Tim and I swung through the south county earlier. We spent some time at the Forest Lawn landfill and were just about to leave when he picked an adult California Gull off the front face. The bird stayed just long enough for me to get a look through his scope before the entire flock took off.
It turns out it's there more or less centered, the upper left corner of the inset points to it.
Fortunately the birds took off again, though this time more slowly. Nevertheless, if you think it's easy to follow one essentially identical gull out of at least 500 others through a chain-link fence and a view-finder with birds milling in both directions and clouds of starlings periodically chaffing the target, well feel free to try it.
If you decide you want to try your luck, make sure you sign in at the landfill office. This was the 3rd California Gull I've seen in Berrien; the county accounts for more Cal Gulls than the rest of the state combined.