Absent only in almost treeless areas. Densities are highest in woodland, but differences here between optimal (well-structured deciduous forests) and sub-optimal habitats (coniferous forests on poor sandy soils) are not adequately shown in the relative abundance map because of methodological problems. A range expansion since the 1970s into the lower and more open parts of the west and north of the country coincides with an increase of wooded areas here. Elsewhere, a slow but persistent population increase was recorded in all habitats. Some 350,000-450,000 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.