White-winged Black Tyrant

The white-winged black tyrant (Knipolegus aterrimus) is a species of bird in the family Tyrannidae, the tyrant flycatchers. It is found in Argentina, Bolivia, Paraguay, Peru, and as a vagrant to Brazil and Chile. == Taxonomy and systematics == The white-winged black tyrant was formally described in 1853 as Cnipolegus aterrimus. The genus' spelling was later changed to Knipolegus. What is now Knipolegus franciscanus was long treated as a subspecies of K. aterrimus. By 2008 HBW had treated it as a full species. Following a 2012 publication that confirmed its status, other taxonomic systems followed suit, though they variously call it the Sao Francisco black tyrant and caatinga black-tyrant. The white-winged black tyrant's further taxonomy is unsettled. The IOC and the Clements taxonomy assign it three subspecies, the nominate K. a. aterrimus (Kaup, 1853), K. a. anthracinus (Heine, 1860), and K. a. heterogyna (Berlepsch, 1907). BirdLife International's Handbook of the Birds of the World (HBW) recognizes heterogyna as a separate species, the white-rumped black-tyrant. Clements recognizes heterogyna as the "white-winged black-tyrant (white-rumped)" within the species. This article follows the one species, three-subspecies model. == Description == The white-winged black tyrant is 16 to 18 cm (6.3 to 7.1 in) long.…