Estók P. és Görföl T. (2009): Erdőlakó denevér együttesek kutatása, különös tekintettel a Nyctalus lasiopterusra - egy 2009-es EUROBATS projekt előzetes eredményei. VII. Magyar Denevérvédelmi Konferencia, Felsőtárkány, 2009. október 16-18., pp. 53-60.

Erdőlakó denevér együttesek kutatása, különös tekintettel a Nyctalus lasiopterusra - egy 2009-es EUROBATS projekt előzetes eredményei
Estók Péter - Görföl Tamás
Bükki Emlőstani Kutatócsoport Egyesület

The research of forest-dweller bat ensembles with special respect to Nyctalus lasiopterus - preliminary results of a EUROBATS project conducted in 2009

The life of forest-dweller bat species is poorly known. Information on their roost preferences and habitat use are crucial to protect them. The major threat to these species is the intensive sylviculture which destructs their roosts and foraging places as well. Pairs of sample sites (forest-clearcut) were selected to conduct a bat detector survey to get information about the differences of the clearcuts and the forested habitats in the Bükk Mountains. To evaluate the data the identified bats (on species or genus level) were grouped into two categories based on their feeding strategy and habitat use which links them to habitats with "closed" or "opened" character: (1) O/E (Opened/Edge) species group, these bats typically foreage in open spaces or at edges, they mainly use fast hawking foraging strategy, showing rapid flying (or slower in the case of Pipistrellus spp.): Nyctalus noctula, N. leisleri, Pipistrellus pipistrellus, Miniopterus schreibersii; (2) C/E (Closed/Edge) species group: these bats mainly forage in closed environments like in forests, or in edges, their foraging strategies are mainly gleaning and slow hawking: Myosotis spp., Barbastella barbastellus, Plecotus spp., Rhinolophus spp. Samplings were conducted in two series, one in mid summer and one in early autumn. In the case of the first sample series totally 56 bat call sequences were found between the 640 recordings. The frequency of the C/E species group was significantly higher if forested sampling points than in the clearcuts, while the frequency of the O/E species group was significantly higher in the case of clearcut sampling points than in forested habitats. From the 7077 recordings of the second sample series, 471 recordings included bat calls. 446 bat calls were classified based on the two species group, 25 bat recordings were not classified and were excluded from data analysis. Not any significant differences were found in the frequency of the C/E and the O/E species groups between the forested sampling points and the clearcut habitats. Further sample series are needed to make exact comparisons.
Regarding the interesting and rare Nyctalus lasiopterus we conducted an intensive detector survey in order to find new populations throughout the country. One new locality of N. lasiopterus was found in the Zemplén Mountains where the species was not observed since 2000. At the most significant known location of the Hungarian population four specimens were tagged with radio transmitters. Four new roosts were located, high numbers of social and emerging calls of the species were recorded for later analysis. All the roosts were in beech trees. 52 emerging specimens were counted at one roost, which is the biggest sized roost in Hungary till now.