Highest densities in rural areas with a high proportion of grassland. Densities in urban areas may locally be high as well, but extensive woodland and open arable areas are more thinly populated as feeding opportunities (i.e. grassland) are low here. Except for the colonisation of the reclaimed polder Zuidelijk Flevoland, no changes in distribution could be detected. However, numbers in woodland experienced marked declines since the 1970s. Elsewhere, population trends fluctuate (urban areas, farmland). It is hypothesized that the species is susceptible for changes in agricultural practices, such as drainage and conversion of grassland into arable fields. About 500,000-900,000 bp in 1998-2000.
Bron
Auteur(s)
Dijk, A. J. van
Publicatie
- 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.