Rufous-browed Tyrannulet

The rufous-browed tyrannulet is 9.5 to 12 cm (3.7 to 4.7 in) long; three individuals weighed 7 to 9 g (0.25 to 0.32 oz). The sexes have the same plumage. The forecrown and lores of nominate adults are bright chestnut that extends to the rear as a thin supercilium. They have a small white spot at the base of the bill. Their ear coverts are white with a thin but conspicuous black border and the rest of their face is grizzled whitish. Their crown is pearly gray and the rest of their upperparts are bright olive. Their wings are dusky olive with yellowish green edges on the flight feathers. Voice: The rufous-browed tyrannulet's song is variously described as a "lively and arresting...wiss, wreewreewreewreewree and wree tititititi", "a spritely spee-ee-ee-ee-ee, spee-dididee", and "a high, springy, laughing chatter that quavers: chi chi tchrrEE'EE'ee'EE'EE'eew or shorter tchwee tchwee ti-titititew". Its call is "a sharp, emphatic screesh" or "a high tchwee".