Ábrahám Levente: Biomonitoring a Dráva folyó magyarországi szakasza mentén 2000-2004 - Natura Somogyiensis 7. (Kaposvár, 2005)

Dombi, Imre: Bat monitoring along the Drava River (Mammalia: Chiroptera) - Denevér-monitoring a Dráva mentén (Mammalia: Chiroptera)

Natura Somogyiensis 7 143-156 Kaposvár, 2005 Bat monitoring along the Drava River (Mammalia: Chiroptera) DOMBI IMRE Nature Conservation Foundation of Tolna County, H-7100 Szekszárd, Szent István tér 10., Hungary, e-mail: imreka@freemail.hu DOMBI I: Bat monitoring along the Drava River (Mammalia: Chiroptera). Abstract: In the Drava monitoring project bat monitoring has been carried out along the Drava between Ortilos and Babócsa since 2000 with the methods below, three times a year: capture with net and ringing, sampling with bat-detector along a path, point counting in the case of Daubenton'

s bat and pond bat, survey of buildingdwelling colonies. Four sampling areas were chosen: Ortilos - floodplain of Drava, Gyékényes - Lankóci forest, Vízvár - floodplain of Drava and village, Babócsa - Mérus forest and backwater of Drava to carry out monitoring on. 17 species of bats were indicated in the five years of research, three of them are endangered species Barbastelle bat {Barbastella barbastellus), Bechstein's bat {Myotis bechsteini) and the pond bat {Myotis dasycnemé). The region is quite abundant in species of which most are vulnarable not only in Hungary but also across Europe. All this indicates the natural status of the sampling areas and marks the importance of the floodplain along Drava in the conservation of the species concerned. Key words: bat, monitoring, bat-detector, Drava, habitat Introduction Danube-Drava National Park Management started the natural monitoring of the upper part of River Drava in Hungary in 2000 with the purpose of monitoring the effects of the hydroelectric power plant panned at Novo Virje, Croatia and prognosticating its probable impact based on records of original state of the area. As a part of this wide-range project, bat monitoring is performed by our Foundation. Samples are taken following the standard monitoring rules of sampling in the same sample area, at the same time, administering the same methods to be able to do any comparisons among results. Four sample areas were chosen: Ortilos floodplain, Gyékényes - Lankóci forest, Vízvár - Drava bank and settlement, Babócsa - Mérus forest and the backwater of Drava. Material and methods Sample areas More features had to be taken into account simultaneously while choosing the appropriate sample areas. Here they follow: - impact of Drava on the bat colony in the sample area present - representative sampling in the same sample areas even during the long period - ten years - of monitoring with the possible least effect of the inevitably occurring natural changes.