Common Tody-Flycatcher (Todirostrum cinereum)
ProAves Cerulean Warbler Reserve, San Vicente de Chucuri, Santander, Colombia Note white eye. Small and fast, and often seen near a hanging nest.
Note dark eye, white throat, and especially yellow back vs. the Common Tody-Flycatcher. Tends to stay in the canopy with a single-note song/call.
From front.