All,
I went to Bayfront Park this afternoon arriving about 1620. As I walked out the northern spur that points to the High Level Bridge
a loose group of about 30 gulls came soaring and gliding overhead. One was clearly a white-winged gull - with white underprimaries.
I kept looking at it because of what I was doing there and because it had a robust all-black bill. As it glided away from me heading towards
the North Shore of the Bay I was now able to see the upperside. It had grey-brown primaries concolorous with the mantle. There was a broad grey-brown tail band, essentially the entire tail, which contrasted with a white rump. The bill continued to look large and black. The bird appeared quite stocky.
To my mind and as I look at photos the only species this might be confused with are a dark second cycle Thayer's Gull or a very dark "Kumlien's Gull".
Both those birds are less robust than this bird was. The bill was too robust and the tail rump contrast too great for those "species".
I think it went down with the other birds over towarss Holy Sepulchre Cemetery. I went over to the yaught club to make sure that it hadn't circled back. It hadn't; there was one first cycle Glaucous Gull on the docks.
Bob Curry