|ring area||The Netherlands|
|observations||144446, of which 8971 are captures|
|ringed in||1997 to 2021|
Throughout the Netherlands, thousands of Black-headed Gulls ringed with white four-character-rings with the letter E as first character. These rings are used for nestlings as well as breeding and wintering birds. These rings have four characters of which at least one is a digit. The letters B, D, G, I, O and Q are not used.