Ring-billed gulls are frequent vagrants to the UK, although my home county of Northumberland has not had many (rather amusingly the first bird I saw in the UK/Northumberland was in company with a laughing gull larus atricilla at Newcastle General Hospital many years ago...). I love the yellow iris with piercing black pupil!
California gull seemed to be less abundant at Santa Monica than RBG, and ony a few photographs were obtained. The winter adult featured here shows the relative long winged profile, dark iris and grey-green legs.
