Yesterday and today there's been a spectacular herring spawn event occurring at Agua Vista Park (just north of Mission Rock Resort) on the SF Bayside. Large quantities of roe on the rocks are attracting thousands of gulls, including MEW, CALIFORNIA, WESTERN, GLAUCOUS-WINGED, AMERICAN HERRING, THAYER'S, and HEERMANN'S GULLS, plus various hybrids. I spent most of today scanning through the flocks looking for 'something different'. Among the many Thayer's Gulls (mostly pale birds) were at least two adults that looked possible for 'Kumlien's' Iceland Gull, but I need to work on the ID's more, and I'm definitely not calling them Iceland for sure yet...
I have no idea how long this herring-roe feast will last... But if it continues, it seems likely that some nice rare gulls will show up this week...
Oakland, CA/Lincoln, NE