Arrabona - Múzeumi közlemények 6. (Győr, 1964)

Sey O.: Adatok a Hanság gerinces állatvilágának ismeretéhez

DATA TO THE KNOWLEDGE OF THE VERTEBRATE ÍVIMTMALS ÜÍ THJE HANSÁG The Hanság is an area in the Little Hungarian Plain, having a special character. Owing to the development of its geological history and to the peculiarities ot its vegetation, it used to have a rich and variegated fauna. In course of the drainage operation begun in the last century and continued in our days, the Hanság ceased to be a moorland. The fact that the waters supplying the one-time fen have been forced into channels, has brought a radical change in the ancestral fauna. Most of the species bound to the water either perished or settled elsewhere, so to-day we meet only those species which were able to acclimatize to changed conditions. The fish fauna of the Hanság is a rich one. We succeeded in proving more than the half of our Hungarian fishes (33 species). The large number of fishes may be explained by the variegated biotopic conditions of the water system; beside the channels of slow running, nay almost stagnant, there are also waters of middle and live flow. A rare species of fish, the Telestes Agassizi Heck, is derived from the Repce. Fishes play an important part in the chain of alimentation. Amphibia and reptiles are represented in a small number in the Hanság. With a single exception, each species is widely extended and corresponds to the geographical situation of the area. The most special member of its herpetofauna is the fallow viper (Vipera ursinii Rákosiensis). Most of the vertabrate fauna of the Hanság is made up of birds. One third of the Hungarian avifauna is found here. As related to the large area, there are rather few nesting and rather numerous passing ones. Owing to the lack of stagnant waters the fauna attached to these is almost entirely missing. As there are no old, hollow trees, breeding is impossible for numerous species. As rare bird species we mention the black stork (Ciconia nigra) and the froghunting eagle (Aquila pomarina). The mammal fauna of the Hanság has no especially characteristic species. Owing to the spreading of civilization, the Hanság shows hardly any characteristic vertebrate species in our days, gradually becoming a part of the Little Hungarian Plain from a zoological point of view too. ! i i O. Sey 384