DIETARY AND SPATIAL STRATEGIES OF GEMSBOK ( Oryx g. gazella ) AND SPRINGBOK ( Antidorcas marsupialis ) IN RESPONSE TO DROUGHT IN THE DESERT ENVIRONMENT OF THE KUNENE REGION, NAMIBIA Inaugural-Dissertation to obtain the academic degree Doctor rerum naturalium (Dr. rer. nat.) Submitted to the Department of Biology, Chemistry, Pharmacy of the Freie Universität Berlin by David Lehmann from Grenoble, France 2015 Logo credit: David Lehmann / Oryx Project L´homme qui, du désert ne saccage point la légende, ne peut subir l´outrage. Tahar Ben Jelloun Diese Dissertation wurde am Leibniz-Institut für Zoo- und Wildtierforschung in Berlin (Direktor: Prof. Dr. Heribert Hofer) im Zeitraum August 2009 bis Januar 2015 unter der Leitung von PD Dr. Christian C. Voigt angefertigt und am Institut für Biologie der Freien Universität Berlin eingereicht. 1. Gutachter: PD Dr. Christian C. Voigt 2. Gutachter: Prof. Dr. Britta Tietjen Disputation am: 14.04.2015 DIETARY AND SPATIAL STRATEGIES OF GEMSBOK ( Oryx g. gazella ) AND SPRINGBOK ( Antidorcas marsupialis ) IN RESPONSE TO DROUGHT IN THE DESERT ENVIRONMENT OF THE KUNENE REGION, NAMIBIA Inaugural-Dissertation to obtain the academic degree Doctor rerum naturalium (Dr. rer. nat.) Submitted to the Department of Biology, Chemistry, Pharmacy of the Freie Universität Berlin by David Lehmann from Grenoble, France 2015 This dissertation is based on the following manuscripts: 1. Lehmann D 1,8 , Mfune J.K.E 2, Gewers E 3, Brain C 4, & Voigt C.C 1, 8 (2013) Dietary Plasticity of Generalist and Specialist Ungulates in the Namibian Desert: A Stable Isotopes Approach . PloS one , 8(8), e72190 doi:10.1371/journal.pone.0072190 2. Lehmann D 1,8 , Mfune J.K.E 2, Gewers E 3, Brain C 4, & Voigt C.C 1,8 (2015) Individual variation of isotopic niches in grazing and browsing desert ungulates . Oecologia. doi:10.1007/s00442-015-3335-1 3. Lehmann D 1,8 , Mfune J.K.E 2, Gewers E 3, Cloete J 4, Aschenborn O.H-K5, Mbomboro L6, Kasoana S 7, Brain C 4, & Voigt C.C 1,8 (2015) Spatial movements of desert dwelling gemsbok ( Oryx g. gazella ) in response to spatial and temporal variation in plant productivity (Unpublished ) 1Department of Evolutionary Ecology, Leibniz Institute for Zoo and Wildlife Research, Berlin 10315 Germany 2University of Namibia (UNAM), Department of Biological Sciences, Windhoek 13301 Namibia 3Torra community-based conservancy office, Kunene Region, Bergsig 462 Namibia 4Wilderness Safaris Namibia, Windhoek 6850, Namibia 5Bwabwata Ecological Institute, Ministry of Environment and Tourism, Uhland Street Erf: 1593 & 842 , Windhoek, Namibia 6Anabeb community-based conservancy office, Kunene Region, P.O. Box 33, Kamanjab Namibia 7Sesfontein community-based conservancy office, Kunene Region, P.O. Box 39, Kamanjab, Namibia 8Freie Universität Berlin, Verhaltensbiologie, Takustr. 6, 14195 Berlin, Germany CONTENT ACKNOWLEDGEMENTS ………………………………………………………….……… 1 ZUSAMMENFASSUNG ……………………………………………………………….….... 5 SUMMARY ……………………………………………………………………………...…... 7 CHAPTER I General introduction …………………………………….…………………….………….….. 9 Outline of the study …………………………………………….…………………………... 21 CHAPTER II – MANUSCRIPT 1 Dietary Plasticity of Generalist and Specialist Ungulates in the Namibian Desert: A Stable Isotopes Approach …………………………………………………………………………… 28 CHAPTER III – MANUSCRIPT 2 Individual variation of isotopic niches in grazing and browsing desert ungulates ………….…. ……………………………………………………………………...... 54 CHAPTER IV– MANUSCRIPT 3 Spatial movements of desert dwelling gemsbok ( Oryx g. gazella ) in response to spatial and temporal variation in plant productivity…………………………………………………..…. 92 CHAPTER V General discussion …………………..…………………….………………………………..132 Conclusive remarks ………………………………………………………………………... 144 CURRICULUM VITAE …...………………………………………………………………151 ACKNOWLEDGMENTS __________________________________________________________________________________________ ACKNOWLEDGMENTS Over the past five years I have met nice and interesting people that deserve to be thanked for making this doctoral work possible. Above all, I would like to thank my supervisor PD Dr. Christian C. Voigt for hiring me as a doctoral student and for giving me the opportunity to develop the Oryx Project in Namibia. Thank you very much for your continuous and stimulating support during the past five years and for trusting me in successfully establishing this project. Thank you for giving me scientific guidance and credit over the years and across difficult, often adventurous, field and administrative conditions. Thank you very much for sharing your time and energy, knowledge and passion with me. I would like to thank Dr. John K.E. Mfune from the University of Namibia for his excellent collaborative work on this project, for his kindness and endless support and