Despite its geographical moniker, this distinctly uncommon bird is not confined to the state of Rio de Janeiro; indeed, it is now rather hard to find there. Considered Near Threatened by BirdLife International, this antbird is endemic to the Brazilian Atlantic Forest, where it is distributed, very locally, from around central Bahia south to Rio de Janeiro. Doubtlessly in decline, it is fortunate for this species’ survival prospects that the birds are not dependent on primary habitats but, like many of their congeners, are found in dense undergrowth, sometimes just small patches, especially in bamboo or vine tangles, both within forest and in more secondary situations. Its altitudinal range reaches to approximately 950 m. The sexes differ in plumage, much like the closely related but wholly allopatric Dusky Antbird (Cercomacra tyrannina), with the male predominantly gray-colored and the female clad in brown and tawny. Both sexes sing, but it is usually the male that approaches, alone, in response to playback of its quiet, repetitively but slowly given ‘cranking’ song. The Rio de Janeiro Antbird is a poorly known bird, made more difficult to study through a combination of its rarity and skulking habits.