© A. R. Dean

Herring Gulls in their third and fourth calendar years can be difficult to age as there is great variability and overlap in plumage characters. The bright, adult-like bare parts suggest 4cy (3S) but prominent brown markings in the tertials and coverts indicate 3cy (second-summer moulting into third-winter) while the limited extent of white in the primaries also accords with this age. Compare it with the photo of a more straight-forward 3cy (2S/3W) photographed in August and a putative 4cy (third-winter) individual - the latter has less advanced bare parts but more advanced plumage.