Rare example of a young adult Lesser Black-backed Gull with sub-adult markings in the outer secondary S2 in both wings.
Black/Blue 3P was ringed as a pullus at Maasvlakte, Rotterdam, the Netherlands, in July 2014 and was observed during the breeding season of 2018 at the gull colony of IJmuiden Forteiland, the Netherlands, where I took these photos.
Many thanks to Roland-Jan Buijs of Buijs Eco Consult for ringing this bird and for providing the ringing details.
Gulls to the Horizon 