Yellow-margined Flatbill
Tolmomyias assimilis
The yellow-margined flatbill is 13 to 13.5 cm (5.1 to 5.3 in) long and weighs 12 to 17.5 g (0.42 to 0.62 oz). The sexes have the same plumage. Adults of the nominate subspecies T. a. assimilis have a mostly olive-tinged gray head with a thin white broken eye-ring. Their back, rump, and uppertail coverts are olive-green. Their wings are dusky with yellow edges on the greater coverts and remiges that appear as a pale speculum and a faint wing bar on the closed wing. Their tail is dusky. Their throat is pale gray, their breast and flanks pale olive, and their belly pale yellow. Voice: The yellow-margined flatbill's vocalizations vary geographically. In the Guianas it makes a "series of typically 2‒5 drawn-out extremely nasal, almost screaming notes". In Ecuador it sings "a leisurely series of 3 whistled notes, each slightly higher-pitched and shriller, e.g. weeeuw...weeeu...weee?
ID text from Wikipedia, CC BY-SA 4.0
Yellow-olive Flatbill
Tolmomyias sulphurescens
The yellow-olive flatbill is 12.5 to 14 cm (4.9 to 5.5 in) long and weighs 14.5 to 15.2 g (0.51 to 0.54 oz). The sexes have the same plumage. Adults of the nominate subspecies T. s. sulphurescens have a dark olive crown and nape, a thin white band above the lores, a thin white eye-ring, and pale olive ear coverts with a dusky patch at their rear. Their upperparts are olive-green. Their wings are dusky or blackish with yellowish-olive edges on the wing coverts that form two wing bars. Their remiges have yellowish edges. Their tail is brownish to dusky with buffy edges on the feathers. Voice: The yellow-olive flatbill's song varies widely among the subspecies. That of T. s. cinereiceps is a "series of 4 thin insectlike buzzes, zeee-Zeee-Zeee-ZEEEE!" and its call a "shrill, sibilant tssssp". In western Ecuador T. s. aequatorialis sings "a thin and well-enunciated series of quick notes, 'psee-pset-pset-pset' ". In northern Venezuela T. s. exortivus gives a "buzzy bzz...bzzz...
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
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Play today's Daily BirdPhotos and recordings are credited to their authors under the licence shown. Full profiles: Yellow-margined Flatbill and Yellow-olive Flatbill.