Cassin's Kingbird
Tyrannus vociferans
Adults have a gray head with slightly darker cheeks; a dark unforked tail with a buffy fringe and gray-olive underparts. They have a pale throat and deep yellow lower breast. Juveniles are duller and have pale edges on their wings. Measurements: Length: 8.3–9.1 in (21–23 cm) Weight: 1.6 oz (45 g) Wingspan: 41 cm Cassin's kingbird and the western kingbird are similar in appearance. Cassin's is a little larger than the western and the upper parts are a darker gray than the western.
ID text from Wikipedia, CC BY-SA 4.0
Tropical Kingbird
Tyrannus melancholicus
An adult tropical kingbird is 22 cm (8.7 in) long, weighs 39 g (1.4 oz) and has a wingspan range of 38–41 cm. The head is pale gray, with a darker eye mask, an orange crown stripe, and a heavy gray bill. The back is grayish-green, and the wing and forked tail are brown. The throat is pale gray, becoming olive on the breast, with the rest of the underparts being yellow. The sexes are similar, but young birds have pale buff edges on the wing coverts.
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
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