Highest densities are recorded on arable land in the lowlands. The gradual imposed ban on releases of captive-bred birds has resulted in deserted areas (e.g. Veluwe) or declining populations in both newly reclaimed polders (Flevoland, population thriving in 1970s and 1980s) and extensive woodland, accelerated by increased predation of Northern Goshawk and red fox. Monitoring results point at ongoing declines, although on a local scale numbers may still be inflated by illegal releases. At least 50,000-60,000 males 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.