ANSWER...when its like this little bugger
Cracking 'ringed-billed Gull' or to be precise a moulting adult winter Common Gull (prey to god I'm right) that just happens to be wearing some bling. A trap me thinks for the uninitiated. Be careful out there chaps!
Here's a proper blinged up Ringer from Holland/Belgium...
That would look tasty on The Bank what?