Thayer's/Kumlien's Gull Larus thayeri / L. glaucoides kumlieni
January 30th and February 28th 2012 Choshi Chiba Japan
This gull also seems to be the same individual as another one considered as kumlieni in 2009 ('Sangou'). This also has grown into a darker bird than we expected, and currently looks like a hybrid/intergrade between thayeri and kumlieni. We will keep our eyes open to watch next year whether this individual will get paler than this or not.
The same individual on February 28th.