Glaucous-winged x Western Gull hybrid pair
The bird in the back looks almost like a Glaucous-winged Gull but note the dark areas in the primaries
The bird in the front has darker primaries like a Western Gull but note their waxy, slate-gray color and the shape of the head and bill which closely resemble Glaucous-winged Gull

Westport Marina WA
March 2011