Large-billed Antwren

The large-billed antwren is 12 to 13 cm (4.7 to 5.1 in) long and weighs 12 to 14 g (0.42 to 0.49 oz). As its English name and specific epithet imply, its bill is heavier than those of most other Herpsilochmus antwrens. Adult males have a black crown and nape, a long whitish supercilium, a narrow black streak through the eye, and grayish ear coverts. Their back and rump are gray with a black and white patch between the scapulars and white-tipped black uppertail coverts. Their wings are black with white-tipped coverts and flight feathers with white edges towards the end. Voice: The large-billed antwren's song is a "high, fast, chattering series, rising at start, descending and decelerating at end". Typically the male sings and the female quickly answers. Its calls include a "a rapidly delivered triplet in which notes become shorter and drop in pitch" and an "abrupt downslurred note" like that of several other members of its genus.