Look closely! See that bright red spot on the bill. That is known as a breeding spot. It appears on sexually mature and active male and female Glaucous-winged Gulls at this time of year. (Ain’t that a ten pound name for a gray wing?) The breeding spot really has not much to do with breeding. Rather, the small spot near the end of the bill is associated with chicks feeding. They peck at it in order to stimulate feeding.
One of the fun challenges of identifying these gulls is the hybridization that occurs with the Western Gull (Larus occidentalis) in Puget Sound. In Alaska it is the Herring Gull (Larus argentatus)that can mate with them.