Streak-backed Antshrike

The streak-backed antshrike is 16 to 17 cm (6.3 to 6.7 in) long and weighs 22 to 30 g (0.78 to 1.1 oz). Members of genus Thamnophilus are largish members of the antbird family; all have stout bills with a hook like those of true shrikes. This species exhibits slight sexual dimorphism. Adult males of the nominate subspecies have a black crown and nape with a few white feathers on them. Their upperparts are black with a white patch between the scapulars that shows as spots or streaks. Their wings, scapulars, and wing coverts are black with white spots and edges. Voice: Males of the streak-backed antshrike sing "a slowly accelerating, very nasal cunk, cuk cuk-cu-cu-cu-cu-cu-cu 'cu'cu'cucurank"; females sing similarly but at a higher pitch. The species' calls include a variable-length "somewhat downslurred raspy growl" and a "soft squeak or ' peep' ".