American Herring Gull  Larus smithsonianus
Mar. 28th 2011 Tokyo Imperial Palace Japan 

This American Herring Gull suddenly came into the flock of Vega Gull on the water. This is the first American Herring Gull I observe at Tokyo Imperial Palace.


Note the yellow orbital ring.


The primary shows extentive black (reaches to P4 in this individual) . It is an important feature to rule out VegaXGlaucous hybrid, especially in Japan.


The American Herring Gull on the left with Vega Gulls and Black-headed Gulls.


The American Herring Gull on the left with Black-headed Gulls.
The mantle shade looks only a little darker than in Black-headed Gulls.


The American Herring Gull (center) with 2 Vega Gulls.