Small hummingbird with a very long tail. Bright green overall with a very short, straight bill. The male’s long tail is striking. Sexes similar but females are more spotted below and have a shorter tail. Compare with very similar Black-tailed Trainbearer; Green-tailed has a shorter, straighter bill, a shorter, straighter tail, and is brighter emerald-green. Occurs from Colombia to Peru, from around 1,900 to 3,000 m. Typically found at the edge of forests or shrubby woodlands, but also in drier and more open areas. Occasionally visits feeders, but more often seen feeding at flowering shrubs.