Images taken during a visit to the gull colony of IJmuiden Forteiland, the Netherlands, on May 6, 2019, as part of our research project.
Shown are European Herring Gulls and Lesser Black-backed Gulls.
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European Herring Gulls
A breeding adult.
Now in its 20th calendar year.
Note the lack of black on the inner web of P8 in the left wing, a feature that it shows each year.
Male YBMD with female YCPZ
Male YBRD with female YBUW
Lesser Black-backed Gulls
Fifth-calendar year with an unusual amount of black in the tail.