Southern Tropical Pewee

The southern tropical pewee is 13.5 to 14.5 cm (5.3 to 5.7 in) long and weighs about 10 to 15 g (0.35 to 0.53 oz). The sexes have the same plumage. Adults of the nominate subspecies have a dark blackish gray crown with a slight crest, white to grayish white lores, and a thin white eye-ring on an otherwise grayish olive face. Their back is sooty olive-gray and their rump and uppertail coverts brownish olive with a hidden white feather tuft on either side of the rump. Their wings are mostly dusky. The wing's secondaries have white to brownish gray edges at the ends and the median and greater coverts have grayish white to brownish gray tips that show as two thin wing bars. Their tail is olive-gray. Their chin and throat are white, their upper breast white with a gray tinge, their lower breast and belly white to yellowish white, and their undertail coverts pale brown. Juveniles have browner upperparts than adults with buff to cinnamon-buff edges on the feathers. Their wing coverts have wide pale cinnamon-buff tips. Their chin is brown. Subspecies C. c. pallescens has a darker crown than the nominate but is otherwise the same. Both subspecies have a dark brown iris, a sepia brown maxilla, a paler and more orangey mandible, and sepia-brown legs and feet.

Subspecies C. c. pallescens of the southern tropical pewee is the more northerly of the two. It is found in central and eastern Brazil roughly bounded by southern Maranhão, Pernambuco, and Mato Grosso do Sul and south through eastern Bolivia and northern Paraguay into northwestern Argentina as far as Tucumán Province. The nominate subspecies is found in southeastern Brazil from Bahia to Santa Catarina and south through central and southeastern Paraguay into northeastern Argentina's Misiones Province. The species, as what is thought to be C. c. pallescens, also occurs as a rare migrant in southeastern Peru. The southern tropical pewee inhabits a variety of semi-open landscapes including light woodlands, secondary woodlands, plantations, and the edges of semi-deciduous forest. In elevation it mostly occurs below 1,300 m (4,300 ft) but reaches 1,800 m (5,900 ft) in Brazil, 2,000 m (6,600 ft) in Argentina, and exceptionally to 2,850 m (9,400 ft) in Bolivia.

The southern tropical pewee apparently feeds only on insects, though details are lacking. It typically forages singly or in pairs. It sits erect on a somewhat open or exposed perch on the forest edge, usually no higher than the forest's mid-level, and captures prey in mid-air with sallies from it ("hawking"). It usually returns to the same perch after a sally and "shivers" its tail upon landing. It rarely joins mixed-species feeding flocks.