I guess Ikenaga-san learned a dear lesson: never try to take a picture of a Harlequin duck in its own element:-) He nearly got washed away when he tried to approach a drake which was resting at the end of a stone dam.
Description of adult winter plumage: Large gulls. Pink legs. Grey back with heavy streaks on neck and head. Yellow bill with red dot on lower mandible. Red ring around iris. One ex with dark yellow iris. Some individuals had brown eyes. Others pale yellow. I find this a hard feature to observe: pale eyes are no problem, but with the darker eyes one worries often whether one watches true color or a mere shadow. (the grey of the L.a.v. is clearly less than that of L. crassirostris.)
Description of adult winter plumage: Size similar to L. a. vegae. Yellow legs, or yellow-orange. Upper part of feet sometimes pink. Color of back without doubt a bit darker. Streaking of head and neck less and lower, making the head more white. Shape of the head rather angular (upside down sketch \__/.) Yellow bill with red dot on lower mandible. Some with yellow iris. Color of ring around iris was dark, I am not sure about true color. One ex seemed to have a darker colored eye, however this was difficult to observe due to a rather pronounced orbital rim, i.e., an overhanging edge of skul, making the facial expression rather aggressive.
Description of adult winter plumage: Smaller than L. a. vegae with top of head reaching just to the bill of L. a. vegae. Legs without doubt lighter pink than surrounding L. a. vegae. Color of back identical to color of back of L. a. vegae. Streaking as L. a. vegae, perhaps les dark. Head appeared to be very flattened (upside down \___/) so that the distance top of the skul and eyesocket seemed to be relatively little. Yellow bill with red dot on lower mandible. Eye appeared to be dark.Discussion: Thayer's gull is supposed to have dark pink legs. (see ID-Frontiers) and picture in "A Guide for Bird Lovers". Nick Lethaby comments: " I don't see anything about this description that suggests a Thayer's Gull. It's essential to study the wing-tip pattern in detail from above and below. Also Thayer's tends to have a rather rounded head shape. The only Thayer's I saw in Japan appeared slightly paler on the mantle than vegae, although vegae is very variable."