The Black-backed Bush Tanager has a black head, back, wings, and tail, with a broad white throat and white marks on grey underparts. A 1997 survey at Guandera in northeastern Ecuador recorded it in primary forest and páramo.
The adult male described in 1885 had a black head, back, wings and tail, grey underparts marked with white, and a broad white throat. Described females showed olive on the flanks and wing edges, but a male also showed this weakly. Young birds had brownish wing edges and less white on the belly.
Cresswell et al. surveyed about 650 ha of Guandera Biological Reserve from 17 July to 11 September 1997, at 3,000–4,100 m. Table 2 records one observation under primary forest and three under páramo, with none listed under secondary scrub or farmland. The site included high montane Guandera forest around 3,500 m and treeline forest, but the few records do not establish a range-wide habitat preference.
An extinction-risk assessment has not been added yet.