Spot-backed antwren

The spot-backed antwren is 11 to 12 cm (4.3 to 4.7 in) long and weighs 9.5 to 10.5 g (0.34 to 0.37 oz). Adult males have a black crown and nape, a long white supercilium, a black streak through the eye, and grayish ear coverts. Their back and rump are dark gray with white edges on most back feathers and blackish patches. They have white-edged black scapulars and a hidden white patch between them. Their flight feathers are gray and black with white edges towards the end; their wing coverts are black with white tips. Their tail is black with white feather tips and white outermost feathers. Their throat and underparts are mostly white with a pale gray tinge on the sides and rear. Adult females have a buff forehead, some buff on their face, white spots on their crown, and a buff breast; they are otherwise like males.