Yungas Tyrannulet

The Yungas tyrannulet is 10 to 11.5 cm (3.9 to 4.5 in) long. The sexes have the same plumage. Adults have a dull olive-gray crown and nape with a slightly mottled appearance. Their lores, supercilium, partial eyering, and lower face are whitish with a dark stripe through their eye. Their upperparts are yellow-olive that becomes paler and more yellowish on their rump and uppertail coverts. Their flight feathers are fuscous to dusky brown with pale yellowish to creamy edges. Voice: The Yungas tyrannulet's song is "a slightly accelerating series of 3–5 whistled notes successively dropping in pitch, first note longest". Pairs also sing an antiphonal duet with one member singing a short burry note and the other a more complex series of notes.