Acre Antshrike

The Acre antshrike is about 16 cm (6.3 in) long and weighs about 22 g (0.78 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 have a glossy black crown and nape with a few white feathers on the forehead and nape; the rest of their head and neck are a less glossy black. Their back is mostly bluish black with dark bluish gray rump and uppertail coverts. Their wings, scapulars, and wing coverts are mostly black and their primaries blackish. Voice: The Acre antshrike's song is "an accelerating, descending series of rich notes with a distinctive, higher pitched, bisyllabic terminal bark: kuk kuk-kuk-kuk-ku-ku-ku-ku'wah'AH". Its calls include a "cawed aw and a longer, descending awwr". Whitney et al. noted specific differences between this species' song and those of other Thanomphilus antshrikes.