Small hummingbird of the high Andes; found in rocky and shrubby valleys, villages, and any open and semiopen areas with flowers. Often builds nest under eaves of buildings or bridges: a bulky cup of plant material and alpaca wool to insulate against cold nights. Fairly common. Readily identified in most of range by its extensively white tail. Male has an emerald green gorget and a rusty stripe on belly (black in northern Peru). Female is rather drab, but note slightly decurved bill, spotted throat, and tail pattern.