ハシボソアリサザイ Formicivora iheringi

Long-tailed antwren with white flanks, unmistakable within its restricted range. Males are dark gray with a black bib. Females are olive-brown above and cinnamon below with two buff wing bars. Found in deciduous forests, where it forages from the understory to middle levels, usually alone but sometimes loosely accompanying mixed-species flocks. Songs a long series of clear “tiuw” notes.