Conservation of Miniopterus schreibersii and Rhinolophus euryale nursery in the Veternica Cave

Miniopterus schreibersii and Rhinolophus euryale are considered as priority species for autecological studies according to UNEP/Eurobats. In Croatia all bat species are legally protected. In the Croatian Red List (2004) M. schreibersii is in the EN category and R. euryale in the VU category. Research on both species started in 2003 in the Veternica Cave near the town of Zagreb, the capital of Croatia. The nursery of both species with ca 500 individuals uses the unprotected, warmest part of the cave. Although the cave is under the authority of Medvednica Nature Park, the bats are often disturbed since it is very close to the capital and guided tour is encouraged. The path leading to one of the popular tourist spots passes by the cave and bats may easily be disturbed. A data logger measuring the temperature and relative humidity every 5 minutes is located in the part used by bats. The bats usually start to use the cave in June and depending on the weather they may stay there until late October. In the year 2003 no young were recorded in the cave, but there were young in the following year. Possible reasons for this may include extensive disturbance by visitors. In this work we present data on current status of both species in Croatia, microclimate measurements, wing design of traced individuals and a proposal for using grills that would restrict disturbance of bats by visitors for the protection of that part of the cave.