Ecological and socio-economic effects of industrial oil palm plantations in Southwest Cameroon Dissertation for the award of the degree "Doctor of Philosophy" Ph.D. Division of Mathematics and Natural Sciences of the Georg-August-Universität Göttingen within the doctoral program Biodiversity and Ecology of the Georg-August University School of Science (GAUSS) submitted by Denis Kupsch from Magdeburg, Germany Göttingen, 2019 Thesis Committee: Prof. Dr. Matthias Waltert, Conservation Biology/Workgroup on Endangered Species, Johann-Friedrich-Blumenbach Institute of Zoology and Anthropology Prof. i.R. Dr. Gerhard Gerold, Physical Geography, Institute of Geography Prof. Dr. Eckhard W. Heymann, Sociobiology/Anthropology, Johann-Friedrich-Blumenbach Institute of Zoology and Anthropology Member of the Examination Board: Reviewer: Prof. Dr. Matthias Waltert, Conservation Biology/Workgroup on Endangered Species, Johann-Friedrich-Blumenbach Institute of Zoology and Anthropology Second Reviewer: Prof. i.R. Dr. Gerhard Gerold, Physical Geography, Institute of Geography Further Members of the Examination Board: PD Dr. Sven Bradler, Animal Evolution and Biodiversity, Johann-Friedrich-Blumenbach Institute of Zoology and Anthropology Prof. Dr. Eckhard W. Heymann, Sociobiology/Anthropology, Johann-Friedrich-Blumenbach Institute of Zoology and Anthropology Prof. Dr. Teja Tscharntke, Agroecology, Department of Crop Sciences Prof. Dr. Kerstin Wiegand, Ecosystem Modelling, Büsgen-Institut Date of the oral examination: 30 September 2019 Table of contents Summary ............................................................................................................................... XI PART I - GENERAL INTRODUCTION ................................................................................................ Chapter 1 - Introduction .......................................................................................................... 3 1.1 The global oil palm development .................................................................................. 3 1.2 Plantation project and study area .................................................................................. 5 1.3 Research objectives and chapter outline ....................................................................... 6 1.4 References ..................................................................................................................... 8 PART II - THE CONSERVATION STATUS OF WILDLIFE IN AGROFORESTRY LANDSCAPES IN SOUTHWEST CAMEROON ............................................................................................................... Chapter 2 - The status of large mammals in Southwest Cameroon: How threatened wildlife disappears from an Afrotropical forest biodiversity hotspot ................................................ 15 2.1 Abstract ....................................................................................................................... 15 2.2 Introduction ................................................................................................................. 16 2.3 Material and methods .................................................................................................. 18 Study area ...................................................................................................................... 18 Data collection ............................................................................................................... 18 Data analysis .................................................................................................................. 19 2.4 Results ......................................................................................................................... 21 Relative mammal abundance trends from 2007 to 2014 in KNP and BMWS .............. 21 Chimpanzee and elephant population estimates in 2007 and 2014 ............................... 23 Relative mammal abundances in 2014 in four survey sites........................................... 23 Parameters affecting species distribution ...................................................................... 28 2.5 Discussion ................................................................................................................... 28 Recent large mammal abundance trends in BMWS and KNP ...................................... 28 Patterns and factors of large mammal distribution in a multi-use landscape context ... 29 2.6 Conclusions ................................................................................................................. 31 2.7 References ................................................................................................................... 33 2.8 Supplement .................................................................................................................. 39 V PART III - EFFECTS OF AGRO-INDUSTRY AND OTHER LAND USES ON BIODIVERSITY IN SOUTHWEST CAMEROON............................................................................................................... Chapter 3 - High critical forest habitat thresholds of native bird communities in Afrotropical agroforestry landscapes ................................................................................... 43 3.1 Abstract ....................................................................................................................... 43 3.2 Introduction ................................................................................................................. 43 3.3 Materials and methods ................................................................................................ 45 Study area ...................................................................................................................... 45 Bird sampling ................................................................................................................ 46 Data analysis ................................................................................................................. 46 3.4 Results......................................................................................................................... 49 Bird guild responses to forest cover .............................................................................. 49 Effects of community weights ...................................................................................... 51 Species-specific responses to forest cover .................................................................... 52 3.5 Discussion ................................................................................................................... 54 Differential responses to changes in forest cover ......................................................... 54 Bird species composition at intermediate deforestation ............................................... 56 Critical forest thresholds in tropical bird conservation ................................................. 57 3.6 References ................................................................................................................... 58 3.7 Supplement ................................................................................................................. 64 Chapter 4 - Extinction thresholds and negative responses of Afrotropical ant-following birds to forest cover loss in oil palm and agroforestry landscapes ....................................... 83 4.1 Abstract ....................................................................................................................... 83 4.2 Introduction ................................................................................................................. 84 4.3 Materials and methods ................................................................................................ 85 Study area ...................................................................................................................... 85 Data collection .............................................................................................................. 87 Data analysis ................................................................................................................. 89 4.4 Results......................................................................................................................... 90 4.5 Discussion ................................................................................................................... 93 VI 4.6 Conclusions ................................................................................................................. 97 4.7 References ................................................................................................................... 97 4.8 Supplement ................................................................................................................ 103 Chapter 5 - Congo Grey Parrot Psittacus erithacus densities in oil palm plantation, agroforestry mosaic and protected forest in SW Cameroon ............................................... 107 5.1 Abstract ..................................................................................................................... 107 5.2 Introduction ............................................................................................................... 107 5.3 Materials and methods .............................................................................................. 109 Study area ...................................................................................................................