Rufous-crowned Tody-Flycatcher
Poecilotriccus ruficeps
The rufous-crowned tody-flycatcher is about 9 to 10 cm (3.5 to 3.9 in) long and weighs about 6.6 g (0.23 oz). The sexes have the same plumage. Adults of the nominate subspecies P. r. ruficeps have a bright rufous crown and a gray nape that are separated by a black line that continues onto the cheek. They have a white to buffy area above the lores, a thin black line through the eye, and white to buffy cheeks. Their back, rump, and uppertail coverts are olive. Voice: The rufous-crowned tody-flycatcher's vocalizations are "soft, easily overlooked, and usually given only at well-spaced intervals". Its song has been described as a sputtering "pa-treer-pít-pít-pít" with some variation. Its calls include "a gravelly stuttered 'tttrew', 'pit-tttrew', or 'tttrew-pit', sometimes given as a duet".
ID text from Wikipedia, CC BY-SA 4.0

Slaty-headed Tody-Flycatcher
Poecilotriccus sylvia
The slaty-headed tody-flycatcher is about 9 to 10 cm (3.5 to 3.9 in) long and weighs 6.7 to 8.5 g (0.24 to 0.30 oz). The sexes have the same plumage. Adults of the nominate subspecies P. s. sylvia have a gray crown and nape. Their lores are gray; they have a white line above the lores and a broken white eye-ring on an otherwise gray face. Their back, rump, and uppertail coverts are olive. Their wings are blackish with narrow yellowish edges on the inner flight feathers and large yellow tips on the coverts; the latter show as two wing bars. Their tail is olive. Voice: According to Hilty, the slaty-headed tody-flycatcher's vocalizations are "insect- or froglike". They include "a soft, gravelly trup or trup grrrr, varying to tik trrrrrrr; nasal froglike grrrrrrr also given singly. When excited tíc-a-turrr". Fagan similarly describes one call as "a 2-part tip!-purrrrrrrr".
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
Learn this pair in the BeakBrain App
Photo and call practice. Coming soon to iPhone and Android.
Play today's Daily BirdPhotos and recordings are credited to their authors under the licence shown. Full profiles: Rufous-crowned Tody-Flycatcher and Slaty-headed Tody-Flycatcher.