Human-chimpanzee coexistence at Bossou, the Republic of Guinea: A chimpanzee perspective Kimberley Jane Hockings A thesis submitted for the degree of Doctor of Philosophy Department of Psychology University of Stirling March 2007 Table of Contents Table of Contents...................................................................................................... i List of Colour Plates ............................................................................................... iv Declaration ................................................................................................................v Abstract.................................................................................................................... vi Publications and Presentations............................................................................ viii Acknowledgements ...................................................................................................x Chapter 1: The Human-Primate Frontier..............................................................1 1.1 Culture and coexistence............................................................................2 1.2 Increasing human population....................................................................4 1.2.1 Use of terms.....................................................................................5 1.3 Factors affecting crop-raiding...................................................................6 1.4 Primates as crop-raiders............................................................................7 1.4.1 Crop-raiding by the great apes.......................................................10 1.5 Thesis structure.......................................................................................14 Chapter 2: The Study Site and Bossou Chimpanzee Community......................16 2.1 Location of the study site........................................................................17 2.2 Climatic variables ...................................................................................18 2.3 Vegetation...............................................................................................19 2.4 Human impact.........................................................................................19 2.5 Local beliefs............................................................................................21 2.6 History of research at Bossou .................................................................21 2.6.1 Subsistence behaviour....................................................................23 2.6.2 Demography...................................................................................23 2.7 The Bossou chimpanzee community ......................................................25 Chapter 3: Study Methods.....................................................................................28 3.1 Overview of methods..............................................................................29 3.2 Study period............................................................................................29 3.3 Habituation and visibility levels .............................................................30 3.3.1 Location of chimpanzees ...............................................................31 3.4 Rainfall and temperature.........................................................................31 3.5 Phenology ...............................................................................................32 3.6 Cultivar availability ................................................................................33 3.7 Chimpanzee behavioural sampling.........................................................36 3.7.1 Focal individual sampling.............................................................36 3.7.2 Scan sampling...............................................................................38 3.7.3 Ad libitum observations ................................................................39 3.8 Analyses..................................................................................................40 Chapter 4: Patterns of Wild Food and Cultivar Availability .............................41 4.1 Introduction.............................................................................................42 4.1.2 Monitoring forest fruit availability ................................................43 4.1.3 Hypotheses.....................................................................................45 4.2 Methods and analyses .............................................................................45 4.2.1 Wild fruit availability.....................................................................45 4.2.2 Cultivar availability .......................................................................46 4.3 Results.....................................................................................................47 i 4.3.1 Phenology patterns and wild food availability .............................47 4.3.2 Fallback resources.........................................................................51 4.3.3 Cultivar availability ......................................................................52 4.4 Discussion...............................................................................................61 Chapter 5: Crop-raiding: an Ecological Approach.............................................63 5.1 Introduction.............................................................................................64 5.1.2 Hypotheses....................................................................................68 5.2 Methods and analyses .............................................................................69 5.3 Results: Temporal variations in crop-raiding .........................................73 5.3.1 Crop-raiding frequencies ..............................................................73 5.3.2 Combined cultivars.......................................................................74 5.3.3 Simple-sugar fruits........................................................................78 5.3.4 Other simple-sugar cultivars.........................................................81 5.3.5 Complex carbohydrate/protein/lipid cultivars ..............................85 5.3 Results: Synthesis of wild and cultivated foods .....................................89 5.3.6 Oil-palm utilisation.......................................................................89 5.3.7 Wild feeding .................................................................................92 5.3.8 Fallback foods...............................................................................94 5.3.9 Dietary diversity ...........................................................................95 5.4 Discussion...............................................................................................96 5.4.1 Simple-sugar fruits........................................................................98 5.4.2 Other cultivars...............................................................................99 5.4.3 Wild fallback foods.....................................................................101 5.4.4 Culture in crop-raiding................................................................101 Chapter 6 – Part One: Crop-raiding: a Behavioural Approach ......................104 6.1 Introduction...........................................................................................105 6.1.2 Hypotheses..................................................................................110 6.2 Methods and analyses ...........................................................................111 6.3 Results: Daily activity patterns.............................................................113 6.3.1 Crop-raiding and fallback foods .................................................115 6.3 Results: Party formation .......................................................................116 6.3.2 Party spread and proximity.........................................................122 6.3.3 Number of adult males................................................................123 6.3 Results: Behavioural adaptations to crop-raiding.................................125 6.3.2 Vocalisations...............................................................................125 6.3.3 Transport of food ........................................................................127 6.3.4 Vigilance.....................................................................................128 6.4 Discussion.............................................................................................130 5.4.1 Activity budgets..........................................................................130 5.4.2 Party formation ...........................................................................131 5.4.3 Behaviours associated with crop-raiding....................................134 Chapter 6 – Part Two: Chimpanzees Share Forbidden Fruit..........................136 6.5 Introduction...........................................................................................137 6.5.1 Hypotheses..................................................................................140 6.6 Methods and analyses ...........................................................................140 6.7 Results...................................................................................................142 6.7.1 Foods shared by