Marble-faced Bristle Tyrant

The marble-faced bristle tyrant is about 11.5 to 12 cm (4.5 to 4.7 in) long and weighs 10 to 11 g (0.35 to 0.39 oz). The sexes have the same plumage. Adults of the nominate subspecies have a slate-gray crown, white lores, and a white supercilium on an otherwise gray and white grizzled face. Their ear coverts are white to very pale yellow with a black crescent at the rear. Their back and rump are bright yellow-olive. Their wings are dusky with pale olive-yellow to yellow edges on the flight feathers. Their wing coverts are dusky with pale olive-yellow to yellow tips that show as two wing bars. Voice: The marble-faced bristle tyrant's vocalizations vary somewhat among the subspecies. In Venezuela (P. o. purus) the song is "a bubbly trill...ju-E, pit'pe'e'e'e'e'a'a'a'e'e'e'e'e'e'pit'pit . .ju-E" and its contact call "a brief ju-E!". In Ecuador the nominate sings "a fast psee-ee-ee-ee-u, tsi-tsi-tsi" and its call is "a doubled ts-rt". In Peru P. o.