These pics (taken late Feb) were submitted to the TBRC as part
of the documentation for a 1st-Basic L. thayeri (visible
near the top of the first photo and again in the bottom picture).
I am interested in the bird in the bottom-right of this photo;
the "retarded 3rd-Basic" type between two Ring-billed
Gulls. My first impression was of a thick-set californicus,
but there is indication that the eye is pale, plus it may be
too large for californicus; yet it looks very small, too
long-winged (or short-tailed), and rather dark for smithsonianus.
Mantle color can be misleading, but this gull seems to be at
the same angle as those nearby, and in every photo it appears
one shade darker (and maybe less bluish) than the RBGUs - much
closer to LAGU in tone.Given that these photos are the only record
of this bird, I doubt it can ever be positively identified, but
I would appreciate any feedback on it.