Voorkomen en terreinkeus van Slechtvalken Falco peregrinus in het Noordelijke Deltagebied

In this paper the author has brought together winterobservations of Peregrine Falcon Falco peregrinus in the northern part of the Delta, Southwest Netherlands. The study covers 30 years, from winter 1965-1966 untill 1994-1995. Numbers of Peregrine increased remarkable after the pesticid period, from none to one every winter at the end of the sixties till an average of 1,2 Peregrines during each excursion in 1994-1995. The author estimates that nowadays 9-13 Peregrine Falcons winter in the northern part of the Delta. Peregrines prefer staying in spatial areas with concentrations of wildfowl and waders. In the northern part of the Delta ten areas exist with regular wintering Peregrines. The birds have their favourite observation-points. If there are powerlines over favourite peregrine haunts, pylons as observation-posts have a preference. No standard investigation of prey has been carried out. In two areas Peregrine kills of Mallard Anas plathyrynchos Teal Anas crecca, Eurasian Wigeon Anas penelo-pe. Kestrel Falco tinnunculus, Lapwing Vanellus vanellus, European Golden Plover Pluvlalis apricaria. Wood Pigeon Columba palumbus and domestic dove were found. Stooping of Peregrines was observed a.o. on Bittern Botaurus stellaris. Whitefronted Goose Anser albitrons and Barnacle Goose Branta leucopsis. Both springobservations of displaying pairs as well as summering Peregrine Falcons increase. In the nearby future breeding Peregrines in the Delta are not out of question.