**Acknowledgements**

These data show that Koyunbaba Cave is an important nursery roost for large populations of many bat species in the summer, as it has appropriate microclimatic conditions, large roosts,

**Figure 10.** The breeding/nursing colonies of the bats in Koyunbaba Cave: a mixed colony of species *M. schreibersii, M. myotis, M. blythii*, and *M. capaccinii* (a), a nursery colony of Rhinolophidae family: grey(light)-colored bats are juveniles,

Turkish Thrace, located in the north-west of Turkey, served as a bridge between the Balkans, Anatolia, and Mediterranean. Thrace is one of the major biogeographic zones in Turkey and, due to its karst formation, there are many caves with different characteristics in the region. Due to these features, Thrace region, which has been an important glacial refuge for bats in the past, still provides a pretty opportunity to be hosted particularly for obligatory cave-

Roost selection is essential for bats that spend more than half of their lives in roost [13]. Caves may serve as one of the most adequate roosting sites for bats because of the relatively stable microclimatic characteristics. Dupnisa Cave System and Koyunbaba Cave are the most important underground habitats for bat populations in southeastern Europe [34–38]. The hosting of large populations (56,600 hibernating bats and 11,000 breeding/nursing bats) of many bat species (18 species) is an indicator that Dupnisa Cave System is the most important shelter in the region. In addition to this, Koyunbaba Cave, which is used by a large breeding/nursing population (29,500) consisting of 11 bat species, is the most important summer roost in the region. Some bat species are listed as Near Threatened in the IUCN Red List, because of their declining populations in most of the European countries [43]. However, the populations of these species in Balkans and Turkey are stable [43], because Turkish Thrace provides many appropriate shelters to use by bats such as Dupnisa Cave System and Koyunbaba Cave.

Many species have very specific microclimatic requirements for roosts [18]. Microclimatic requirements of bats show seasonal variations according to their annual life cycle. Microclimatic conditions of roost and microclimatic requirements of species may contribute to patterns of association of bats [18, 23, 44]. Therefore, cave availability for bats is increased by providing alternative microclimatic conditions according to seasons. Most of the caves in

dwelling bats. Turkish Thrace hosts large populations of many bat species [32–38].

and entrances.

92 Cave Investigation

brown(dark)-colored bats are adults (b).

**4. Conclusion**

This chapter is produced from the following theses of the author. Master thesis (2004): Dupnisa Mağara Sistemi Yarasaları (Mammalia: Chiroptera). Doctoral thesis (2009): Koyunbaba Mağarası (Kırklareli-Türkiye) Yarasa Faunasının Mevsimsel Populasyon Değişimleri ve Tünek Seçimi.
