White-sided hillstar Oreotrochilus leucopleurus

Small hummingbird of the Andes from southern Bolivia through Argentina into central Chile; found in rocky and shrubby valleys, villages, and any open or semiopen areas with flowers. Often builds nest under eaves of buildings or bridges: a bulky cup of plant material and wool to insulate against cold nights. Fairly common. Readily identified in most of range by extensively white tail. Male has an emerald green gorget and a broad blue-black stripe on belly. Female is rather drab, but note slightly decurved bill, spotted throat, and tail pattern.