Vega Gulls Larus vegae
December 22nd 2007 Choshi Chiba Japan
A very fresh, dark juvenile. But note that greater coverts are not dark like smithsonianus.
The overall coloration and marking somewhat resembled Thayer's Gull. But its size and structure clearly indicated Vega Gull.
This unusual double narrow tail band recalled Mongolian Gull from a distance. But at rest, it looked like a normal Vega Gull.
The dark outer greater coverts and slim overall structure may indicate 'taimyrensis' .
Another similar example as above.
A flock of 1st cycle large gulls (mainly Vega and Slaty-backed) in Japan generally looks brownish from a distance, compared to a 'frosty' flock of Mongolian Gull in China or west coast of Korea.