Spot-billed ground tyrant
The spot-billed ground tyrant is a species of bird in the family Tyrannidae, the tyrant flycatchers. It is found in Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru and as a vagrant in Brazil.
Taxonomy and systematics
The spot-billed ground tyrant has three subspecies, the nominate M. m. maculirostris, M. m. niceforoi, and M. m. rufescens.Description
The spot-billed ground tyrant is long and weighs. The sexes have the same plumage. Adults of the nominate subspecies have an olive-brown crown, a whitish to buffy white supercilium and spot above their lores, a dusky line through the eye, and an olive to gray patch on the ear coverts on an otherwise whitish to dusky face. Their nape and back are olive-brown. Their wing coverts are olive-brown with buff to rufous edges. Their remiges are dusky to brownish with thin pale rufous edges. Their tail is dusky brownish to black with thin whitish or pale yellowish outer webs on the feathers. Their chin and throat are whitish, their breast and belly whitish with olive mottling or dusky streaking on the breast, and their undertail coverts whitish to white. With wear their upperparts fade to grayish and the wing covert edges pale. They have a narrow, sharp, medium-length blackish to brownish-black bill with a conspicuous yellow to orangish yellow base to the mandible. They have a dark brown iris and black legs and feet. Juveniles are essentially paler versions of adults, though the edges on their wing coverts are more rusty.Subspecies M. m. niceforoi has more light brown upperparts than the nominate, with blackish uppertail coverts. Their breast is slightly buffy and their belly pale pinkish buff with flanks a slightly darker pinkish buff. Their wings are dark brown with paler edges on the coverts and remiges. Their tail is blackish with whitish outer webs and blackish tips on the outermost feathers. M. m. rufescens is overall more cinnamon to pale rufus than the other two subspecies. Their underparts are cinnamon buff and the inner edges of their remiges are bright ochraceous.
Distribution and habitat
The three subspecies of the spot-billed ground tyrant are wholly allopatric. The nominate subspecies is the southernmost and has by far the largest range. It is found in the Andes from southern Amazonas and Cajamarca departments in northern Peru south through the rest of the country, reaching the coast in the southern part of the country. Its range extends through western and central Bolivia and along the entire length of the Andes of Chile and Argentina. Subspecies M. m. niceforoi is found locally along the Colombian Andes from southern Boyacá Department south to Cundinamarca Department and the Bogotá area. M. m. rufescens is found in the Andes of Ecuador from Imbabura Province south to Chimborazo Province and perhaps further south. There are is a record in far southern Colombia. In addition, the South American Classification Committee of the American Ornithological Society has records of vagrants of the species in Brazil.The spot-billed ground tyrant inhabits a variety of landscapes, all of which are sparsely vegetated and often rocky. The nominate subspecies occurs from the temperate zone all the way up to alpine areas, typically on slopes with rock walls and some grasses and shrubs. In Argentina is also occurs around saline lakes. In elevation it ranges between, though mostly between and as low as in Chile and Argentina. Subspecies M. m. niceforoi is found in dry open landscapes and agricultural areas below the páramo zone at elevations between. M. m. rufescens inhabits similar open, almost arid natural and agricultural landscapes, mostly between.