Buff-cheeked Tody-Flycatcher Poecilotriccus senex

Very small, poorly-known flycatcher. Note the buff lores and streaked throat. Has a gray crown, an olive back, and white underparts. Found at the edges of humid forest, often along black-water rivers and in low-stature white sand forests. The song is a short deep trill, sometimes preceded by “tick” notes.