Although restricted to the tepuis (isolated table mountains) of eastern Venezuela and adjaceng Guyana and Brazil, Rufous-breasted Sabrewings are common. They inhabit the edge of sloping wet forest and favor disturbed areas in particular. Individuals frequently visit low flowers alongside the road, but they also forage in the canopy. In the canopy, they are territorial around most other hummingbirds in the area (including others of its own species). Individuals often frequent the same food patches over and over again until the source is depleted. Males and females are similar in appearance with extensive rufous below and on the outer three tail feathers, giving the tail a rufous appearance when viewed from below.