possible 1st-cycle Slaty-backed in San Leandro

Noah Arthur

Jack Hayden and I watched a 1st-cycle gull showing many characteristics of Slaty-backed Gull in the northernmost parking lot at the San Leandro Marina today. I saw this same bird on the 16th, but only today did I get good photos of the tail in flight, which show fairly extensive white at the tail-base, unlike Glaucous-winged, Western, and Glaucous-wingedXWestern hybrids. There are some dark splotches on the back, but it's hard to tell if these are actual adult gray feathers, or just well-marked post-juvenal feathers. The internet connection is acting up right now; I'll try to post some pictures tomorrow.
Noah Arthur, Oakland

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