L. Forró - É. Murai szerk.: Miscellanea Zoologica Hungarica 6. 1991 (Budapest, 1991)

Bankovics, A.: Avifauna changes of the Kis-Balaton Reservoir area

MISCELLANEA ZOOLOGICA HUNGARICA Tbmus 6. 1991. p. 23-30 Avifauna changes of the Kis-Balaton Reservoir area by A. BANKOVTCS (Received June 30,1991) Abstract: The avifauna of the artificial water-reservoir in the Kis-Balaton Landscape Protection Area was studied between 1984 and 1988. The study area includes a newly made lake of 2500 hectares and its surrounding marshes, meadows, forests, and bushy vegetation. During the first five years of the new lake's surroundings, eighty-four breeding bird species were recorded. Among the eighty-four species, there were fifty-six, which had been breeding in the area before it became flooded in 1984. The other twenty-eight species were pioneers or settlers in the area after the lake had been made. The nesting of the Red-crested Pochard (Netta rufina) here is the first record in Hungary. Keywords: Reservoir, Kis-Balaton Landscape Protection Area, habitat change, avifauna INTRODUCTION In the early 80s there was a great investment in order to reduce the eutrophication of Lake Balaton. One of these projects was aimed at recreating the former role of the marshy Kis-Balaton, to filter the polluted water of the River Zala. For this purpose they built an artificial lake of 2500 hectares in the basin between the villages Zalavár, Zalaszabar, Garabonc, and Balatonmagyaród. Today the lake is divided into ten different regions. Most of them are connected with one another. The water regions are numbered (I-X) and named mostly after the villages (Fig. 1). In 1988 the area became protected, and since then it is part of the Kis-Balaton Landscape Protection Area. In the present paper, I wish to give a preliminary summary of the avifauna changes of the area (a detailed elaboration will be published elsewhere), and in the second part, I will give short descriptions of the population trends for some species of the orders Podicipediformes and Anseriformes, which are of great conservation importance in the area. METHOD I started to study the whole avifauna of the area in 1984 when the area was first flooded. The main concern was learning what species would adapt to life in the new artificial lake. For this purpose I did most of my field work during the breeding season. Besides my field data, I was provided with useful information and population data by the E. FUTÓ, the nature conservation guard of the protected area.