British Museum, and is named after Thomas Say, an American naturalist. The species name, nigricans, is Latin for "blackish", and was given by William John Swainson in 1827. The black phoebe has six subspecies, but these can be divided into two groups which are sometimes considered to be separate species: the nigricans group (black phoebe) and the latirostris group (white-winged phoebe). The first group contains four subspecies, the second group two.