If you want to see 1000+ more Western Gulls (Larus occidentalis) taking wing in San Francisco County, head on over to Alcatraz, where half the place seems to be a nesting colony. The things are everwhere these days.
They’re hanging about all over:
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And why not? They’re protected from any kind of threat you’d imagine.
Verily, Alcatraz Island is a kind of Paradise, a resort island for gulls.