Bijdrage van Friesland aan de vervolging van broedende roofvogels in Nederland in 2000-09

Raptor persecution in The Netherlands is widespread, but with distinct geographical variations. This paper puts the Frisian contribution to raptor persecution in a countrywide perspective. To that end, all nest records for raptors, as collated and analysed by the Dutch Raptor Group, were reanalysed for the period 2000-09. The proportion of nests disturbed in The Netherlands by human intervention varied from 5.26% in Marsh Harriers (in N=1958 nests), to 4.20% in Goshawks (N=5448), 3.73% in Buzzards (N=15369), 0.95% in Hen Harriers (N=210), 0.65% in Honey Buzzards (N=465), 0.57% in Sparrowhawks (N=4384), 0.44% in Hobbies (N=1148) and 0.41% in Kestrels (N=7844). Of all 972 disturbed nests, 57% were registered in the province of Friesland alone, a disproportionate number given the fact that Friesland only covers 13% of the countries’ surface area. Of the nests recorded in each province, by far the highest proportion of deliberately disturbed nests were found in Friesland, i.e. 8.5 times higher than in the rest of The Netherlands for Buzzard, 4.2 times higher for Sparrowhawk, 3.2 times higher for Goshawk and 2.7 times higher for Marsh Harrier. Only for Kestrel, the level of persecution in Friesland did not differ from the rest of the country. Moreover, whereas the annual proportion of deliberate nest disturbances remained more or less constant in the rest of the country, a significant increase was recorded for Friesland. Preliminary data for 2010 indicate that this trend has persisted.