Cocos Tyrannulet

The Cocos tyrannulet is about 11 cm (4.3 in) long and weighs about 11 g (0.39 oz). The sexes have the same plumage. Adults have a grayish olive to dark brownish olive crown, a slightly paler supercilium and cheeks, and a thin dark line through the eye. Their upperparts are grayish olive to dark brownish olive. Their wings are dusky with dull yellowish buff edges on the flight feathers and tips on the coverts; the latter show as two wing bars. Their tail is dusky. Their throat and underparts are pale yellowish with a brownish to olive wash on the breast. Voice: As of late 2024 xeno-canto had no recordings of Cocos tyrannulet vocalizations and the Cornell Lab of Ornithology's Macaulay Library had eight. Males have two songs "an explosive, dry, descending chatter of 6–9 syllables, speeding up near end, and a series of low-intensity 'tic' notes followed by explosive trill of 7–10 syllables".