Amongst the genus Anisognathus, Scarlet-bellied Mountain-Tanager is one of the most wide-ranging and abundant species. It occurs in the Andes from western Venezuela to central Bolivia, and four subspecies are recognized across this wide distribution. Scarlet-bellied Mountain-Tanager is surely an unmistakable bird within its high-Andean forest haunts, being largely black, with a bright blue rump and wing-coverts, and a red patch on the ear-coverts and belly and lower breast. The different subspecies generally vary in the depth of the red color and the color of the undertail-coverts. This species regularly joins mixed-species foraging flocks, like most mountain-tanagers, but is equally frequently observed in single-species groups. The genus name Anisognathus comes from the Greek roots anisos, meaning unequal, and gnathos, meaning lower jaw. The species name igniventris arrives from the Latin roots ignis meaning fire, and ventris, meaning belly (Jobling 2010).