Alder Flycatcher
Empidonax alnorum
E. alnorum is one of the larger Empidonax species, attaining a length of 13–17 cm (5.1–6.7 in), and a weight of 12–14 g (0.42–0.49 oz). The wingspan ranges from 21–24 cm (8.3–9.4 in). The upperparts of E. alnorum are dull greenish-olive. The crown is a slightly darker olive-green than the back. The throat is white, with a darker breast band. Thin white rings surround the eyes. The bill is wide and moderate in length, with pinkish or yellow-orange lower mandible and black upper mandible. Wings are generally black, with white wing bars and white edges of the innermost secondaries (tertials). Voice: The vocalizations of the alder flycatcher are very useful for its identification in the field. The song is a distinct "fee-bee-o"; birds have been observed to throw their heads back and shake their tails while singing. There are a variety of calls made, the most common of which is a "pit" sound produced when foraging.
ID text from Wikipedia, CC BY-SA 4.0
Yellow-bellied Flycatcher
Empidonax flaviventris
Adults have greenish upperparts and yellowish underparts (especially on the throat), with a dusky wash on the chest. They have a white or yellow eye ring that lacks the teardrop projection of the western flycatcher, white or yellowish wing bars that contrast strongly against the black wings, a broad, flat bill, and a relatively short tail when compared to other members of the genus. The upper mandible of the bill is dark, while the lower mandible is orange-pink.
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
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