De jongste aantalsschattingen in internationaal perspectief Weidevogelpopulaties in Nederland

This is a review of the current knowledge on population levels of waders breeding in Dutch meadowland. It is based on a thorough and critical review of the existing literature, amplified by the unpublished information of a series of local correspondents. The international importance of The Netherlands as a breeding area is reviewed by using the data presented in the Wader Study Group publication ’Breeding waders in Europe’ (Piersma 1986). The current status of meadowland-breeding species breeding in The Netherlands is summarised in Table 1 and in Figure 2. The reasons for the recent changes in inferred population levels (Table 2) are discussed. There are both methodological artifacts and real population changes that have affected the changing estimates. The Oystercatcher. the Lapwing and the Curlew have expanded their population. The Lapwing partly is switching over to arable (maise) land, and the Curlew has recently spread to meadowland. Other species however, suffered modern agricultural practises, in particular Ruff, Snipe and to some extent the Black-tailed Godwit and Redshank. The international importance of The Netherlands for meadowland-breeding waders is summarised in Table 3. For Ruff and Snipe, which find The Netherlands on the edge of their breeding range, the country is relatively unimportant as a breeding area. However, for the remaining species The Netherlands harbours breeding populations of major international importance. The Oystercatchers breeding in The Netherlands contribute 42-45% to the total European breeding population as assessed in ’Breeding waders in Europe’ The Dutch Lapwings form 24-28% of the total European population. The majority of European Black-tailed Godwits breeds in The Netherlands: 82-85% of the birds of the limosa subspecies! Furthermore, The Netherlands harbour large populations of Curlews (5-6% of the European total) and Redshanks (16-19% of the European total). The abundance of meadow-breeding waders and the concomitant large contribution to the European breeding population gives The Netherlands a great international responsibility for these species and their breeding habitats. Since current agricultural practices often form a threat to the well-being of some of the more endangered species (e.g. Black-tailed Godwits), the Dutch government should see it as its responsability to guarantee the future of the critical breeding populations.