White-shouldered Antshrike

The white-shouldered antshrike is 15 to 17 cm (5.9 to 6.7 in) long and weighs 23 to 30 g (0.81 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 significant sexual dimorphism. Adult males of the nominate subspecies T. a. aethiops are mostly black. They have a few white spots on their wing's lesser coverts and the bend of the wing, white underwing coverts, and a blackish gray lower belly and crissum. Adult females are entirely deep reddish brown. Voice: The male white-shouldered antshrike's song is "a short and slowly paced...series of low-pitched, complaining notes delivered at steady pace and even pitch and intensity"; female song is similar but higher-pitched. It has been written as "anh...anh...anh...anh...anh" given at about one note per second.