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

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

pairs in 1985 and fifty pairs in the years 1986 and 1987. The population was estimated to have sixty breeding pairs in 1988 (Table 4). Red-crested Pochard (Netta rufina) It was a rare passage migrant in Hungary until the 1960s. Since then its occurrences become more frequent (BANKOVICS 1968, 1986,1987). I surmise that it was the consequence of the growing breeding population of the Lednice area in Czechoslovakia. From the Lednice area it began to spread in the direction of Lake Fertő, where it has also settled as a breeding species in 1986 (KÁRPÁTI pers. comm.). In the Kis-Balaton Reservoir a few breeding pairs settled since the first year (1985), and since then they breed continuosly every year (Table 4). Tufted Duck (Aythya fuligukt) This species used to be very rare and an irregular breeding bird in Hungary until the Kis-Balaton Reservoir was established. Its first breeding case in Hungary was reported in 1965 (NAGY 1967). Until 1984 their breeding cases were recorded in different sites. In the Kis-Balaton Reservoir they became a rather numerous species, and they are the dominant one among the diving ducks. In the first year (1985) fortysix breeding pairs were counted. The population number increased three-times in the next year (1986), but showed a slight decrease following that (Table 4). ACKNOWLEDGEMENTS I wish to express my gratitude to the nature conservation guards of the KisBalaton Landscape Protection Area, to Elemér FUTÓ, József LAKATOS and István LÁZÁR for their hospitality and helping my fieldwork. REFERENCES ARADI, CS. & G. KOVÁCS (1982): The Grey-leg Goose in Hungary. - Aquila, 89: 77-88. BANKOVICS, A (1968): Red-crested Pochards on the pond of Péteri. - Aquila, 75:296. BANKOVICS, A (1986): A Balaton átvonuló és telelő vízimadarainak állománybecslése [Estimate of the Waterfowl population passing across Lake Balaton]. -Aquila, 92: 55-65. BANKOVICS, A. (1987): Red-crested Pochard (Netta rufina) on lake Csaj. Aquila, 93-94: 309. BANKOVICS, A (1988): The Modifying effect of the new artificial Water-Reservoir at Kis-Balaton on the Hungarian Avifauna. - Abstracts: 18th Cong. Hung. Biol. Soc. 1988:15. FUTÓ, E. (1990): Recent nesting bird species at the Kis-Balaton Water Reservoir, Section I. -Aquila, 96-97: 154.. KEVE, A. (1976): Adatok a Kis-Balaton madárvilágához [Data to the avifauna of the Kis-Balaton]. -Aquila, 82: 49-79.