for believing in me. Thank you very much for your friendship, I hope we will have the occasion to do more work together. I am also deeply grateful to Prof. Dr. Britta Tietjen for kindly accepting to look upon the evaluation of this dissertation at the Free University of Berlin. I thank Dr. med. vet. Ortwin Aschenborn for performing the immobilization of my collared gemsbok in the Palmwag concession, for co-authoring my last manuscript and for the time we spent in the field together. As well, I would like to thank Prof. Heribert Hofer the director of the IZW for giving me the opportunity to work within this stimulating institution. I am also very thankful to Dr. Bettina Wachter, Jörg Melzheimer, Bernd Wasiolka, Rubén Portas and the entire team of the Cheetah Project in Namibia for providing valuable scientific inputs, for their logistic supports in Namibia and for all these pleasant braai and laughs that we had together under the Namibian sky. Hanging out with Jörg in Namibia allowed me to sharpen my bush skills and my knowledge of the great wilderness. I looked up to him and attempted to be as successful as he is in the field. I also thank you, Jörg, for giving me great camaraderie. As well, I am very thankful to my friends Sarah Benhaiem and Eve Davidian for the mutual support and for all the stimulating discussions and relevant feedbacks as we navigated through our respective doctoral works. 1 ACKNOWLEDGMENTS __________________________________________________________________________________________ This work would not have been possible without the state-of-the-art work of Anja Luckner, Karin Sörgel and Doris Fichte who analysed my samples in the laboratory. Thanks for your support during administrative works and the writing of export / import permits of samples. Furthermore, I would like to express my gratitude to Dr. Alexandre Courtiol for his help defining appropriate statistical analyses, for his feedbacks regarding my scientific ideas and for his great friendship. I would like to thank Dr. Stephanie Kramer-Schadt and her PhD students Milena Stillfried and Jürgen Niedballa for briefing me on habitat modelling. I must specifically thank Jürgen Niedballa for taking time to show me how to process satellite imageries. As well, I thank Beate Peter-Meyers and Cornelia Greulich for always providing me, in the briefest delay and even when I was deep into the wild, the relevant literatures to my study. I also thank Stephanie Vollberg, Katrin Hohnstädter, Silke Ehle, Dagmar Boras, Wolfgang Tauche and the entire administrative team who helped me to overcome the many challenges of the German Administration. I thank Kerstin Austen and Lydia Alnajjar from the Free University who help me with my thesis submission. I am graceful to all my colleagues and friends from the IZW; especially Karin Schneeberger, Sarah Troxell, Olga Heim, Simon Ghanem and Oliver Lindecke for reviewing my manuscripts, sharing humour, field stories and many beers. At this point, I would like to thank Renata Martins, my roommate and colleague at the IZW. Renata, thank you very much for sharing this slice of life with me. Now, I would like to thank all the people in Namibia that accepted me as I am and helped me building up this doctoral work from the very beginning to this very present moment. First of all I would like to thank the Ministry of Environment and Tourism, especially Kenneth Uiseb and Matheus Iita for their interests, supports and beliefs in my work. I also thank MET for providing research permits. I am incredibly indebted to the Torra, Anabeb and Sesfontein conservancy of the Kunene Region of Namibia for welcoming me as one of them in their communities and for allowing me to work freely in their territories. Here, I would like to specifically thank Janjte Rhyms, Benny Roman, Pascolena and Tallus Florry, Maggy Vries, Linus Mbomboro, Setven Kasaona, Anthony Dawids, Martoline Simon, Denzel Bezuidenhout, Bons Roman and Bernardus Simon. I also thank Pieter Kasaona, Ricky Tjipombo as well as all the game guards from Torra, Anabeb and Sesfontein conservancies. Without all these people, my work would not have been as successful. Thank you so much guys! 2 ACKNOWLEDGMENTS __________________________________________________________________________________________ I also thank the team of the Wilderness Safaris Namibia for getting involved in the Oryx Project, for their interest and logistic supports in the field and for allowing me to get shower and internet access at their tourist camps in Kunene. I particularly thank my co-author Dr. med. vet. Conrad Brain from Wilderness Safaris for his help setting up the project, his kindness and his valuable scientific inputs. I thank Eunice Karigus and Eifrida Hebach from the Desert Rhino Camp and Emsie Verwey