**3. Results**

#### **3.1. Microclimate of Dunisa Cave System**

Dupnisa Cave System, which has four entrances and three parts with different characteristics, provides seasonally different microclimatic conditions in the different parts (**Table 1**). Paksuz et al. [36] stated that the temperature varies between the different parts of the cave system, as well as by season. While the winter temperature ranges from −1 to 12°C in Sulu Cave, 8 to 14°C in Kuru Cave, and 10 to 14°C in Kız Cave, the summer temperature varies from 9 to 14°C in Sulu Cave, 13 to 22°C in Kuru Cave, and 13 to 18°C in Kız Cave. In winter, the mean temperature of Sulu Cave is significantly lower than from Kuru Cave and Kız Cave. During summer, the mean temperature in Kız Cave and Kuru Cave is significantly higher than in Sulu Cave. In Sulu Cave, the average temperature in winter is 7.4°C, in summer 10.7°C; in Kuru Cave in winter 11.4°C, in summer 16.3°C; in Kız Cave in winter 11.9°C, in summer 15.9°C. Humidity also varies depending on the caves and the seasons. The humidity in Dupnisa Cave System varies from 57 to 100%. The mean humidity in winter is similar and higher in Sulu Cave and Kız Cave, while it is lower in Kuru Cave. During summer, the humidity is similar in all three caves.

#### **3.2. Bats of Dupnisa Cave System**

**Figure 5.** The three entrances of Koyunbaba Cave: the main entrance (a), the second entrance (b), and the third entrance (c).

Cave is closed to visitors, but this area of the cave is used by local people as an animal shelter during the summer. The second and third entrances of the cave are vertical. Because they are quite dangerous, these entrances cannot be used by local people (**Figure 5**). The cave is located in a relatively flat area consisting of farmland and pastures. This area is outside the Strandja Forest tree line. There are important water resources (Teke stream and Kayalı dam) around the cave.

**Figure 4.** Koyunbaba Cave: the location of the seasonal roosts used by the bats, the three entrances of the cave. Adapted

from Ref. [31].

86 Cave Investigation

Up to now, 17 species of bats have been recorded in Dupnisa Cave System, which is the most studied cave in Turkey in terms of bats. Five of these species belong to Rhinolophidae family (*Rhinolophus ferrumequinum, R. hipposideros, R. euryale, R. mehelyi*, and *R. blasii*) and 12 of them belong to Vespertilionidae family (*Myotis myotis, M. blythii, M. bechsteinii, M. emarginatus, M. nattereri, M. mystacinus, M. capaccinii, M. daubentonii, Miniopterus schreibersii, Barbastella barbastellus, Plecotus austriacus*, and *P. auritus*) [34–36, 38]. *M. alcathoe*, recorded in this study, has been newly registered for Dupnisa Cave System. The maximum number of bats recorded in Dupnisa Cave System is 54,600 in hibernation, while 11,000 in nursery. Dupnisa Cave System is used for hibernating by the majority (83%) of the total number of bats recorded, while it is used for breeding and nursing by the minority (17%). The three parts of the cave system were used by different species to varying degrees according to the season. Sulu Cave is used only for hibernating, while Kız Cave and Kuru Cave are used for both hibernating and nursery (**Figure 6**) [36, 38].

In Dupnisa Cave System, 99% of bat colonies are composed of six species, *M. schreibersii* (78%), *M. myotis*/*blythii* (8%), *R. euryale* (6%), *R. ferrumequinum* (4%), and *M. capaccinii* (3%).


**Table 1.** The length measurements and mean microclimate data of Dunisa Cave System.

**Figure 6.** The maximum monthly number of bats recorded in a single survey in the three parts of Dupnisa Cave System. The data were collected from 2002 to 2010.

