Western Gull, Juvenile: Central Park, San Francisco, California, USA - 13th November 2009

Note the overall uniform brown tones.

presumed Western x Glaucous Gull, juvenile: Laguna Park, San Louis Obisp, California, USA - 23rd November 2009

This juvenile bird included here as example of a probable hybrid. The bulbous all black bill, the head shape, the dark head, neck and body tones and well marked wing coverts indicate Western Gull however the juvenile scapulars have whitish fringing giving the bird a slightly 'frosty' appearance above and the primaries, although dark, are not blackish. It is most likely this is a hybrid bird which could be overlooked as a Western based on the darkish body colour.