Images of Lesser Black-backed Gull Larus fuscus graellsii (Dutch intergrade) at various ages: as a 5th-calendar year, a 4th-calendar year and a 3rd-calendar year.
It was ringed as Green YAWC in the gull colony of IJmuiden (Forteiland), the Netherlands as a chick in July 2011.
5th calendar year
Gull colony of IJmuiden (Forteiland), the Netherlands, 15 June 2015.
Note the 2 black spots in the tail and the large amount of black in the greater primary coverts.
4th calendar year
Katwijk aan Zee, the Netherlands, 27 September 2014. It stayed here for a few days after which it was observed in Belgium at the end of October and in Spain and Portugal at the end of December.
In non-breeding plumage. Note the multi-colored bill, the dull yellow legs and the striation on the head.
3rd calendar year
Noordwijk aan Zee beach, the Netherlands, 15 June 2013.
As a typical 3rd-calendar year in June with much brown in the coverts, dull yellow legs and much black on the bill.