Breeding is nowadays almost exclusively restricted to farmland reserves in the northwest (Noord-Holland) and northeast (Friesland) of the country. Numbers per square are very low (generally less than 4 hens) and show marked annual fluctuations, perhaps partly related to the numbers of spring migrants. A withdrawal from all peripheral sites since the 1970s was caused by the industrialisation of farming practices. Equally dramatic decreases in numbers have been recorded throughout the second half of the 20th century: 6000 hens in the 1950s, 1500 in 1978 and 100-140 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.