The Coppery-headed Emerald Hummingbird (Elvira cupreiceps) is endemic to Costa Rica, & is tiny: 3 in (7.6 cm) in length, and weighs only 3 g (0.11 oz). The male has distinctive coppery crown and rump with a whole green belly and white vent. The female has a white belly and a narrow black subterminal band on white outer rectrices of the tail. Its noticeably decurved bill sets it apart from similar the allopatric White-tailed Emerald. Males form small leks at middle levels of forest edges.