White-tailed Emerald

The white-tailed emerald (Microchera chionura) is a species of hummingbird in the "emeralds", tribe Trochilini of subfamily Trochilinae. It is native to the Talamancan montane forests. == Taxonomy and systematics == The white-tailed emerald was formerly placed with the coppery-headed emerald in the genus Elvira. A molecular phylogenetic study published in 2014 found that these two species were closely related to the snowcap in the then-monospecific genus Microchera. The International Ornithological Committee and the Clements taxonomy placed the three species together in Microchera which has priority. However, BirdLife International's Handbook of the Birds of the World retains them in Elvira. The white-tailed emerald is monotypic. == Description == The white-tailed emerald is 7.5 to 8 cm (3.0 to 3.1 in) long. Males weigh about 3.3 g (0.12 oz) and females 3.1 g (0.11 oz). Both sexes have an almost straight black bill whose mandible has a pinkish base. The adult male has bronzy green upperparts that becomes dark copper-bronze on the uppertail coverts. Its central two pairs of tail feathers are copper-bronze and the other three pairs white with black tips. It has a glittering green throat and chest and white belly, vent, and undertail coverts. The adult female also…