Šikšnosparnių (Chiroptera) rudeninės migracijos tyrimai Oderio upės slėnyje pietvakarių Lenkijoje ; The research of bat (chiroptera) autumn migration in the oder river valley in southwestern poland

We studied migration of bats along Odra river valley in SW Poland for four nights in September 2010. We carried out all-night acoustical observations of bats flying at the river North-Soutth and East-West directions segments, in the forest, grassland and on the outer wood. The direction on bats’ movements were determined on the basis of echolocation sequences order recorded by two frequency division ultrasound detectors. We noted activity for eight species: Myotis daubentonii, M. dasycneme, M. brandti, Nyctalus noctula, Pipistrellus nathusii, P. pipistrellus, P. pygmaeus, Eptesicus serotinus. Our results show that Myotis daubentonii, Pipistrellus nathusii, P. pygmaeus use only the river as the migration corridor, but not all valley of the river. Eptesicus serotinus and P. pipistrellus directional flyings were detected in the forest, but these data were unsufficient to relate the migratory way and the valley of the river. The great amount of undirectional flyings and nutrition signals of Nyctalus noctula in all places shows that this species uses all the valley for nutrition. Our results show that the activities of different bats species for twenty four hours are different at the river. The greatest counts of sequencies for Myotis daubentonii, Nyctalus noctula were registered in the evening: Myotis daubentonii – at 8 p.m., and Nyctalus noctula – at 7 p.m. Activities of Pipistrelus pygmaeus and Pipistrellus nathusii were similar during all night time. No activities of bats were detected in the daytime.