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.
The study of foraging behaviour of 20 forest bird species was conducted during two different phenophases of a vegetation period in the West Carpathians oak-dominated natural forests. Using a standard and a modified a priori approaches, seven foraging guilds were distinguished, whereas only five significantly different guilds were clustered by a a posteriori approach. Four common guilds for all three approaches were quantitatively compared. The methods differed especially in the classification of foraging generalists. Differences in guild densities between a priori and a posteriori approaches emerged in both, the pre-foliage and the foliage periods, chiefly in the guilds of insectivores on ground surface (47.3–89.6%) and insectivores on buds/leaves and twigs (15.0–45.9%). The modified a priori method provided moderate densities of separate guilds. The modified a priori method with more detailed density calculation is recommended for the quantitative guild structure comparisons of different bird assemblages. The method takes into consideration proportional use of foraging substrates in combination with food type.