Rio Branco Antbird

The Rio Branco antbird is 14 to 15.5 cm (5.5 to 6.1 in) long; one individual weighed 14.5 g (0.51 oz). Adult males are almost entirely black, with white edges on their outer scapulars, a white patch between them, and a hidden white patch under them. Their wing coverts and tail feathers have white tips and their flight feathers have white inner edges. Females have a brownish gray head and upperparts with a white interscapular patch. Their wings and tail are dark gray with greenish gray edges on the flight feathers. Voice: The male Rio Branco's song is "a couplet consisting of short buzzy note and longer, clearer note, repeated 4–10 (most often 4–7) times". Females often interject a "loud buzzy note" which the male then answers with a similar, but lower-pitched, note. The species' calls include a "duo or trio of abrupt notes, delivered rapidly, and unclear whine that sounds like a tree branch squeaking in wind".