The male, measuring 10.5 - 11.5 cm, has a slightly decurved upper bill, the upper mandible is black, the lower mandible red, tipped black.
Upper parts are dark, shining green, with a small white/greyish post occular spot.
The tail is deeply forked, although this character is often hard to detect when the bird is perched and the tail feathers are held together.
The female averages about 1 cm shorter than the male with a longer post ocular spot with a pale breast and tail less sharply forked.
Cuban Emeralds feed on the nectar of flowering shrubs and trees and insects are caught in the air by hawking.
This species readily adapts to habitats disturbed by humans and we saw it daily in and around the resort wherever flowers provided nectar. At first light we could always be sure that one of the first birds to welcome the day would be a Cuban Emerald, often several of them squabbling and jostling for position at the flowers. It was delightful to sit and watch them as we sipped our first coffee of the morning.
As I look outside at a snowy back yard and a temperature around minus 12° the memory seems ever sweeter!