1st winter/summer
Mongolian Gull L. c? mongolicus
March 25th 2002 Choshi Chiba Japan

Note the white underparts and long black bill that resemble cachinnans

But the wing coverts are also whitish. Therefore 1st winter/summer Mongoian gulls often tend to be extremely whitish birds.

With 3 Slaty-backed Gulls and a Black-tailed Gull. The Mongolian Gull looks whiter than a pale Slaty-backed Gull on the left. Note the long legs.

Note the narrow black band and white base of outer tail feathers.

Vega Gull L.vegae
March 23rd 2002 Sakawagawa-river Odawara Kanagawa Japan

This is a typical example of Vega Gull. Note the obviousely browner appearance in late March.