This HERG-type gull was photographed at a landfill in Houston, Texas on December 14, 2005 - note that it had been raining heavily for a long time previously, and some of the head feathering appeared to be rather matted-down; it was the size of a medium-to-largish HERG:
Note below the somewhat isolated white line along the inner 2/3rds of the upper marginal wing coverts, on the far wing:
