Foraging habitats of bats in southern Finland

We determined the foraging habitats of the northern bat Eptesicus nilssonii (Keyserling et Blasius, 1839), Brandt's bat Myotis brandtii (Eversmann, 1845), whiskered bat Myotis mystacinus (Kuhl, 1819), Daubenton's bat Myotis daubentonii (Kuhl, 1819) and brown long-eared bat Plecotus auritus (Linnaeus, 1758) in southern Finland. Among these species, we compared the diversities of foraging habitats, linear feature preference and the bats' tendencies to forage simultaneously. Eptesicus nilssonii was the most opportunistic, foraging in a wide range of habitats. Myotis daubentonii (94%) foraged mainly on water habitats, while M. brandtii/mystacinus (89%) and P. auritus (66%) foraged mainly in forest habitats. The diversities of foraging habitats used by E. nilssonii and P. auritus were higher than those of M. brandtii/mystacinus and M. daubentonii. Both E. nilssonii and P. auritus foraged mostly alone or in small numbers, while M. brandtii/mystacinus tended to gather in large numbers to forage in the same habitat. Half of E. nilssonii and 46% of M. daubentonii foraged over linear features, while other species did not use linear features to such an extent. Management and conservation of foraging habitats are needed especially for M. brandtii/mystacinus and M. daubentonii, which are more specialized than E. nilssonii and P. auritus.