Nice look again at the contrast in the outer and inner webs of the outer primaries of the Thayer's wheeling around in the upper corner. Of interest in shot also is how much dark there is in the primaries of the 1st-cycle Herring Gull in the lower corner. Compare this to the couple of shots I have of the underwing of the Thayer's.

Sorry these photos aren't better, but this at the edge of the range of a 400mm lens. I was quite happy, and surprised, to have gotten what I got.