Sapphire-vented Pufflegs are large pufflegs that are mostly green with blue on the front of the crown, purple undertail coverts, characteristically large white leg puffs, and a long, forked bluish-black tail. Sapphire-vented Pufflegs inhabit humid montane areas with open vegetation, including the borders of glades in tall, wet montane forests, or around grassy, páramo slopes. They typically forage at low levels on nectar from small flowers, and frequently perch while doing so. Although Sapphire-vented Puffleg is widely distributed, its biology is not well known. A further mystery regarding this species is that, although it can be common where it occurs, there are several unexplained gaps in its distribution.