Gelbscheitel-Olivtyrann Tyrannulus elatus

Small, small-billed flycatcher usually found in the canopy. Yellow belly with gray head and pale whitish eyebrow. Bold white wingbars. Namesake yellow crown is only sometimes visible. Sexes alike. Voice is the most obvious identification feature: listen for plaintive whistled song, “dee-DEER!” Seen singly or in pairs, usually in open forested habitats such as edges or second growth.