Adult winter Thayer's Gull L. thayeri
December 24th 2001 Choshi Chiba Japan

This individual is a new face in Choshi.
The Thayer's Gull on the left, and 2 Vega Gulls.
Note the smaller size, very short legs and softer head markings. I noticed it is a Thayer's Gull as soon as I caught it sleeping in my telescope.
Then, its nice pale underwing appeared, just as I expected. When a Thayer's Gull stretches, its bill appears large seemingly. But really,  it is usually smaller than that of average Vega Gulls.