|ring area||The Netherlands, Wieringen|
|observations||13511, of which 1006 are captures|
|ringed in||2000 to 2023|
The project is a Retrapping Adults for Survival project at the former island of Wieringen on the most northern point of Noord-Holland. Since 2000 several hundreds of birds are ringed. The survival rate differs per year, but is normally between 75 and 95% for adults. Most birds are seen in the breeding area, but there are also some interesting ring readings along the flyway between Netherlands and Africa.
All birds have a wihite ring on the tibia (with a letter followed bij 2 digits). Some birds also have a green flag on the other tibia.