Black-crowned Antshrike

The black-crowned antshrike is 14 to 15 cm (5.5 to 5.9 in) long and weighs 20 to 28.5 g (0.71 to 1.0 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 significant sexual dimorphism. Adult males of the nominate subspecies have slaty gray upperparts with a gray forehead, a black crown and nape, a hidden white patch between their scapulars, and white-tipped black uppertail coverts. Their face is grizzled gray. Voice: The black-crowned antshrike's most common song is "a series of uh notes ending with a single erk at a higher pitch". Both sexes sing, commonly in the morning but at any time of day. The song has been written as "wur wur wur-wur-wur-wur'wur'wur'wur; AH" and "anhanhanhanhanhanhanhanhanhánh". Its calls include "a 1–4-note (usually 2) caw arr-arr and a bark-rattle: arr-grr'r'r'r".