Bats (Mammalia, Chiroptera) from a cave area in NW Italy

Caves play an important role in bat ecology, offering natural roosting and wintering sites. In the reproductive period, bats need to find an effective foraging environment away from the cave entrance, but only few studies have considered the use of foraging habitats in the immediate proximity of the caves. We provide a list of 18 bat species and 5 bat acoustic groups observed in a system of 81 caves in NW Italy. Winter censuses carried out during 17 years showed an increase of the Greater Horseshoe bat, a species of conservation concern. In the summer period this rare species was also observed foraging in nearby areas. Recording of bat calls in the summer period was performed both at cave entrances and in three foraging habitats present in the area surrounding the cave (woods, agricultural mosaic with artificial light, dark mosaic). Light mosaics and woods showed the highest foraging activity (160.3 and 72.0 pass/hour), while woods and cave entrances were accessed by the largest number of bat species. Our survey improves the inventory of bat species in a poorly sampled area, and we recommend a reduced tourism access, thereby promoting preservation of bats.