Cape Mountain Zebra (Equus Zebra Zebra) Habitat Use and Diet in the Bontebok National Park, South Africa
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Cape mountain zebra (Equus zebra zebra) habitat use and diet in the Bontebok National Park, South Africa by Taniia Strauss Submitted in fulfilment of the requirements for the degree of Masters of Technology to be awarded at the Nelson Mandela Metropolitan University January 2015 Supervisor: Prof. L.H. Watson DECLARATION I, Taniia Strauss (student number 20106975), hereby declare that the thesis for Degree of Masters of Technology to be awarded is my own work, and has not previously been submitted for assessment or completion of any postgraduate qualification to another University or for another qualification. _________________ Taniia Strauss Official use: In accordance with Rule G4.6.3, 4.6.3 A treatise/dissertation/thesis must be accompanied by a written declaration on the part of the candidate to the effect that it is his/her own work and that it has not previously been submitted for assessment to another University or for another qualification. However, material from publications by the candidate may be embodied in a treatise/dissertation/thesis. I ABSTRACT Cape mountain zebra habitat utilization and diet in the dystrophic fynbos habitat of the Bontebok National Park was found to be highly selective. Mountain zebra concentrated in specific sectors and habitat types in the park on a seasonal basis, preferring recently burnt habitat with a veld age younger than one year in all seasons, except during the warm, dry summer. Proteoid Fynbos with a veld age between one and five years was preferred in the cool winter, while Drainage Lines and the fringes of Inland Pans were preferred during summer. Asteraceous Fynbos was avoided, irrespective of veld age, as well as all other habitats with a veld age greater than five years. Within habitat types with a veld age greater than one year, specific sites were selected and avoided on a seasonal basis, which were found to differ in terms of habitat suitability, based on the availability of dietary plant species. The annual diet consisted of 72.6% grass, 11.8% restio, 5.9% sedge, 8.8% geophyte and less than 1% forb and shrub species. Three grass species formed the bulk of the annual diet, Themeda triandra, Cymbopogon marginatus and Eragrostis curvula, for which leaf use was greater than stem use. Themeda trianda was preferred throughout the year, but contributed to the diet in greatest proportion in the warm, dry summer, when it was available at greatest leaf height and diameter. Cymbopogon marginatus was preferred during the cool winter, when diet composition and greenness was also greater than in other seasons. Preference of Cymbopogon marginatus decreased as leaf height and diameter increased. Eragrostis curvula was preferred in the warm autumn, when it composed the largest proportion of the diet, and selection of this species at feeding sites was based on both greenness and volume. In summer mountain zebra also preferred grass stems and inflorescences of Aristida diffusa, Stipagrostis zeyheri and Briza maxima. During the cool spring the diet included stems and inflorescences of sedges and restios, primarily Ischyrolepis capensis, and in autumn, dry bulbs of the geophyte Moraea collina were utilized. Habitat utilization, as well as grass height and greenness surveys in the Recently Burnt Area, and the nutritional status of mountain zebra was found to be in line with the Summer Nutritional Stress Hypothesis. The hypothesis proposes that the harsh climatic conditions of the area during summer are linked to the low availability of C4 grass, on which grazers would depend in summer. This is II supported by the avoidance of the Recently Burnt Area in summer, and the preference of species like Themeda triandra during summer despite low greenness levels. Faecal nitrogen and phosphorus for mountain zebra in Bontebok National Park and De Hoop Nature Reserve were at minimum levels during the warm seasons. Faecal nitrogen was below the threshold for dietary deficiency in all seasons except spring, and faecal phosphorus was above the threshold for deficiency during two seasons only. The findings of this study are in line with other recent work on mountain zebra in the Baviaanskloof suggesting that, due to a high required rate of forage intake, mountain zebra are limited by both poor resource quantity and quality in dystrophic fynbos ecosystems. III ACKNOWLEDGEMENTS I wish to acknowledge the following individuals and organizations for imperative support received during this study: To my supervisor, Prof. Laurence H. Watson, thank you for your meticulous guidance and support throughout this research journey as well the compilation of the thesis, and for convincing me that I have what it takes to complete such