|ring area||The Netherlands, Schiermonnikoog|
|observations||21710, of which 2305 are captures|
|ringed in||1978 to 2020|
Since 1983, Oystercatchers breeding on the saltmarsh of Schiermonnikoog and the adjacent polder have been caught and individually colour-marked. Both adult breeders and nearly fledged chicks are marked.
Observations of these marked animals allow us:
This knowledge is very important to identify the causes of the dramatic population decline of this longlived species (current record 46 years) in the Netherlands : due to an annual decrease of 5%, the population has more than halved since 1990.