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Illinois. February. |
Age: This appears to be a 1st cycle large gull, based on the mottled grayish-brown upperparts with extensive patterning, black bill and consistently patterned uppertail coverts.
Identification: With so many similar-looking large gulls in 1st cycle, where does one begin? Importantly, the outer primaries have a distinct two-toned appearance, often described as a venetian blind pattern. The plumage is fairly uniform, grayish-brown, and not very contrasty (as we find in California and Herring Gull). The warmer brown tones to the flight feathers, including the tail feathers, fairly straight bill -- and of course location -- all point to a 1st cycle Thayer's Gull (Larus glaucoides thayeri), which is what our December 2024 Quiz bird is.