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
Western Kingbird
Tyrannus verticalis
Adults are a combination of both gray and yellow plumage, along with crimson feathers that are hidden until courtship or against intruders. Characteristic of kingbird species, the western kingbird is very territorial. Although the western is often misidentified as Cassin's kingbird, Couch's kingbird, or the tropical kingbird due to the yellow coloration, it can be distinguished from these other species through its black, squared tail with white edges.
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
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