Linking Behavioral Diversity with Genetic and Ecological Variation in the Nigeria-Cameroon Chimpanzee (Pan Troglodytes Ellioti) Ekwoge Enang Abwe
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Linking behavioral diversity with genetic and ecological variation in the Nigeria-Cameroon chimpanzee (Pan troglodytes ellioti) A Thesis Submitted to the Faculty of Drexel University by Ekwoge Enang Abwe in partial fulfillment of the requirements for the degree of Doctor of Philosophy March 2018 0 1 ©Copyright 2018 Ekwoge Abwe. All Rights Reserved 0 Dedication My dad Elias Abwe and sister Pastor Belinda Abwe 0 Acknowledgements This project was accomplished with the support and encouragement of many people. I am indebted to my committee: Katy Gonder, Bethan Morgan, Mesha Hunter-Brown, Jake Russell and Sean O’Donnell. Thank you for your advice and insightful comments in the design, data analysis and write up of this dissertation. I am particularly grateful to my advisor Katy Gonder for accepting me as her student and it has been a great privilege to work under her mentorship. I thank Katy for her continuous support through the entirety of this project including visiting me in the field. Katy’s advice and support in the design and execution of this project, both in the field and lab, and final write up of this document were invaluable. I would like to express my sincere gratitude to Bethan Morgan, my mentor for so many years. Among other things, Bethan read through my dissertation chapters and her insightful comments brought this project to fruition. I would also like to acknowledge the unwavering support of James Christie. James and Bethan have always believed in me! I would love to acknowledge the contributions of Sean O’Donnell, Mike O’Connor, Dana Venditti, Hilton Oyamaguchi, and Matt Mitchell in my data analyses. Sean introduced me to EstimateS which I used to compare plant species richness within and between my study sites. Dana helped me with principal component analyses and factor analyses of mixed data in R, and especially making the PCA and FAMD plots beautiful! Mike, Hilton and Matt provided insightful comments on my general data analyses. The field part of this project was possible because of contributions from various organizations and people in Cameroon. I am especially grateful to the San Diego Zoo Global – i Ebo Forest Research Project (EFRP) for logistical, material and technical support. The facilities provided by EFRP including transportation, office space and equipment, the Bekob and Njuma Research stations in the Ebo forest, and an army of field assistants made data collection possible. I would like to thank the EFRP field assistants including: Julius Ngwane, Solomon Ngongbia, Lappe Blaise, Celestin Njukang, Wilson Tuka, Stanley Enongene, Jean Melba, Marc Touob, Junior Kibong, Elie Liboho, Jonas Mam and Daniel Batouan. I am also indebted to ERFP staff including Daniel Mfossa, Marcel Ketchen, Christian Mbella, Abwe Enang, Wilson Tuka and Solomon Ngongbia for helping me to macroscopically assess chimpanzee fecal samples for dietary analysis. I am thankful to Josiane Agha for her assistance with data entry. Thank you to Felix Nkumbe, the tireless EFRP driver. Thanks to His Royal Highness Dipita Gaston, president of traditional rulers of communities around the Ebo forest for his dedication to biodiversity conservation and an enabling research environment. I am especially grateful to Wildlife Conservation Society, Cameroon for logistical and technical support in the Mbam & Djerem National Park (MDNP). I am thankful to Roger Fotso, Bernard Fosso, Eric Teguia, Arielle Noumbi, Arouna Forche, Jean Marie Elouna and Noel Yanjeu for facilitating my data collection at Ganga, MDNP. I also wish to express sincere gratitude to Albert Mounga the Conservator of the MNDP, and park rangers. My field data collection at Ganga was possible due a dedicated team of field assistants including Roger Doudjar, Daouda Betare, Thomas Elanga, Missa Jacques, Moise Bello, Eric Teguia, Fabrice Kentatchime, Flaubert Mba, Alvine Dadjo and Ruffin Ambahe. I want to acknowledge the skill and dedication of paddlers who ferried us up and down the Djerem River, braving the rapids and the hippos! I am particularly thankful to Roger, Fabrice, Alvine and Flaubert for leading data collection expeditions ii at Ganga while I was in Ebo forest or back at Drexel. I am equally indebted to Fabrice for help with data entry and scanning datasheets, and uploading these alongside photos and videos on the Gonder Lab Dropbox. Thanks to Barthelemy Tchiengue of the National Herbarium, Cameroon for botanical identification across Ebo forest and MDNP. Botanical inventories and identification were facilitated by Ruffin Ambahe, Marcel Ketchen, Fabrice Kentatchime, Lappe Blaise, Roger Doudjar, Daouda Betare, and Elanga Thomas. I am grateful to my family for