an important assignment. To Tineke Kraaij, thank you for your dedicated guidance, patience and support, especially with plant identification, research advice and proof reading. To Benjamin Wigley and Jeannette Pauw, thank you for your assistance with statistical analyses and research advice. To Corli Coetsee and Anton Schmidt, thank you for the pertinent comments and advice. For assistance and clarification in the plant communities of the BNP and plant identification, my sincere thanks to Jan Vlok, and also to Claire Archer and Nick Helme, for valued assistance in plant identification. For clarification and assistance in the literature search, thank you Elton le Roux, Sue Milton and the library staff at the Saasveld campus of NMMU. Thank you to the National Research Foundation and Nelson Mandela Metropolitan University for funding this project, in the form of research scholarships. Also to South African National Parks and Cape Nature for permits granted, and Bontebok National Park management and staff, especially Roland January, Siviwe Nondobo, Gerta Stuart and Luzzaan Gertse, for guidance and assistance during field work. Also to De Hoop Nature Reserve and Cape Nature ecological coordinator, Johan Huisamen, thank you for your advice and assistance with field work. To Carina Steenekamp and the Swellendam Municipality, thank you for discounted accommodation during field work. To my father, David J. Strauss, thank you for instilling in me a love for nature, for nurturing my inquisitive mind, and unselfishly encouraging me to embark on this research journey in such a difficult time for our family. I miss you and I know you IV would have taken great pride in reading this thesis. Thank you to my mother, Suzette Strauss, for believing in me, and for every encouraging word that edged me all the way to the finishing line, despite so many challenges. To my partner “in crime”, Benjamin Parker, thank you for all your love and support, and for persevering with me; even when it was virtually impossible to do so. To my daughter, Enya S. Parker Strauss, thank you for being so patient with your mommy through all the missed play dates, early mornings and quick meals. To my sister, Liz Strauss, thank you for being my shoulder to lean on from the other side of the planet, and for all the health advice and support, without which I might not have made it this far. To Laurinda Uys, thank you for all your help during the field work, and caring for little Enya during sampling days. To the rest of my super support system, the friends and family who encouraged me through the many ups and downs, and helped with accommodation and looking after Enya when I was working on this project: Angela Frey, Michelle Cheyne, Juliet Perkin, Lindi Hewitt-Coleman, Sandra Parker, Ilse Harms, Taryn de Witt, Marcelle Sutton and Kara Marais, thank you. And last but foremost, thank you to all my fellow Masters student friends, for your advice and light-hearted support, especially Tatenda Mapeto, Thea Buckle, Jama Mashele, Samantha Mc Culloch, Lisa Heider, Andrew Jackson, Hannes van Zyl, Sikhumbuzo Nxymalo and Kate Southey. V To my dad, David J. Strauss and my mom, Suzette Strauss VI TABLE OF CONTENTS DECLARATION ........................................................................................................... I ABSTRACT ................................................................................................................ II ACKNOWLEDGEMENTS ......................................................................................... IV TABLE OF CONTENTS ........................................................................................... VII LIST OF FIGURES ..................................................................................................... X LIST OF TABLES ...................................................................................................... XI CHAPTER 1: INTRODUCTION ............................................................................... 1 1.1. BACKGROUND ............................................................................................... 1 1.2. MOUNTAIN ZEBRA TAXONOMY AND CONSERVATION STATUS .............. 2 1.3. LITERATURE REVIEW ................................................................................... 5 1.3.1. HABITAT USE ................................................................................... 5 1.3.2. DIET COMPOSITION AND PREFERENCE .................................... 11 1.3.3. FACTORS INFLUENCING FORAGE SELECTION ........................ 13 1.3.4. NUTRITIONAL STATUS ................................................................. 17 CHAPTER 2: STUDY SITE ................................................................................... 20 2.1. LOCATION AND TOPOGRAPHY ................................................................