Bencsik János szerk.: Hajdúsági Múzeum Évkönyve 2. (Hajdúböszörmény, 1975)

Avi-coenological Examinations in the Hortobágy Region. The Meggyes Forest

István Fintha AVI-COENOLOGICAL EXAMINATIONS IN THE HORTOBÁGY REGION. THE MEGGYES FOREST. The present paper deals with the composition and the quantitative conditions of the avifauna in the Meggyes Forest in the Hortobágy Region. The oldest growing stock of the young forest is an Robinia forest (5,25 hectares) and a poplar forest (1,75 hectares), both approximately 35 years old. Covering the majority of the area (24,50 hectares) the oaks have been planted in the early fifties. The 35 hectares of wooded land are surrounded by a „puszta" (steppe) with almost no wooded vegetation, including agricultural areas divided by some meadows and moors. There are also some major fish-ponds nearby providing rich food for most of the nesting forest species. 46,59 p. c. (88 species) of the bird species observed in the forest in the years 1969—1972 were migrating, straying or merely staying for the winter, while 53,41 p. c. were nesting. The overwhelming majority of the latter take their food outside the forest (1398 couples, 94,14 p. c.), the rest (87 couples, 5,86 p. c.) subsists on the forest. The former belong to 12 species only, the latter to 34. Most nesting birds belong to species gathering in colonies (Corvus frugilegus, 64,98 p. c. ; Nycticorax nycticorax, 24,58 p. c.) and to associated species. The distribution of the nesting species according to other viewpoints (nest level, way of life etc.) is presented in tables of the descriptive part. The ornithological importance of the Meggyes Forest (and many similar biotops of the Hungarian Lowlands) can be summarized as follows: 1. It gathers the nesting birds of the surrounding treeless plains. The high density of its bird population results also from the large colonies of the associated species. 2. The small puszta forest is also most favourable for the settlement and nesting of birds which play an important role in controling the parasites of fields near-by. Observed in the small wooded biotop, the high number of nests does not mean that every nesting species subsists on the forest, for most of them actually take their food from the neighbouring cultivated areas. 3. On account of its insular character it provides an adequate resting place and food resource for the migratory birds. 4. Finally, it provides the last possibility of survival for the species which have lost their original conditions of existence and represent a valuable asset in regard to nature conservation. It thus saves those species which are on the verge of extinction but whose subsistance is still soundly based on the rich food resources of the cultivated areas, fish-ponds etc. near-by. As a consequence it is desirable to pay more attention to the thorough examination of the avifauna of these wooded biotops, with special regard to quantitative conditions besides the structural investigation of the avifauna. 2* 19