The biggest aggregations of the species recorded in a single survey in Dupnisa Cave System are *M. schreibersii* (45,600) in hibernation, *M. myotis*/*blythii* (4300) in hibernation, *R. euryale* (3600) in nursery, *R. ferrumequinum* (2200) in hibernation, *M. capaccinii* (1800) in hibernation, *R. mehelyi* (300) in nursery, *R. blasii* (200) in nursery, *M. emarginatus* (93) in hibernation, *R. hipposideros* (73) in hibernation, *M. daubentonii* (56) in hibernation, *M. mystacinus* (19) in hibernation, *M. bechsteinii* (six) in hibernation, *M. alcathoe* (five) in hibernation, *M. nattereri* (three) in hibernation, and *P. auritus* (one) in hibernation [36, 38].

While *Myotis* species mainly use Sulu Cave for hibernating, *Rhinolophus* species use both Sulu Cave and Kız Cave. On the other hand, *Myotis* species only use Kuru Cave for breeding and nursing, while *Rhinolophus* species use both Kuru Cave and Kız Cave. Although *M. schreibersii* is the most numerous species in Dupnisa Cave System, it does not use the cave system for breeding and nursing. However, unbred females and males of the species use Kuru Cave and Kız Cave only to spend the summer. Instead, *M. schreibersii* migrates to other suitable underground habitats in the area such as Koyunbaba Cave for breeding and nursing. In winter roosts, bat colonies are usually formed by one species. However, *M. myotis/M. blythii* and more rarely in smaller colonies *M. schreibersii/R. ferrumequinum* and *R. euryale/ R. mehelyi*/*R. blasii* can be seen together in the same roosts (**Figure 7**). On the other hand, summer colonies are of multi-species. Only *R. hipposideros* does not mix in with other species. In winter roosts, the two sexes are found together, whereas in summer roosts the two sexes are rarely found together.

The observation that the bats in the cave system always formed colonies at the same points depending on the seasons led to the belief that the rock characteristics, temperature, and humidity are the factors affecting roost selection. Paksuz et al. [36] emphasize that the main factor shaping the use of the cave system by the bats at various degrees is the microclimate. The temperature of Sulu Cave is low for breeding while the temperature of Kuru Cave is Important Caves in Turkish Thrace for Bats: Dupnisa Cave System and Koyunbaba Cave http://dx.doi.org/10.5772/intechopen.68836 89

**Figure 7.** The hibernation colonies of the bats in Dupnisa Cave System: a mixed colony of species *M. schreibersii* and *R. ferrumequinum* (a), a large colony of *M. schreibersii* (b).

high for wintering. Although the winter temperature is higher in Kız Cave than in Kuru Cave, Kız Cave is used for hibernating by the bats. The two entrances of Kuru Cave and its connection with Sulu Cave indicate that it may be more affected by temperature fluctuations and airflows, which may be the reason why the cave is preferred less than the other caves for hibernating. The humidity in winter is variable in all the three caves, while it is similar in summer. The specific roost requirements of bat species limit the use of many caves by bats. Thus, providing alternative conditions makes caves pretty appropriate roost for bats throughout the year. Therefore, Dupnisa Cave System, which offers alternative microclimatic conditions in the different parts, may be an important opportunity for many bats because the appropriate roosts will be more limited in the future, as global warming will become increasingly prevalent.

The biggest aggregations of the species recorded in a single survey in Dupnisa Cave System are *M. schreibersii* (45,600) in hibernation, *M. myotis*/*blythii* (4300) in hibernation, *R. euryale* (3600) in nursery, *R. ferrumequinum* (2200) in hibernation, *M. capaccinii* (1800) in hibernation, *R. mehelyi* (300) in nursery, *R. blasii* (200) in nursery, *M. emarginatus* (93) in hibernation, *R. hipposideros* (73) in hibernation, *M. daubentonii* (56) in hibernation, *M. mystacinus* (19) in hibernation, *M. bechsteinii* (six) in hibernation, *M. alcathoe* (five) in hibernation, *M. nattereri* (three) in

