Description wikipedia

The warbling doradito (Pseudocolopteryx flaviventris) is a species of bird in subfamily Elaeniinae of family Tyrannidae, the tyrant flycatchers. It is found in Argentina, Paraguay, Uruguay and Brazil. The warbling doradito is 11 to 12 cm (4.3 to 4.7 in) long and weighs 7 to 8 g (0.25 to 0.28 oz). The sexes have the same plumage. Adults have a mostly dull olive-brown head and upperparts. Their crown is rufescent, their lores and cheeks are dusky, and their tail is dusky olive-brown. Their wings are dull olive-brown with light buffy edges on the flight feathers and tips on the wing coverts; the last show as two faint wing bars. Their throat is bright yellow and their underparts a slightly less bright yellow. Both sexes have a medium brown iris and dark gray legs and feet. Males have a slender, black, warbler-like bill; females have a mostly black bill with a pale pinkish base to the mandible. Juveniles are duller overall than adults; their wing bars are a deeper buffy, their throat grayer, their breast bright buffy, and their belly creamy yellow.