Male Green-tailed Goldenthroats are entirely green and females are mostly green with green-speckles on their white underparts. Both are smaller than but very similar in appearance to the White-tailed Goldenthroat (Polytmus guainumbi). They inhabit the edges of sandy forests or sandy savannas with scattered bushes. Unlike the White-tailed Goldenthroat, the Green-tailed Goldenthroat doesn’t seem to prefer areas in close proximity to water. This species gathers nectar from scattered plants, especially those in the Melostomataceae genus. They also forage for insects by hawking or gleaning.