I stumbled on a couple of GBBGs (2nd and 4th summer type), 1 LBBG (1st summer) and, surprisingly, only 4 juvenile Herrings from some 275 individuals.
The single mirror on p10 and absence of a p9 mirror suggests a younger bird. The brownish greater primary coverts also point away from a definitive adult.
|4th Summer Type GBBG.|
My only Lesser Black-backed Gull, a species that I thought I'd see more of on the west-central Michigan lakefront:
P1-P7 fully grown, P8 half grown, P9 dropped, P10 old. S1-S2 renewed, as well as most inner/mid secondaries. 03 August 2016.
|Another 1st summer type with S1-S3, P1-P8 fully grown as well as all rectrices. The bi-colored bill is a much more expected look.|