Calliope HummingbirdStellula calliope
2 3/4-3 1/4" (7-8 cm). The smallest North American hummingbird. Male metallic green above; has white gorget with purple-violet rays, which can be raised to give a whiskered effect. (All other North American hummers have solid-colored gorgets.) Female green above, white below, with dark streaks on throat, buffy flanks, and white-tipped tail corners. Resembles the female Rufous Hummingbird, but smaller, with smaller bill, paler flanks, and less rufous at base of tail.