L. Forró szerk.: Miscellanea Zoologica Hungarica 10. 1995 (Budapest, 1995)

Báldi, A., Zágon, A.; Bankovics, A.: Status of the avifauna in the Szigetköz riparian area: an ornithological evaluation for nature conservation

nature conservation management actions start, these species are expected to become extinct in the Szigetköz. The extinction of wetland species has already begun. The inventory in 1994 showed, that the Sedge Warbler (Acrocephalus schoenobaenus), Reed Warbler (A. scirpaceus) and the Savi's Warbler (Locustella luscinioides) were almost totally absent from the Upper Szigetköz, while they were abundant in the lower parts. Contrary, the Little Ringed Plover (Charadrius dubius), which prefer gravel shores, is more frequent in the Upper Szigetköz, than in the lower parts. A recent ornithological survey in the Slovakian part of the Danube (Országhová et al. 1994), where the watertable increased already (in spite of the tendency in the Hungarian parts), reported 100 species. This is a nested subset of our list, because they did not observe species, which were not registered by us. It will be interesting to compare the avifaunal changes in areas with decreasing and increasing watertable. The monetary value of the whole Szigetköz area was also estimated on the basis of the avifauna. The number of individuals for all protected bird species were estimated and multiplied with their monetary value. This lead to a huge number: 1.5 billion forints ( 13 million US dollars). In addition, the other taxa, and other values like ecosystem functions (e.g. soil protection, water and air clearance) and aesthetical values made the construction work totally harmful even from an economical point of view. We strongly suggest to involve conservation biological evaluations into economical estimations. Acknowledgements We are indebted to A. Griill and C. Moskát for comments on the species list and on the manuscript. The study was supported by grants from the Ministry for Environmental and Regional Policy to F. Mészáros. References Báldi, A. & Kisbenedek, T. (1994): Comparative analysis of edge effect on bird and beetle communities. Acta zool. liung. 40: 1-14. Báldi, A. & Moskát, C. (1994): Effect of the edge on the structure of bird communities in Hungarian riparian forests. In: Hagemeijer, E. J. M. & Verstrael, T. J. (eds). Bird Numbers 1992. Distribution, monitoring and ecological aspects. Poster appendix of the Proc. 12th Int. Conf. of IBCC and EOAC. - Statistics Netherlands, Voorburg/Heerlen & SOVON, Beek-Ubbergen. pp 7-10. Báldi, A., Csorba, G. & Korsós, Z. (1995): Setting priorities for tlie conservation of terrestrial vertebrates in Hungary. - Magyar Természettudományi Múzeum, Budapest. 59 pp. Décamps, H. (1993): River margins and environmental change. - Ecol. Appl. 3: 441-445. Groombridge, B. (ed.) (1993): 1994 IUCN Red List of Threatened Animals. -IUCN, Gland, Switzerland and Cambridge, U. K. 286 pp. Malanson, G. P. (1993): Riparian Landscapes. - Cambridge University Press, Cambridge. Mészáros, F. & Báldi, A. (1992): The botanical and zoological sun>ey of the planned Fertő-Hanság-Szigetköz National Park and recommendation for its zonations. I. Szigetköz, - Hungarian Natural History Museum, Budapest. (Non-published report, in Hungarian.) 325 pp. Mike, K. (1991): Paleo-hidrography and history of surface waters in Hungary. - Aqua Kiadó, Budapest. 698 pp. (In Hungarian.) Moskát, C, Báldi, A. & Waliczky, Z. (1993): Habitat selection of breeding and migrating populations of the Ictcrine Warbler (Hippolais icterina): a multivariate study. - Ecography, 16: 137-142.