Heuglin's Gull Larus heuglini
February 15th 2008 Choshi Chiba Japan
This individual seemed to be within the range of heuglini, though heuglini and 'taimyrensis' seem to be clinal and not always safely distinguishable.
The Heuglin's Gull (foreground) with a Vega Gull (background).
Note the solidly dark primaries lacking pale 'window'.
A Heuglin's Gull in Oman.
An example of 'taimyrensis' in Choshi . Both indistinct pale 'windows' and dark greater covert bars are visible in flight.
A typical Vega Gull. Note the large, distinct 'window' on primaries and greater coverts lacking dark bars.