Foraging strategies of an aerial-hawking insectivore, the Common noctule bat Nyctalus noctula Inaugural-Dissertation to obtain the academic degree Doctor rerum naturalium (Dr. rer. nat.) submitted to the Department of Biology, Chemistry and Pharmacy of Freie Universität Berlin by MANUEL ROELEKE 2018 This dissertation was conducted between October 2015 and December 2018 at the Leibniz Institute for Zoo- and Wildlife Research in the Forschungsverbund Berlin e.V. under the supervision of PD Dr. Christian C. Voigt. 1st Reviewer: PD Dr. Christian C. Voigt (Leibniz Institute for Zoo- and Wildlife Research in the Forschungsverbund Berlin e.V., and Freie Universität Berlin) 2nd Reviewer: Prof. Dr. Britta Tietjen (Freie Universität Berlin) Date of defense: 12.06.2019 Acknowledgements Many thanks to my supervisor Christian C. Voigt for his longstanding support, his trust, his enthusiasm, and his company during many exciting field trips. Thanks to the whole BioMove group for pushing forward movement ecology, thus making this research possible, and thanks for intellectual and administrative support. Thanks to the DFG for funding. Special thanks to Florian Jeltsch for his relentless enthusiasm. Many thanks to my colleagues and friends Oliver Lindecke and Cedric Scherer for discussing science and sharing the usual ups and downs of PhD life. Thanks to Viktoriia Radchuk for statistical advice. Thanks to the colleagues who helped revising this work. Many thanks to Anja Fritz and Rolf Struikmans for support in the field and discussions. Thanks to Gernot Verch and the crew from the Zalf field station in Dedelow for administrative support during field work. Thanks to all members of the batlab and many spontaneous helpers without whom fieldwork would not have been possible. Thanks to Friederike Klingler for sharing data, to Lilith Johannsen for extensive help with the playback experiments, and to Maris Pärn for help with the insect samples. Thanks to Britta Tietjen for reviewing this thesis. Special thanks to Torsten Blohm, Uwe Hoffmeister, and Tobias Teige for their longstanding engagement in bat conservation, for sharing their knowledge about bats, and for their eager support. TABLE OF CONTENT SUMMARY ...................................................................................... 1 ZUSAMMENFASSUNG ........................................................................ 4 GENERAL INTRODUCTION ................................................................... 7 MOVEMENT OF ANIMALS ........................................................................................ 7 FORAGING ECOLOGY ............................................................................................. 7 INTEGRATION OF MOVEMENT AND BIODIVERSITY RESEARCH .......................................... 9 BATS AS A MODEL FOR MOVEMENT AND BIODIVERSITY RESEARCH ................................ 11 Importance and generalisability ................................................................. 11 Study of ecological key mechanisms ......................................................... 11 Research feasibility ................................................................................... 12 THESIS OUTLINE ................................................................................................. 14 CHAPTER ONE - ENVIRONMENTAL EFFECTS ON MOVEMENT PATTERNS ....... 15 ABSTRACT ........................................................................................................ 15 BACKGROUND .................................................................................................... 16 METHODS ......................................................................................................... 18 Study site and GPS tracking ....................................................................... 18 Data acquisition and processing ................................................................ 19 Habitat use and movement behaviour ........................................................ 20 Statistics ................................................................................................... 21 RESULTS .......................................................................................................... 22 Moonlight and flight altitude ...................................................................... 22 Moonlight and habitat use ......................................................................... 24 DISCUSSION ...................................................................................................... 27 Habitat use and the effect of moonlight ..................................................... 27 Conclusions .............................................................................................. 31 ACKNOWLEDGEMENTS ......................................................................................... 32 REFERENCES CHAPTER ONE .................................................................................. 32 CHAPTER TWO - COMPETITION AT FORAGING PATCHES .......................... 38 ABSTRACT ........................................................................................................ 38 INTRODUCTION .................................................................................................. 39 MATERIAL AND METHODS .................................................................................... 42 Study sites ................................................................................................ 42 Playback preparation ................................................................................. 43 Playback experiments ............................................................................... 43 Acoustic analysis ...................................................................................... 44 Insect trapping and analyses ..................................................................... 44 Data management and statistical analysis .................................................. 45 RESULTS .......................................................................................................... 46 Bat activity at waterbodies ......................................................................... 46 Insect trapping .......................................................................................... 46 Playback experiments ............................................................................... 49 DISCUSSION ...................................................................................................... 51 Seasonal shifts of habitat use .................................................................... 51 Seasonal shifts of prey availability ............................................................. 52 Playback experiments – post effect and density dependent response......... 53 Playback experiments – seasonal changes of competition ......................... 53 ACKNOWLEDGEMENTS ......................................................................................... 56 REFERENCES CHAPTER TWO ................................................................................. 56 CHAPTER THREE - FORAGING STRATEGIES IN DIFFERENT LANDSCAPES ....... 62 ABSTRACT ........................................................................................................ 62 INTRODUCTION .................................................................................................. 63 MATERIAL AND METHODS .................................................................................... 66 Animal tracking ......................................................................................... 66 Study sites ................................................................................................ 67 Analysis of ultrasound recordings .............................................................. 67 Analysis of movement and foraging behaviour ........................................... 68 Analysis of habitat use in ARM patches...................................................... 69 RESULTS .......................................................................................................... 71 Movement and foraging behaviour ............................................................. 71 Habitat use ................................................................................................ 73 DISCUSSION ...................................................................................................... 75 Movement and foraging behaviour ............................................................. 76 Habitat use ................................................................................................ 78 Possible shortcomings .............................................................................. 79 Conclusion ................................................................................................ 80 DATA AVAILABILITY ............................................................................................ 81 ACKNOWLEDGEMENTS ......................................................................................... 81 AUTHOR CONTRIBUTIONS ..................................................................................... 81 REFERENCES CHAPTER THREE .............................................................................. 81 GENERAL DISCUSSION ..................................................................... 87 ABIOTIC FACTORS INFLUENCE USE OF FORAGING HABITATS (CHAPTER ONE) ..................