ageing Little Gulls

having had another session photographing Little Gulls at Hornsea 12.9 it struck me that many of the first-summer birds had moulted most of their flight feathers into adult like plumage with no blackish sub-terminal marks or outer webs---I took a series of photos which I hope demonstrate that this can be a feature of large numbers of Little Gulls rather than just the odd bird as I noted at least 20 such individuals this afternoon in close views---most had contrasting paler grey underwing coverts but some even had these as black as adults see post below---In the Gulls guide the only description of second winter Little Gull includes black sub-terminal marks or outer webs on primaries 5/6-10
in this post from the top second-winter with obvious black sub-terminal spots on outer prims and pale underwing coverts and paler grey underside to flight feathers than adult; upper right bird first-summer moulting to second winter p10 old all the others with adult type pattern, some retained juv tail feathers; second-winter with black subterminal mark on one primary and two still growing; possible second-summer moulting to adult winter but outermost primary appears more like a juvenile feather?; second-winter with dark subterminal marks on outer three primaries------