Greenish Elaenia Myiopagis viridicata

Unobtrusive and inconspicuous small flycatcher of tropical and subtropical forest; also ranges up into the highlands of West Mexico. Usually found singly, perched quietly (unless singing at dawn) and rather upright at mid-upper levels in trees; does not flick its wings and tail, unlike many small flycatchers. Can be identified by a combination of the lack of pale wingbars, a narrow whitish eyebrow, and the small, overall dark bill.