Purple-backed Thornbill Ramphomicron microrhynchum

Small hummingbird with an extremely short, straight bill. Males are unmistakable: brilliant purple above and green below. Females are green above and whitish below with dense green spotting, especially on the flanks. Both sexes have a fairly long, notched tail. Occurs in the Andes from western Venezuela to Peru. Usually seen singly in the canopy or borders of humid elfin forest near treeline, though can gather in larger numbers at flowering trees. Also ventures into páramo; occasionally descends to lower elevations in the dry season. Seasonal movements are not understood.