Rusty-backed antwren

The rusty-backed antwren (Formicivora rufa) is a species of bird in the family Thamnophilidae, the "typical antbirds". It is found in Bolivia, Brazil, Paraguay, Peru, and Suriname.

The rusty-backed antwren is 12 to 13 cm (4.7 to 5.1 in) long and weighs 11.5 to 14 g (0.41 to 0.49 oz). The males of all three subspecies have a tawny rufous crown and upperparts. They have a white supercilium and the rest of the face and the throat are black. The middle of the breast is black with a white edge separating it from the cinnamon-buff flanks; the belly is white. The folded wings show lines of white dots. The tail feathers are black with chestnut fringes, white sides, and white tips. The nominate female has paler rufous upperparts than the male. The face, throat, and chest are streaked black and white and the rest of the underparts are cinnamon. The female of F. r. urubambae has much heavier streaking on the underparts than the nominate and its tail is blacker. The female of F. r. chapmani is intermediate between the other two subspecies but closer in appearance to urubambae.