I thought this picture, taken at the mouth of the Salinas River, might show a juvenile Common Tern, taking account of the mixed orange and black bill, the solid black nape with white forehead, and what appears to be the dark leading edge of the far wing. Unfortunately the picture doesn't show much of the the upperparts. Forster's Terns are much more usual here, and I was not positive this is the relatively rarer bird. Advice welcome! UPDATE: Response so far indicates that this is definitely not a Forster's Tern -- most probably a juvenile Common, given the dark leading edge, but just possibly a (much rarer) juvenile Arctic Tern, given the relatively short bill.