Guianan Tyrannulet

The Guianan tyrannulet is 9 to 12 cm (3.5 to 4.7 in) long and weighs 5.7 to 11 g (0.20 to 0.39 oz). The sexes have the same plumage. Adults have a gray forehead and crown. They have a thin whitish supercilium that starts at their lores and a dark stripe through the eye on an otherwise almost pure white face. Their back and rump are dull olive. Their wings are dusky with thin yellow edges on the coverts and inner parts of the flight feathers. Their tail is dusky olive. Their throat is almost pure white, their breast pale olive-yellow, and their belly and undertail coverts pale yellow. Adults have a gray or dark brown iris, a small, rounded, black bill, and dark grayish legs and feet.

The Guianan tyrannulet is found in eastern and southeastern Venezuela's Bolívar state and east across the Guianas and northern Brazil to the Atlantic in Ceará and south to northern Mato Grosso. There are also isolated populations in far eastern Brazil's Rio Grande do Norte to Alagoas states. It inhabits humid forest in the tropical zone, where it occupies both terra firme and várzea landscapes. In unbroken forest it typically is found in the canopy and at clearings and edges. It is occasionally found above 500 m (1,600 ft) in Brazil; it mostly occurs below 1,000 m (3,300 ft) in Venezuela but has been recorded up to 1,400 m (4,600 ft).

The Guianan tyrannulet feeds on insects and small fruits, especially those of mistletoes (Loranthaceae). It forages singly or in pairs and sometimes joins mixed-species feeding flocks. It feeds mostly in the forest canopy, actively moving about and gleaning food while perched or with short flight.