Thayer's Gulls Larus thayeri
March 22nd 2013 Tokyo Imperial Palace Japan
This is a small/small-billed, relatively dark-winged Thayer's Gull that is probably the same individual as a 1st winter bird found in 2012.
With an adult Thayer's Gull in the background.
Comparison with presumed the same individual in 2012.
Intergrade/hybrid with kumleni?
Another 2nd winter bird that has been regular here since previous winter. At first glance in flight, this bird looks very like Glaucous-winged Gull in coloration. But its short-billed/long-winged structure indicates it belongs to Thayer's-Iceland complex.
The outer primaries are darker than the inner ones, unlike Glaucous-winged Gull.
Presumed the same individual in 2012