Green-tailed Emeralds are endemic to Venezuela and while seasonally common, they tend to have irregular population movements. The male is similar to the Blue-tailed Emerald (Chlorostilbon mellisugus), but has a green tail. Both sexes are very difficult to distinguish from Narrow-tailed Emeralds (Chlorostilbon stenura). Green-tailed Emeralds are most common at lower elevations where they are found along the edge of humid forests, in gardens, or in cultivated areas. At higher elevations, they also frequent the borders of humid woodlands. In both places, they prefer open areas and tend to forage at midlevel. Foraging behavior varies but includes stealing nectar from the territories of other hummingbirds, traplining at flowers with low nectar rewards, and males guarding nectar-rich feeding territories. Individuals are usually seen singly.