Gray-capped Tyrannulet Phyllomyias griseocapilla

Tiny flycatcher with a short bill and a long tail. It has an olive-brown back with a gray head and an “open” whitish face without a strong eyebrow. Its belly is white with yellow flanks. Also note the yellow edged primaries. Found in humid forests and second growth, occasionally following mixed-species flocks. The song is a high-pitched whistle “weee-weee.”