**Figure 6.** The maximum monthly number of bats recorded in a single survey in the three parts of Dupnisa Cave System.

While *Myotis* species mainly use Sulu Cave for hibernating, *Rhinolophus* species use both Sulu Cave and Kız Cave. On the other hand, *Myotis* species only use Kuru Cave for breeding and nursing, while *Rhinolophus* species use both Kuru Cave and Kız Cave. Although *M. schreibersii* is the most numerous species in Dupnisa Cave System, it does not use the cave system for breeding and nursing. However, unbred females and males of the species use Kuru Cave and Kız Cave only to spend the summer. Instead, *M. schreibersii* migrates to other suitable underground habitats in the area such as Koyunbaba Cave for breeding and nursing. In winter roosts, bat colonies are usually formed by one species. However, *M. myotis/M. blythii* and more rarely in smaller colonies *M. schreibersii/R. ferrumequinum* and *R. euryale/ R. mehelyi*/*R. blasii* can be seen together in the same roosts (**Figure 7**). On the other hand, summer colonies are of multi-species. Only *R. hipposideros* does not mix in with other species. In winter roosts, the two sexes are found together, whereas in summer roosts the two sexes are

The observation that the bats in the cave system always formed colonies at the same points depending on the seasons led to the belief that the rock characteristics, temperature, and humidity are the factors affecting roost selection. Paksuz et al. [36] emphasize that the main factor shaping the use of the cave system by the bats at various degrees is the microclimate. The temperature of Sulu Cave is low for breeding while the temperature of Kuru Cave is

hibernation, and *P. auritus* (one) in hibernation [36, 38].

The data were collected from 2002 to 2010.

88 Cave Investigation

rarely found together.

In Dupnisa Cave System, a conservation plan is applied for the protection of the bats and the cave system according to the seasonal use of the cave system by bats. This protection plan includes an appropriate visitor schedule and gate construction. The visitor schedule was arranged according to the seasonal use of Dupnisa Cave System by bats. The entrances of cave system where tourist circuits placed in were closed with horizontal angle iron gates to control the human disturbance. The other entrances of the cave system, outside of the tourist area, have been left to the natural state to minimize the negative effects of the two doors that can disturb the bats. In addition to these, some arrangements have been made for visitors and the use of lighting system. The protection of the caves and the bats will be possible only if the precautions that are taken and the suggestion that have been made are applied carefully [38].

Paksuz and Özkan [38] stated that the seasonal usage patterns of the parts in Dupnisa Cave System by the bats are completely preserved in periods of before and after tourist mobility (**Figure 8**). The authors also emphasized that there is no decrease in the total number of the bats in Dupnisa Cave System following the opening period tourist mobility. Moreover, they found a statistically significant increase after the tourist mobility only in Kız Cave, which is closed to tourism and ungated. This increase may indicate that the bats prefer to use the caves which are not visited by humans and tourist mobility. It seems as if Kız Cave, which is

**Figure 8.** The monthly population sizes of the bats in the periods before and after tourist mobility in Dupnisa Cave System.

closed to tourism and ungated in Dupnisa Cave System, is a good opportunity to minimize the potential negative effects of the tourism activities in Sulu Cave and Kuru Cave on the bats. These results show that the protection program prepared for the protection of Dupnisa Cave System and bats is sustainable and must be applied meticulously.

#### **3.3. Microclimate of Koyunbaba Cave**

Koyunbaba Cave has different microclimatic conditions according to stations and seasons (**Table 2**) [37]. While the summer temperature in Koyunbaba Cave varies from 10 to 24°C, the winter temperature varies from 5 to 16°C. In summer, while the highest mean temperature is in station 4 (17.1°C), the lowest mean temperature is in station 7 (12.3°C). The highest (15.2°C) and lowest (5.2°C) mean temperatures in winter are in station 1. The humidity in Koyunbaba Cave varies from 58 to 98% depending on seasons and stations.


