Mew Gull is one that I was a little worried about. Though we only saw them two days, we saw them in several locations our only day on the northern section of our coastal run (Morro Rock & San Simeon Coast). The other location, somewhat unexpected, was the Salton Sea.
THis basic adult is hanging around with California's. Mew's were a little bolder than I had expected, not backind down from the larger species; in particular they didn't mind moving a California or two around.