Northern Slaty Antshrike

The northern slaty antshrike is 13 to 15 cm (5.1 to 5.9 in) long and weighs 16 to 18 g (0.56 to 0.63 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. p. punctatus have a gray forehead and a black crown. Their back is gray with a few black feather tips and a hidden white patch between their scapulars. Their face is gray. Their wings and wing coverts are black with white spots and edges. Voice: The northern slaty antshrike's song is "an accelerating series of usually 10–15 progressively shorter notes starting with laboured, slow-paced notes that are countable, ending with trill of abrupt uncountable notes often sounding higher in pitch". Its pace varies among the subspecies; that of T. p. leucogaster is the fastest.