Modelling the distribution of bat activity areas for conservation in a Mediterranean mountain range

Abstract

There is a lack of studies designed to detect the most important areas for bat con-servation. In this context, areas of high bat activity have been rarely considered inthe delimitation of protected areas for bats, which are generally focused on the pro-tection of roosting sites. This has been due to the difficulties of sampling the distri-bution of these nocturnal animals when moving at night. This methodologicalconstraint has been overcome by the development of bioacoustic sampling, whichallows mapping the occurrence of active bats over large areas. In this study, weuse bat detectors to sample the distribution of bat activity in central Spain. Thisregion is under the environmental effects of a mountain range (Guadarrama Moun-tains) and the urban encroachment of the city of Madrid. The occurrences providedby the detectors were used to produce species distribution models of which theresulting layers were arranged to detect the most suitable areas for bat richness andrarity indices. We performed a gap analysis to explore whether the areas mostcommonly used by active bats are covered by the current network of protectedareas. The results showed that the best areas of high bat activity are located at thepiedmont of the mountains and that most of these areas overlap with the existingnetwork of protected areas. The best areas for bats excluded the most urbanizedareas and within a similar urban gradient, protected areas tended to be locatedwithin the best sites for conservation. These results suggest that bats currently ben-efit from a network of protected areas initially aimed to protect birds and habitats(Natura 2000). In addition, monitoring areas of high bat activity could complementroosting site protection in the conservation of bat assemblages.