After spending the afternoon finding nothing unusual at Los Vaqueros, I got to Clifton Court Forebay late this evening, and started scanning the massive gull flock after sunset. However, in about 25 minutes of gulling before it got too dark, I was able to pick out an adult-type LESSER BLACK-BACKED GULL and at least one 1st-cycle GLAUCOUS GULL.
They were both viewed by looking northeast into the gull flock from the end of the rounded point of land about a mile north of the parking area.
Clifton Court is a gull roost, so gulls are probably mostly there in the late afternoon and evening. If it’s anything like the other roosts I’ve gulled, there will probably be a flock of gulls there by mid-afternoon, with numbers increasing until sunset. (Note that the parking lot is closed at 6pm, so don’t stay too far out there too late.)
I think this Lesser Black-backed is a long-overdue county first...?
Noah Arthur (Oakland)