First-cycle Thayer's Gull (center). Note dark brown primaries, much darker than tertials or tail band.
About two and a half hours after I lost track of the Slaty-backed Gull, a tremendous number of resting and bathing gulls had built up at Niles Pond. I'd positioned myself close to an open spot in the ice where the gulls were bathing and could hardly believe my luck when last weekend's Thayer's Gull from Gloucester Harbor popped-up right in front of me! It gave exquisite views, and this time I got some reasonable flight shots through my bins. The Thayer's situation at Niles Pond today was simply amazing. I had three 1st-cycle birds, and the probable 2nd-cycle from December 30th. I think all except one had been recorded before by either Erik Neilson, Marshall Illiff, and myself with Brian Kane last week. Sadly, none of the other three birds offered the same photographic opportunities as this one.
NB. I'll be adding a few annotations to these pics soon.