Description wikipedia

The blue-billed black tyrant (Knipolegus cyanirostris) is a species of bird in the family Tyrannidae, the tyrant flycatchers. It is found in Argentina, Brazil, Paraguay, and Uruguay. The blue-billed black tyrant is 14.5 to 15 cm (5.7 to 5.9 in) long. Adult males are almost entirely glossy black but for faint white edges on the underside of their remiges. Adult females have mostly rufous-brown upperparts. Their crown is a brighter rufous, their rump rufous, and their tail coverts bright cinnamon. Their wings are blackish with buff to cinnamon edges on the coverts that show as two wing bars. Their tail is dusky with rufous edges to the feathers. Their underparts are mostly whitish to yellowish white with heavy blackish brown streaks and their crissum is cinnamon-rufous. Males have a bright red iris, a pale blue bill with a black tip, and black legs and feet. Females have a pale red to orange iris, a blackish bill with usually a bluish mandible, and black legs and feet. The blue-billed black tyrant is found from Mato Grosso do Sul, Minas Gerais, and Espírito Santo in southern Brazil south through Uruguay and eastern Paraguay into Argentina to northern Buenos Aires Province. It primarily inhabits the edges of humid forest and gallery forest and shuns their interiors. Less often it also occurs into semi-open scrublands near forest. In elevation it ranges from sea level to 2,200 m (7,200 ft).