A reader took these photos this weekend on the CT shoreline. That is the common Ring-billed Gull (sometimes known as the Parking Lot Gull), an inland, fresh-water breeder. They head for the coasts when the fresh waters freeze up.
Gulls take seveeral years to reach maturity and to earn adult plumage. These, I think, are second-year Ring-billed gulls hunting in the surf. First year birds would have a darker brown plumage:
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And a good portrait: