ROOSTING AND FORAGING BEHAVIOR OF NATTERER BATS (MYOTIS-NATTERERI) CLOSE TO THE NORTHERN BORDER OF THEIR DISTRIBUTION

Seven nursery roosts and four roosts of male Myotis nattereri, Kuhl 18 18 were found in central Scotland at latitude 56-57 degrees N. Most we re in crevices in the stonework of man-made structures other than occu pied houses. Emergence occurred late in the evening, at an average lig ht intensity of 3.5 lux and emerging bats circled in dark, sheltered a reas outside roosts before departing along flyways towards foraging ar eas. Individuals departed from, and returned to, roosts in groups of 2 -6, and circling behaviour was repeated on returning to the roost. Dur ing pregnancy, bats from a nursery roost made one flight each per nigh t. This increased to an average maximum of 1.84 early in lactation and then decreased again to one around weaning. Night roosts were situate d in foraging areas and were used by M. nattereri for resting and groo ming, for suckling volant but incompletely weaned young and also. poss ibly, for information transfer. important foraging habitats a ere wood land edges, parkland, roadside vegetation and sheltered areas of water . Arthropod prey was captured both on the wing and by gleaning from fo liage, and the bats were able to vary their diet according to arthropo d availability. Overall, important prey included Diptera (both Nematoc era and higher flies), Trichoptera, Coleoptera and non-flying groups s uch as Hemiptera, Dermaptera, Arachnida and Opiliones.