I was at West Beach in Deception Pass State Park yesterday. This Glaucous-winged Gull (Larus glaucescens) agreed to stand nicely for his portrait. I can add this photo to my collection of "seagulls standing on rocks." This must reveal some unique behavioral characteristic, but I have not yet figured it out. Whatever is going on, it certainly adds to the charm of these common shorebirds.
Pink feet and a red spot on the bill are identifying characteristics. A similar, less common local bird is the Western Gull (Larus occidentalis). The Western has black wing tips with white spots, while the Glaucous-wingeds have gray wing tips with white spots. This is complicated by the fact that these and several other gull species will interbreed producing hybrids. In general, gulls are extremely difficult to differentiate. As we get further into fall and winter, the head and neck of these birds will take on brown mottling.
In natural areas, Glaucous-winged Gulls like to nest on the low, rocky islands that dot our local waters. In urban areas, they will nest on rooftops. I have noticed that country birds tend to be quiet and peaceable, while their urban counterparts can be noisy and aggressive. According to iBird, a group of gulls may be a "flotilla," "gullery," a "scavenging" or a "squabble."