|ring area||The Netherlands, SW Delta|
|observations||269, of which 6 are captures|
|ringed in||2010 to 2020|
Every year, several hundred Oystercatchers are individually colour-marked in the Netherlands and Schleswig-Holstein. Both adult breeders and nearly fledged chicks are marked. Some of these animals feed in places, like oyster beds, where their colour rings are subject to heavy wear and become quickly unreadable. If possible, such animals are fitted with an engraved ring on the tibia, where it is more difficult to read, but will not suffer from heavy wear.
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.