THE REPRODUCTIVE TRAJECTORIES OF BACHELOR GELADAS by David J. Pappano A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Anthropology) in The University of Michigan 2013 Doctoral Committee: Professor Jacinta C. Beehner, Chair Professor Abigail W. Bigham Professor John C. Mitani Professor Elizabeth A. Tibbetts © David J. Pappano All rights reserved 2013 DEDICATION For my parents, Teresa and Donald Pappano For indulging a child’s curiosity in bats, snakes, and other animals described in Golden Guides to Nature. Most parents would have just read fairy tales to their children. And my best friend and partner, Ashley For your patience, kindness, and love in years past and those yet to come. ii ACKNOWLEDGEMENTS Over the past six years, I have been fortunate to have the support of friends, family, colleagues, and funding agencies that have made this dissertation possible. I am grateful for their input at all levels of this endeavor—from conception to completion. My time at the University of Michigan has been among the most formative and memorable experiences of my life, and I hope that many of the friends and colleagues I have met over these past years will continue to be a part of my life in the years to come. This research would not have been possible without the generous support of several government and non-profit funding agencies. A Graduate Research Fellowship from the National Science Foundation and the James Spuhler Fellowship through the Department of Anthropology largely funded my studies at Michigan. I am also grateful to the National Science Foundation for support through a Doctoral Dissertation Improvement Grant. The U.S. Fulbright Program and a Leakey Foundation General Research Grant supported my fieldwork. I also thank the Rackham Graduate School for additional support while writing the final parts of this dissertation. My dissertation chair, Dr. Jacinta Beehner, deserves much praise for my research trajectory. Jacinta has shown me how to develop a project and see it to completion all while balancing her duties as director of the Core Assay Facility, co- director of the University of Michigan Gelada Research Project, and mother to her two small children. I met her and Dr. Thore Bergman the last week of December 2006 at Princeton University. I had recently graduated college and was teaching high school biology in Connecticut. They had just started their jobs at the University of Michigan and iii were preparing for a trip to Ethiopia in January to set up the gelada project. They needed graduate students to study geladas in the formative years of the project, and I was applying to fulfill that need. Against Thore’s warnings that “ice hockey goalies are crazy” and probably her better judgment as well, she took a risk on me as one of their first graduate students. For that, I am grateful. I am also thankful for the guidance of my committee: Dr. John Mitani, Dr. Abigail Bingham, and Dr. Elizabeth Tibbetts. I had the opportunity to teach two classes under John while at the University of Michigan. In this lecture hall, John taught me how to teach through splicing information and humor with thought-provoking questions. In my early years of graduate school, I would attend the Behavioral Ecology Group organized in part by Liz Tibbetts. This seminar provided me with weekly reminders that behavioral ecology did not start and end with geladas (or primates for that matter). To Abby—the only member of my committee that has fewer years at Michigan than I do—I am happy to have had your input in these final steps of my dissertation. Finally, while he was not on my committee, I am indebted to Thore Bergman for giving me the opportunity to conduct research on the geladas of the Simien Mountains. I owe a debt of gratitude to my friends at the University of Michigan and in Ethiopia. My cohort in biological anthropology—Zachary Cofran, Dana Begun, and Caroline VanSickle—have made this journey special. Also, to the newly minted Drs. Noah Snyder-Mackler and Eila Roberts, your culinary skills in Ethiopia and help with analyses at home have kept me sane. To the upstarts of the project—Marcela Benitez, Elizabeth Johnson, Morgan Gustison, and Caitlin Barale—I wish the best of luck in their future projects. Finally, to the camp managers and Ethiopian field workers of the gelada project—Clay Wilton, Julie Jarvey, and Ambaye Fanta—your tireless efforts keeping the campsite organized and functioning were greatly appreciated. iv Of the full-time project assistants, Esheti Jejaw deserves special recognition for his role in this project. I met Esheti in 2008 during my first summer in Ethiopia. I hired Esheti to be a full-time bachelor expert, which required him to find and name bachelors that were associating with the project’s main study band. Because neither of us could speak each other’s native language very well, we accomplished our goals that first summer mostly through miming gelada behavior and speaking a pigeon “Amharenglish”. By the time I returned my second summer, Esheti was using a Palm pilot to record data and had begun to collect ad libitum data on dominance interactions and grooming within bachelor groups. During my long haul of fieldwork in 2010-11, Esheti’s training came full circle. He collected fecal samples for genetic and hormonal data, and was recording focal animal samples everyday. Even though our communication has converged on a mutual understanding of many Amharic-English phrases, I don’t know if I will ever be able to convey just how grateful I am for his help in completing this work. To my mother and father that fostered my love of science at an early age, this is for your countless hours spent with me at the library or watching PBS Nature programs at night. And to my brothers and sister, thank you for understanding in planning holidays and events around my field schedule. Lastly, this thesis is for my best friend and partner of the last seven years, Ashley. She agreed to marry me, now if I can only persuade her to proofread this thesis. v TABLE OF CONTENTS Dedication .......................................................................................................................... ii Acknowledgements ........................................................................................................... iii List of Tables .................................................................................................................... vii List of Figures ................................................................................................................. viii Abstract ............................................................................................................................. ix Chapter One: Introduction ................................................................................................. 1 Chapter Two: Testing extraction and storage parameters for a fecal hormone method . 14 Chapter Three: Demography and social behavior of bachelor geladas living in all-male groups ............................................................................................................................. 32 Chapter Four: Social bonds of bachelor geladas living in all-male groups ..................... 59 Chapter Five: Social ‘predators’ within a multilevel primate society ............................... 88 Chapter Six: Testosterone and the reproductive trajectories of male geladas ............. 109 Chapter Seven: Conclusions ........................................................................................ 138 References .................................................................................................................... 143 vi LIST OF TABLES Table 2.1. A list of experiments conducted under controlled laboratory settings ............ 28 Table 3.1. A description of gelada male age classes ...................................................... 51 Table 3.2. Demography of all-male groups.. ................................................................... 52 Table 3.3. Stable periods of all-male groups. ................................................................. 53 Table 4.1. A summary of mixed models used in social bond analysis. ........................... 81 Table 5.1. Mixed model describing within-unit spacing (‘neighbor’ scan) ..................... 103 Table 5.2. Mixed model describing within-unit spacing (‘unit-spread’ scan) ................. 104 Table 5.3. Mixed model describing between-unit spacing (‘neighbor’ scan) ................. 105 Table 5.4. Mixed model describing between-unit spacing (‘unit-spread’ scan) ............. 106 Table 6.1. A summary of mixed models used in testosterone analysis. ....................... 132 vii LIST OF FIGURES Figure 2.1. Ambient temperature manipulation experiment results. ............................... 29 Figure 2.2. Freeze/thaw experiment results .................................................................... 30 Figure 2.3. Solution manipulation experiment results ..................................................... 31 Figure 3.1. Age class distribution for all bachelor geladas. ............................................. 54 Figure 3.2. Relatedness, age, and coresidence within an all-male group.. .................... 55 Figure 3.3. Elo-ratings of bachelors compared to adult females ..................................... 56 Figure 3.4. Elo-ratings for each bachelor male age class ............................................... 57 Figure 3.5. Comparison