Hello, I photographed this gull at Cromer yesterday and I think I have photographed the regular 3CY bird there. The regular has brown streaking on the nape just like the bird in my photo. I just thought I would it put it on here for a second opinion (the first opinion was the local gull expert on Twitter and he said it looked good for the 3CY Casper) as this would be a lifer for me (although I almost definitely saw a juv Casper as well but I'm hopeless at juv gull ID).
Thanks,
Louis
Thanks,
Louis