Very enjoyable gull situation at the Mission Creek outflow this afternoon. Inexplicably, there was hardly anyone on the beach, and the gulls were left largely undisturbed. I think 8 gull species were present, with the highlight being a 1st winter Thayer's Gull. Also present were a 1st winter Glaucous-winged Gull (though not certain of this ID, might be a second Thayer's - feedback welcome) and a 1st winter Herring Gull.
At Chase Palm, there was an adult Thayer's gull by the pond. And, on the fence at the edge of the desalination plant property (across the tracks), a Tropical Kingbird was present along with two Cassin's Kingbirds.