This Black-headed Gull was marked in Sweden, (VÄSTERBOTTEN, NORRMJÖLE, INNER ÅHÄLLAN0, 63º 39´N, 20º 07´E) as nestling on June 30, 2014. This is 1570 km NE of Leiden. It was present in Leiden again on November 28, 2015. On December 6, 2015 the color ring W[E2YZ] was added in Leiden.