I assume this is a ubiquitous Herring Gull. But when I looked closely at the combination of red and black markings on the bill, the lack of any streaking on the neck, and the reddish orbital ring it wasn't a perfect match to Sibley's description (but then, neither was anything else). Is it just a normal variation of Herring Gull markings? This was taken yesterday at Barnegat Lighthouse on the New Jersey shore.
Looks like a Herring Gull to me Bill. In my experience, younger birds show dark on their bills and this can be retained in birds just transitioning to full adult plumage. The lack of streaking means this bird has moulted into its Alternate or breeding plumage.
Why do I now have the feeling that the hotshot birdwatchers on BPN are going to tell me I'm all wrong?!!