Large, conspicuous hummingbird of tepui highlands. Green above and rufous below. Note extensively rufous outer tail feathers, which are easily seen as birds tend to flare tail frequently. Generally common at higher elevations (above 1000 m), especially at forest edge and in lower-stature, scrubby vegetation. Feeds on nectar and pugnaciously defends patches of flowers against other hummingbirds. Not shy and will approach to investigate observers. In territorial interactions, gives a rich, sharp note, often doubled, repeated incessantly, and similar to calls of more widespread Gray-breasted Sabrewing; also gives a single, ascending, burry note, possibly as an alarm call. No other hummingbird in highland range is as large or shows as much rufous.