Yellow-crowned Elaenia

The yellow-crowned elaenia is 12.5 to 13 cm (4.9 to 5.1 in) long and weighs about 12 g (0.42 oz). The sexes have the same plumage. Adults have a dark brownish olive crown with a large but partially concealed bright yellow stripe along its middle. They have an indistinct whitish loral spot and supercilium; their lower face is grayish olive. Their upperparts are olive. Their wings are dusky olive with bright yellow edges on the inner flight feathers and tips on the coverts; the last form two bars on the closed wing. Their tail is olive. Their throat is whitish, their breast yellow with an olive wash, and their belly bright yellow. Both sexes have a dark brown iris, a short black bill with a pinkish base to the mandible, and gray legs and feet.

The yellow-crowned elaenia has a disjunct distribution. One population is found in the northeastern Venezuelan states of Monagas and Delta Amacuro. Another is found in the southern Venezuelan state of Amazonas and very slightly into Guainía Department in extreme eastern Colombia. A third is found in Sucumbíos and northern Orellana provinces of northeastern Ecuador, the northeastern quadrant of Peru, and slightly into far western Brazil. The fourth population has the largest range. It is found across the Guianas north of the Guianan Shield into northeastern Brazil and along the Amazon and its tributary the Madeira River from Amazonas state and Rondônia east to the Atlantic. The species primarily inhabits várzea and swampy flooded forest along large watercoureses. In Venezuela and the Guianas it also inhabits flooded forest growing on sandy soils. In elevation it reaches from sea level up to about 300 m (1,000 ft).

The yellow-crowned elaenia's diet has not been studied, but it is known to include insects. It typically forages singly or in pairs in the forest understory to mid-story, and seldom joins mixed-species feeding flocks. It typically captures prey from vegetation with short sallies from a perch.