Bolivian Slaty-Antshrike

The Bolivian slaty antshrike is about 14 cm (5.5 in) long and weighs 18 to 20 g (0.63 to 0.71 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 gray forehead and a black crown. Their back is gray with a few black spots and a hidden white patch between their scapulars. Their face is gray. Their wings, scapulars, and wing coverts are black with white spots and edges. Their tail is black with white tips and spots on the feathers. Their underparts are light gray with much white on the belly. Adult females have a bright reddish-brown crown and yellowish olive-brown upperparts. Their wings are dark brown with white spots and edges on the scapulars and pale buff edges on the flight feathers. Their tail is dark brown with white tips and spots on the feathers. Their underparts are white in the center and light yellowish brown across the breast and on the sides, flanks, and crissum.

The Bolivian slaty antshrike is found in the central Bolivian departments of Beni, Cochabamba, and Santa Cruz, in adjoining extreme western parts of the Brazilian the states of Mato Grosso and Mato Grosso do Sul, and in far northern Paraguay's Alto Paraguay department. It inhabits the understorey to mid-storey of dry semi-deciduous forest, gallery forest, larger areas of more humid forest, and secondary forest. In elevation it reaches 600 m (2,000 ft) in Brazil and 950 m (3,100 ft) in Bolivia.

The diet of the Bolivian slaty antshrike has not been detailed but is assumed to be arthropods. It usually forages singly or in pairs. It usually forages in the understorey to mid-storey, mostly between 1 and 7 m (3 and 23 ft) of the ground. It hops through vegetation, gleaning prey while reaching from a perch; it also makes short upward sallies. It takes prey from leaves, branches, and vines. It is not known to join mixed-species feeding flocks or follow army ant swarms.