black-capped pygmy-tyrant Myiornis atricapillus

Tiny short-tailed flycatcher, one of the smallest songbirds in the world. Similar shape and size to a golf ball. Blackish cap, greenish back, and dirty white underparts. Look for white spectacles. Can be quite difficult to spot even when calling nearby. Sometimes high in the canopy but can also be seen quite low. Prefers forest edges and second growth.