辨識
A slender, long-tailed bird of dense gallery forests and river islands in northern Brazil and extreme southwestern Guyana. Male is mostly black with tail feathers tipped white and with white scalloping on wings. Female is very different: brownish-gray above and buffy below, with a black tail and white throat streaked black. Like other Cercomacra, tends to stay concealed in dense vine tangles in the canopy and midstory, where it clambers slowly about, usually in pairs, searching for insects. Best detected by voice; two-noted song is given in series of 3–5 phrases, with hiccupping effect; similar to song of Gray Antbird but higher-pitched, faster, and less hoarse. Female is unlike any other species in range. Male is darker than Gray and Blackish antbirds, which do not occur in the same habitat and have different voices. Plumage recalls Dot-winged Antwren, but Rio Branco Antbird is considerably larger.