Tiny short-tailed flycatcher. Yellow below with white eyebrow that wraps around the forehead. No wingbars. Very similar to Yellow-bellied Tyrannulet, but note brown crown (not gray). Voice is also distinctive: a series of plaintive clear whistles descending in pitch. Found singly or in pairs, usually in the forest canopy, where it can be difficult to spot given its small size. Sometimes joins a mixed-species flock.