358 Folia Zool. – 57(4): 358–372 (2008) Bats in a Carpathian beech-oak forest (Central Europe): habitat use, foraging assemblages and activity patterns Martin CeľuCh 1,2 and Rudolf KRopil 2 1 Slovak Bat Conservation Society, P.O. Box 10A, 949 01 Nitra 1, Slovak Republic; e-mail: mato@netopiere.sk 2 Technical University in Zvolen, Faculty of Forestry, T. G. Masaryka 24, 960 53 Zvolen, Slovak Republic; e-mail: kropil@vsld.tuzvo.sk Received 24 January 2007; Accepted 9 July 2008 A b s t r a c t . Carpathian forests represent unique and well-preserved ecosystems in relatively intensively managed forests of europe. habitat use, foraging assemblages and activity patterns of a bat community were investigated in semi-natural beech-oak forest by monitoring echolocation calls and mist-netting at three localities during the summers of 2003 and 2004. Six different forest habitat types were studied: oak forest, beech forest, stream, road, forest edge and open area within the forest. Bats were detected in all habitats. Sixteen species were found. habitats were used differently by the individual species. The highest species diversity was observed in the forest interior. The first peak of flight activity was after sunset which then declined and was relatively even through the night until the second peak before sunrise, which was recorded in the forest interior, open area and on the road. The highest flight activity was recorded at the forest edge, forest stream and in open area. Recorded activity was 3× lower in the oak forest interior compared to the forest edge, but if the extent of the forests is considered, forest interior is the most important foraging habitat. Consequently future forest management should consider the needs of this endangered group of animals. Key words: Chiroptera, detector, beech, oak, feeding sites Introduction Foraging grounds, together with roosts are the two main factors that enable the survival of bats (Barclay & Brigham 1996, Meschede & heller 2000, l a c k i & B a k e r 2003). The majority of central European bat species are partially or entirely confined to forest ecosystems (W a l s h & harris 1996, Z a h n & K r ü g e r - B a r v e l s 1996, Meschede & heller 2000, R u s s o & J o n e s 2003). Although understanding of suitable foraging habitats is essential for the protection of these endangered animals, knowledge of the preferred foraging grounds in forests is inadequate (Z a h n & K r ü g e r - B a r v e l s 1996, J u n g et al. 1999, p a t r i q u i n & B a r c l a y 2003). Recently, there has been intensive development of “forest bats” research, mainly in North America and Western Europe (B a r c l a y & B r i g h a m 1996, M e s c h e d e & heller 2000). Radio-telemetry and ultra-sound detectors are used to a large extent, although the relevance of data obtained by ultra-sound detectors is currently being reviewed (J e n s e n & M i l l e r 1999, S c h e r w i n et al. 2000, G a n n o n et al. 2003, M i l l e r et al. 2003). There are still plenty of unanswered and controversial questions about the choice and preference of the foraging habitats of bats (W a l s h & harris 1996, F e n t o n 2003, M i l l e r et al. 2003). Most acoustic studies in the forests have revealed that higher flight activity occurred at the forest edges and in open habitats. These habitats are considered as preferred (W a l s h & M a y l e 1991, C r a m p t o n & B a r c l a y 1996, G r i n d a l 1996, K u s c h et al.