their support. Special thanks to my wife Martha and my boys: Enang, Akwe, Mejene, Nyame and Ekukole for supporting me and enduring my absence during these years. My family in the US Adelley (my mum), Marion, Agnes, Ivo, Theo, Therion and Jelani who made me feel at home away from home. To my family in Cameroon (Stella, Abwe, Ngalame, Etape, Masango, Hubert and Shirley), I thank you for supporting Martha and the boys, and for your continuous prayers and support during this project. I am also indebted to my friends. I want to express my sincere appreciation to Joe Kujawski and his family for accepting me as a member of their household. Thanks to Miguel and Melissa for weekends spent with them. Thanks to Matt Mitchell and Dana Venditti for always hanging out with me. I also wish to express special gratitude to Martin Cheek for his technical and moral support for so many years. I want to say a special thank you to Bill Konstant for reinvigorating walks through the woods, and his passion for biodiversity conservation. Thanks to Bill for sharing the conservation story and photos of my dad. I also wish to express my appreciation to past and present members of the Gonder Lab: Matt, Paul, Drew, Heidi, Deme, Miguel, Pat, Dana, Hilton, Janina, Bryan, Steve, Ian and Walker. iii I want to sincerely thank the Government of Cameroon, through the Ministry of Forestry and Wildlife (MINFOF), and Ministry of Scientific Research and Innovation (MINRESI) for permission to carry out this research and an enabling research environment. This research was supported by grants from Leakey Foundation, Primate Conservation Inc. and NSF grant to M. K. Gonder. I am grateful to San Diego Zoo Global (SDZG) for supporting this research, and awards via SDZG from USFWS Great Apes Conservation Fund, the Arcus Foundation and the Margot Marsh Biodiversity Foundation. iv Table of contents LIST OF ABBREVIATIONS AND ACRONYMS ………………………………………………………………………………… xii LIST OF TABLES ………………………………………………………………………………………………………………………… xiii LIST OF FIGURES ………………………………………………………………………………………………………………………. xiv ABSTRACT ……………………………………………………………………………………………………………………………….. xvii 1. BACKGROUND AND INTRODUCTION …………………………………………………………………………… 1 1.1. Tropical forest history and biodiversity …………………………………………………………………………. 1 1.2. Chimpanzee distribution, phylogenetics and population history …………………………………… 3 1.3. Habitat diversity and chimpanzees ………………………………………………………………………………… 5 1.4. Chimpanzee socioecology ……………………………………………………………………………………………… 5 1.5. Nigeria-Cameroon chimpanzees ……………………………………………………………………………………. 9 1.6. Study sites ………………………………………………………………………………………………………………….. 11 1.6.1. Ebo forest …………………………………………………………………………………………………………………….. 11 1.6.1.1. Bekob (human-modified rainforest) ….……………………………………………………………… 11 1.6.1.2. Njuma (near pristine rainforest) ………………………………………………………………………. 12 1.6.2. Mbam and Djerem National Park …………………………………………………………………………………. 13 1.6.2.1. Ganga (ecotone) ………………………………………………………………………………………………. 14 1.6.3. Dissertation Structure ………………………………………………………………………………………………….. 14 2. ENVIRONMENTAL AND ECOLOGICAL VARIATION ACROSS THE NIGERIA-CAMEROON CHIMPANZEE RANGE: CLIMATE, FOREST STRUCTURE, FLORISTIC DIVERSITY AND FRUIT PHENOLOGY ..…………………………………………………………………………………………….………………… 19 Abstract …………………………………………………………………………………………………………………………………….19 v 2.1. Introduction …………………………………………………………………………………………………………………. 20 2.2. Methods ………………………………………………………………………………………………………………………. 24 2.2.1. Data collection ……………………………………………………………………………………………………………… 24 2.2.1.1. Climate data ……………………………………………………………………………………………………. 24 2.2.1.2. Botanical inventory ………………………………………………………………………………………….. 25 2.2.1.2.1. Tree and liana enumeration ……………………………………………………………………………… 25 2.2.1.2.2. Terrestrial herbaceous vegetation (THV) .…………………………………………………………. 26 2.2.1.2.3. Botanical identification …………………………………………………………………………………….. 26 2.2.1.3. Potential fleshy fruit species availability ..…………………………………………………………. 26 2.2.1.4. Fruit availability – monthly fruitfall measures …………………………………………………… 27 2.2.2. Principal component analysis for environmental and ecological variables …………………… 27 2.2.3. Data analysis ………………………………………………………………………………………………………………… 27 2.3. Results …………………………………………………………………………………………………………………………. 29 2.3.1. Climate ………………………………………………………………………………………………………………………… 29 2.3.1.1. Temperature and rainfall …………………………………………………………………………………. 29 2.3.2. Botanical enumeration .……………………………………………………………………………………………….. 30 2.3.3. Forest structure …………………………………………………………………………………………………………… 30 2.3.3.1. Diameter at breast height ………………………………………………………………………………… 30 2.3.3.2. Basal area …………………………………………………………………………………………………………. 31 2.3.3.3. Stem density …………………………………………………………………………………………………….. 31 2.3.3.4. Family composition ………………………………………………………………………………………….. 32 2.3.3.5. Species composition ………………………………………………………………………………………… 33