**Table 2.** The mean microclimate data and location of the roosts in Koyunbaba Cave.

#### **3.4. Bats of Koyunbaba Cave**

closed to tourism and ungated in Dupnisa Cave System, is a good opportunity to minimize the potential negative effects of the tourism activities in Sulu Cave and Kuru Cave on the bats. These results show that the protection program prepared for the protection of Dupnisa Cave

**Figure 8.** The monthly population sizes of the bats in the periods before and after tourist mobility in Dupnisa Cave

Koyunbaba Cave has different microclimatic conditions according to stations and seasons (**Table 2**) [37]. While the summer temperature in Koyunbaba Cave varies from 10 to 24°C, the winter temperature varies from 5 to 16°C. In summer, while the highest mean temperature is in station 4 (17.1°C), the lowest mean temperature is in station 7 (12.3°C). The highest (15.2°C) and lowest (5.2°C) mean temperatures in winter are in station 1. The humidity in Koyunbaba

> **Winter temp. (°C)**

**Summer hum.** 

**Winter hum. (%)**

**(%)**

System and bats is sustainable and must be applied meticulously.

Cave varies from 58 to 98% depending on seasons and stations.

**(°C)**

**Table 2.** The mean microclimate data and location of the roosts in Koyunbaba Cave.

 Hall 17.0 9.3 66.7 68.6 Room 15.1 12.8 83.7 89.6 Corridor 12.6 8.1 75.9 86.0 Hall 17.1 9.4 68.9 76.2 Room 13.7 11.4 88.4 95.0 Hall 13.8 9.5 91.6 89.6 Corridor 12.3 7.9 75.7 80.4

**3.3. Microclimate of Koyunbaba Cave**

System.

90 Cave Investigation

**Stations Roost location Summer temp.** 

In the studies conducted until now, 11 species of bats have been recorded in Koyunbaba Cave. Five of these species belong to Rhinolophidae family (*R. ferrumequinum, R. hipposideros, R. euryale, R. mehelyi*, and *R. blasii*) and six of them belong to Vespertilionidae family (*M. myotis, M. blythii, M. emarginatus, M. capaccinii, M. schreibersii*, and *P. austriacus*) [34, 37]. The maximum number of bats recorded in a single survey in Koyunbaba Cave is 29,500 in summer, while 600 in winter. Koyunbaba Cave is used by the majority (92%) of the total bat numbers for breeding and nursing, while it is used by the minority (8%) for hibernating (**Figure 9**) [37].

Seven species constitute 98% of the bat colonies in Koyunbaba Cave, *M. schreibersii* (55%), *M. myotis/blythii* (25%), *M. capaccinii* (7%), *R. mehelyi* (6%), *R. euryale* (3%), and *R. ferrumequinum* (2%). The largest aggregations of the species recorded in a single survey in Koyunbaba Cave are *M. schreibersii* (17,710), *M. myotis/blythii* (7840), *M. capaccinii* (2230), *R. mehelyi* (1850), *R. euryale* (859), *R. ferrumequinum* (788), *M. emarginatus* (356), *R. blasii* (176), *R. hipposideros* (10), and *P. austriacus* (one) [37].

The cave is used by species of *R. ferrumequinum, R. mehelyi*, and *R. hipposideros* for both breeding/nursing and hibernating throughout the year, while it is used by species of *R. blasii, R. euryale, M. myotis/blythii, M. capaccinii, M. emarginatus*, and *M. schreibersii* for breeding/nursing in the summer (**Figure 10**).

The roosts in Koyunbaba Cave are used by bats for various degrees and purposes according to species. The rooms and halls of Koyunbaba Cave are used as summer roost, while the corridors are used as winter roost. The selection of roost location in the cave by bats differed according to the species. *R. ferrumequinum, R. hipposideros, R. euryale, R. mehelyi*, and *M. emarginatus* use all roost types, while *R. blasii, M. myotis/blythii, M. capaccinii*, and *M. schreibersii* mainly use halls [37].

**Figure 9.** The maximum monthly number of bats recorded in a single survey in Koyunbaba Cave. The data were collected from 2007 to 2008.

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

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, and entrances.
