THE ROLE OF FRUIT BAT EIDOLON HELVUM AND AVIAN FRUGIVORES IN GUAVA SEED DISPERSAL AND TREE ESTABLISHMENT IN AGRICULTURAL LANDSCAPES IN VIHIGA, WESTERN KENYA BY ROGERS KATUA MAKAU, B. Sc. (Hons, University of Nairobi) (REG. NO. I56/79604/2012) Thesis submitted in partial fulfilment of the requirement for the award of the degree of Master of Science in Biology of Conservation, University of Nairobi. SCHOOL OF BIOLOGICAL SCIENCES COLLEGE OF BIOLOGICAL AND PHYSICAL SCIENCES MSC. BIOLOGY OF CONSERVATION UNIVERSITY OF NAIROBI SEPTEMBER, 2016 DECLARATION This thesis is my original work and has not been presented for award of a degree in any other university. Makau Rogers Katua Reg. No I56/79604/2012 Signature Date I confirm that this thesis has been submitted for examination with my approval as a supervisor. Dr. Robert Chira School of Biological Sciences University of Nairobi Signature Date ii DEDICATION This thesis is dedicated to all conservation practitioners in the world. iii AKNOWLEDGEMENTS My utmost gratitude goes to the Almighty God for the provision of strength, knowledge and understanding throughout the study period. I wish to express my sincere gratitude to my supervisors Dr. R. Chira and the late Dr. R. Okoola for their unwavering support, expertise, guidance and tireless efforts that made completion of this study possible. I extend my appreciation to Mr. Kitheka, a botanist from the National Museums of Kenya Herbarium Section, for helping in plant species identification. I am also grateful to Mr. Odalo, my field assistant. He made my data collection work easier and enjoyable. My research would not be complete if it were not for his encouragement and support. Special thanks go to Mr. Simon Musila of National Museums of Kenya, Department of Mammalogy and Dr. P. Webala of Maasai Mara University for their precious advice and encouragement that enabled me to pursue this study on bats. My gratitude goes to Gilbert Kosgey of KENWEB, National Museums for his assistance in editing the thesis. Sincere thanks go to my wife (Jane Wayua) and children (Victoria, Prosper and Blessing) for their support and encouragement throughout my research work. Finally, I thank the Bat Conservation International (BCI) through the University of Nairobi for granting me a scholarship to pursue my research project. They have made my dream come true. iv TABLE OF CONTENTS TITTLE PAGE………………...…………………………………………………………………i DECLARATION ...................................................................................................................... ii DEDICATION ........................................................................................................................ iii AKNOWLEDGEMENTS ....................................................................................................... iv TABLE OF CONTENTS ..........................................................................................................v LIST OF FIGURES .............................................................................................................. viii LIST OF TABLES .................................................................................................................. ix LIST OF PLATES ....................................................................................................................x ABBREVIATIONS AND ACRONYMS ................................................................................ xi ABSTRACT............................................................................................................................ xii CHAPTER ONE: INTRODUCTION ......................................................................................1 1.1 Problem statement and justification of the study ............................................................4 1.2 General and Specific objectives .....................................................................................6 1.3 Research hypotheses .....................................................................................................6 CHAPTER TWO: LITERATURE REVIEW ..........................................................................7 2.1 The straw-coloured fruit bat (Eidolon helvum) ...................................................................7 2.2 Frugivorous birds ..............................................................................................................8 2.3 Frugivory and seed dispersal............................................................................................ 11 2.4 Dietary analysis of fruit visiting bats and birds ................................................................ 14 2.5 Factors influencing dispersed seed germination ............................................................... 16 2.5.1 Seed dispersal effectiveness ...................................................................................... 16 2.5.2 Gut conditioning ....................................................................................................... 18 2.6 The importance of seed dispersal to plant regeneration .................................................... 19 CHAPTER THREE: STUDY AREA, MATERIALS AND METHODS .............................. 21 3.1 Study area........................................................................................................................ 21 3.1.1 Location ................................................................................................................... 21 3.1.2 Climate ..................................................................................................................... 22 v 3.1.3 Topography and soils ................................................................................................ 22 3.1.4 Fauna ........................................................................................................................ 23 3.1.5 Vegetation ................................................................................................................ 23 3.1.6 Population and social-economic activities ................................................................. 24 3.2 Materials and Methods .................................................................................................... 24 3.2.1 Sampling design ....................................................................................................... 24 3.2.2 Frugivore observations.............................................................................................. 25 3.2.2.1 Selection of focal trees ....................................................................................... 25 3.2.2.2 Frugivores visits ................................................................................................. 26 3.2.3 Guava seed germination ............................................................................................ 27 3.2.3.1 Seed collection ................................................................................................... 27 3.2.3.2 Seed germination ............................................................................................... 27 3.2.4 Seed rain, seedling establishment and tree density sampling ..................................... 29 3.2.4.1 Seed rain and spats sampling .............................................................................. 29 3.2.4.2 Seedling and tree density sampling..................................................................... 30 3.3 Data analysis ................................................................................................................... 32 CHAPTER FOUR: RESULTS ............................................................................................... 33 4.1 Frugivore observations .................................................................................................... 34 4.1.1 Eidolon helvum visits ................................................................................................ 34 4.1.2 Time of visits by E. helvum fruit bats on guava trees ................................................. 34 4.1.3 Distance between focal trees and E. helvum visits ..................................................... 35 4.1.4 Activities carried out by frugivores on guava trees .................................................... 36 4.1.5 Comparison between E. helvum and avian frugivores visits....................................... 37 4.1.6 Avian observations within sites ............................................................................... 39 4.1.7 Time of visits by avian frugivores on P. guajava trees .............................................. 41 4.2 Seed germination ............................................................................................................. 41 4.3 Seed rain, seedling and tree densities ............................................................................... 43 4.3.1 Seed rain density ....................................................................................................... 43 4.4.2 Seedling density ........................................................................................................ 44 vi 4.4.3 Tree density and diversity ......................................................................................... 45 CHAPTER FIVE: DISCUSSION, CONCLUSION AND RECOMMENDATIONS ........... 48 5.1 Discussion ....................................................................................................................... 48 5.1.1 Frugivore