Black-throated Green Warbler
Setophaga virens
It has an olive-green crown, a yellow face with olive markings, a thin pointed bill, white wing bars, an olive-green back and pale underparts with black streaks on the flanks. Adult males have a black throat and upper breast; females and immature males have a pale throat and black markings on their breast. Measurements: Length: 4.3–4.7 in (11–12 cm) Weight: 0.3–0.4 oz (8.5–11.3 g) Wingspan: 6.7–7.9 in (17–20 cm)
ID text from Wikipedia, CC BY-SA 4.0
Pine Warbler
Setophaga pinus
These birds have white bellies, two white wing bars, dark legs and thin, relatively long pointed bills; they have yellowish 'spectacles' around their eyes. Adult males have olive upperparts and bright yellow throats and breasts; females and immatures display upperparts which are olive-brown. Their throats and breasts are paler. The adult male pine warbler looks somewhat similar to the yellow-throated vireo which may cause some identification problems. The song of this bird is a musical trill. Their calls are slurred chips.
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
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