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

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

Avifauna of the Kis-Balaton Reservoir area 25 In the first years my investigations were incorporated into the scientific program of the Eötvös Lóránd University, headed by G. GERE. Later, as I started to work in the Hungarian Natural History Museum, I joined the museum's Balaton ecological research program. RESULTS AND DISCUSSION Different habitats: wet meadows (Alopecuretum pratensis, etc.), marshy forests (Alnetum glutinosea, Salicetum, etc.), and some agricultural fields of the villages Zalavár, Zalaszabar, Nagyrada, Garabonc, and Balatonmagyaród had suffered dramatic changes due to the inundation in 1984. These habitat modifications caused dramatic changes in the populations of the bird communities. No bird species have disappeared from the area due to the habitat changes because their original habitat remained as fragments along the edges of the lake and in the islands. However, the population size of different species declined in different rates and quantities. I have found eighty-four breeding bird species in the flooded area and in intact habitat fragments in the area during the first five years of the reservoir (Table 1 and 3). We can divide the present-day avifauna into two groups according to their origin as follows. 1. Former breeding species of the area (56). (Table 1) 2. New settlers of the area after it was flooded (28) (Table 3). Populations of the 1. group's species show two different tendencies: a. ) There are fourty-seven species whose breeding habitats have changed in a negative way. Their populations have declined but have survived and presently they breed in the intact habitat fragments remaining along the edge of the area, and on the islands of the lake. b. ) There are nine species whose breeding habitats have changed in a positive way. Their populations increased after the inundation (Table 2). Table 1. The list of the former breeding species of the Kis-Balaton Reservoir area (56 species) Parus major Parus caeruleus Remiz pendulinus Sitta europea Certhia brachydactyla Troglodytes troglodytes Turd us philomelos Turdus merula Sœdcola torquata Saxicola rubetra Luscinia megarhynchos Erithacus nubecula Locustella fluviatilis Acrocephalus schoenobaenus Sylvia atricapilla Non-Passeres Podiceps nificollis Anas platyrhynchos Anas querquedula Anas acuta Anas clypeata Buteo buteo Falco tinnunculus Perdix perdix Phasianus colchicus Rallus aquaticus Porzana porzana Gallinula chloropus Vanellus vanellus