The White-line Tanager has strong dimorphism, with the male being black with a small white line on the shoulder, and the female being entirely rufous. They normally forage in pairs, which helps in identifying them. Males can look very much like Passerini’s Tanagers when the rump is not visible, but the bill is gray instead of blueish. The female is also similar to the Passerini’s, however it has no marks and a black bill. They also approach fruit feeders but are more wary than Passerini’s, preferring to forage in the dense vegetation.