These slow flying hummingbirds inhabit humid lowland forests and gather in the canopy with other hummingbirds to forage. There they sometimes steal nectar from the feeding territories of larger hummingbirds. During courtship displays, males impress females by fanning out their long tails as they zoom from side to side. This behavior is accompanied by a loud cracking sound given by the male. Although the male might be confused with a Wire-crested Thorntail (Discosura popelairii), the Black-bellied male lacks a crest and has a narrow rufous band separating the green gorget and black chest.