Voorlopige resultaten van de strandtellingen in het seizoen 1984/1985

During last winter season three surveys of the Dutch North Sea coast (figure 1) have been carried out in order to count shorebirds and the coastal waterfowl. Table 1 shows the number of kilometers surveyed on each occasion. This paper presents the preliminary results (tables 2,3 and 4). Apart from Eiders no important numbers of waterfowl wre observed and even these were far less numerous than on the nearby Wadden Sea (Swennen 1976). The most important species of waders observed were Oystercatcher. Sanderling and Dunlin. Of the first two species the numbers per km are presented for each survey and each area in the figures 2a and 2b. In January the Oystercatchers seem to have left the North Sea coast of the Wadden area, presumably because of the severe winter. Sanderlings wintered in considerable numbers in the Wadden area, but had left in April. The figures 3a, b, c and d show the numbers per km of respectively Black-headed, Common, Lesser Black-backed and Herring Gull. All four of these show low numbers in April, probably reflecting the occupying of territory sites in the breeding area. Furthermore migration within Holland is suggested by the data of Black-headed Gull, while Common Gulls seem to be more numerous in winter than in autumn. Lesser Black-backed Gulls disappear altogether in winter and Herring Gull remain more or less constant during autumn and winter.