Black-chested Mountain-Tanager (Cnemathraupis eximia) is rather uncommon and local, and one of two members of the genus Cnemathraupis, the other being Golden-backed Mountain Tanager (Cnemathraupis aureodorsalis). Molecular phylogenetic analyses rejected a monophyletic Buthraupis, to which both of these species belonged, and Cnemathraupis was erected for these two species (Burns et al. 2014, Clements et al. 2013). Black-chested Mountain-Tanager ranges in the Andes from southwestern Venezuela south through Colombia and Ecuador to extreme northern Peru. It inhabits high elevation treeline cloud forest, mostly on the eastern slope of the Andes. It overlaps in range with both Hooded Mountain-Tanager (Buthraupis montana) and Masked Mountain-Tanager (Buthraupis wetmorei), but is distinguished from both by having a rich moss green back that contrasts with bright yellow underparts, a black throat and upper breast, and a deep blue crown. Birds in Venezuela differ by having a blue rump. It typically is seen in pairs or small flocks, and sometimes loosely associates with mixed-species flocks. It forages very quietly, unlike the noisy Hooded Mountain-Tanager. It is generally found at higher elevations than Hooded, but can be found with Masked Mountain-Tanagers, sometimes foraging in the same flock. As with Masked Mountain-Tanagers, it is probably more common than the limited number of known localities where it occurs suggests, given such restricted access to proper habitat throughout Colombia and Ecuador. It mainly forages on small fruits and berries. The song is rarely heard, but consists of a long elaborate series of jumbled notes and whistles. Call notes are very weak and unassuming. The genus name Cnemathraupis derives from Greek words kneme-, meaning shin or leg; and thraupis meaning unknown small bird; in ornithology thraupis signifies tanager. The specific epithet eximia is derived from Latin and signifies distinguished (Jobling 2010). In Spanish the common name is Tangara Dorsiverde (Hilty 2011, de Juana et al. 2012).