Abundant on the higher, sandy soils, but habitat-specific and local differences in densities here are hardly visible in the map. In the lower parts of the country, the distribution is strongly associated with the more wooded areas, including estates in the inner dunes and urban habitat. Strong range expansion and population increase since the 1970s demonstrates the species’ willingness to colonise new (more open) habitats. Besides, it has benefited in woodland from atmospheric deposition (increased coverage of bramble and other shrubs, offering excellent nesting opportunities). About 270,000-320,000 bp in 1998-2000.
Hustings, F., Majoor, F.