Common, except for some very open coastal habitats. Highest densities in extensively afforested areas, with a preference for deciduous woodland. Often benefits from nest boxes, especially in urban areas. Apart from the colonisation of newly reclaimed areas (Zuidelijk Flevoland, Lauwersmeer), hardly any changes in distribution occurred since the 1970s. A long-term increase was recorded in all habitats, interrupted only by severe winters and periods of food-shortage. Recently, the increase has levelled off, and breeding has experienced an earlier onset of laying (due to increased spring temperatures), which might cause wrong timing with respect to the availability of food resources during the nestling stage. About 500,000-600,000 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.