Nowadays a regular breeding bird in most wetlands in the lower parts of the country and many ponds, fens and lakes on the pleistocene soils. Most occupied atlas squares hold less than 10 bp. Strongholds with over 100 bp were recorded in 15 atlas squares scattered over the country. During the 20th century a spectacular increase occurred, from almost extinct to 100-150 bp in 1977, and 8000-9000 bp in 1998-2000. The exponential increase in the past decades is in line with similar developments elsewhere in the breeding range.
- 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.