Southern Beardless Tyrannulet

The southern beardless tyrannulet (Camptostoma obsoletum) is a small passerine bird in the tyrant flycatcher family. It breeds from Costa Rica through South America south to Paraguay, Bolivia, and Argentina. The southern beardless tyrannulet is 10.2 cm long, weighs 7.5 g and often resembles a tiny yellow-bellied elaenia. The head is dark brown or grey with an erectile crest and pale supercilium. The upperparts are grey-green becoming paler on the rump. The wings are brown with yellow feather-edging and two whitish, yellowish or cinnamon wing bars. The tail, which regularly is held cocked, is brown, the throat grey, the breast yellowish, and the abdomen yellow. The bill is black, but at least the base of the lower mandible is pale.