Chroicocephalus near Old Sow, Deer Island Canada 22 August

[Carol Muth]

I posted a photo taken from the Welshpool Ferry of a small gull flying among many Bonaparte's Gulls yesterday. It's probably a Bonaparte's, but it has red legs, not a lot of black edging on wing, and none on tail. It's possible that the light on water distorted the markings or their color. In case it is the Black-Headed Gull, I'm asking for anyone interested to take a look. It's on iNaturalist (so I could make comments and explanations and get feedback). I posted the observation as "Croicocephalus" but iNaturalist  calls it "Masked Gulls". You can look for my posts in the "explore" link to carol-in-maine, or look for the species. You don't need to be a member to look at observations, just to make comments, and you can do that here on this list if you recognize the bird. Thanks!