The coastal breeding distribution is only interrupted along the mainland coast due to permanent tourist pressure. The Wadden Sea area (160-180 bp in 1998-2000) and the Delta (150-170) hold the majority of the population, but densities rarely exceed 10 bp/atlas square. Since 1973-77, inland breeding became uncommon, especially after cultivation of Flevoland. In the core areas, numbers remained stable (Wadden Sea) or fluctuated with the availability of temporary habitat during large construction works (Delta). The national population peaked around 1980 (400-650 bp) and has slightly decreased since (430-470 bp in 1998-2000).
- SOVON Vogelonderzoek Nederland 2002. Atlas van de Nederlandse broedvogels 1998-2000. Nederlandse Fauna 5: 1-584. Nationaal Natuurhistorisch Museum Naturalis, KNNV Uitgeverij & European Invertebrate Survey-Nederland, Leiden.