Department of Environmental Studies DISSERTATION COMMITTEE PAGE The undersigned have examined the dissertation entitled: DISPERSION OF LARGE-SEEDED TREE SPECIES BY TWO FOREST PRIMATES: PRIMATE SEED HANDLING, MICROHABITAT VARIABILITY, AND POST-DISPERSAL SEED FATE presented by Nicole D. Gross-Camp candidate for the degree of Doctor of Philosophy and hereby certify that it is accepted*. Committee chair name: Beth A. Kaplin, Ph.D. Title/Affiliation: Core Faculty/ AUNE, Department of Environmental Studies Committee member name: Peter Palmiotto, D. F. Title/Affiliation: Core Faculty/ AUNE, Department of Environmental Studies Committee member name: Joanna E. Lambert, Ph.D. Title/Affiliation: Associate Professor/ University of WI, Madison, Department of Anthropology & Zoology Defense Date: 12th December 2008 *Signatures are on file with the Registrar’s Office at Antioch University New England. DISPERSION OF LARGE-SEEDED TREE SPECIES BY TWO FOREST PRIMATES: PRIMATE SEED HANDLING, MICROHABITAT VARIABILITY, AND POST-DISPERSAL SEED FATE by Nicole D. Gross-Camp A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Environmental Studies) at ANTIOCH UNIVERSITY NEW ENGLAND – KEENE, NH USA 2008 © Copyright by Nicole D. Gross-Camp 2009 All rights reserved Innocent with Senna (top left), Theoneste and his daughter (top right) and Donati and Felicee (bottom) Martin and Senna (top) Martin, Cesar, Fidele with Senna, and Nicole (bottom) Abrahim, Nicole and Gratien in pine buffer near Banda (top) Stella, Beth and Senna in Butare (bottom) i Dedication The efforts of many Rwandans made my dissertation possible and for this I am deeply grateful. My life and graduate research was enriched by our interactions and I am humbled by their strength and tenacity. They have given me the gift of perspective and taught me that generosity extends far beyond the material world. Murakoze cyane cyane. Abrahim Ngiruwonsanga Fidèle Muhayeyezu Theonèste Nzabonimana Innocent Semahoro Martin Mudaheranwa Donat Murwanashyaka Gratien Gatorano I also dedicate my dissertation to Anastase Benimana who taught me so much about the forest and the chimpanzees. His delightful sense of humor warmed my heart on many a cold day in the forest. May he be able to return to his work with the chimpanzees someday. ii Acknowledgements While each chapter contains its own acknowledgements section there are many, many others whose contributions to the completion of my dissertation I would like to recognize. Foremost I thank my advisor and committee chair, Beth A. Kaplin. The guidance she has provided me over the past nine years and belief in my ability to succeed has been critical to my growth as a scholar and professional. My thanks to her for the opportunities that she has provided me and support in the field are impossible to express. She has deepened my ability to think critically, infected me with her passion for Rwanda, taught me to be patient and persistent, and that, above all, it is the quality of your work that defines you. In addition to Beth, my other committee members, Peter Palmiotto and Joanna Lambert nurtured my formation into a scholar. Peter’s expertise in forest ecosystems kept me to task ensuring that my dissertation adequately addressed the plant perspective. His critical insights into my work helped to expand my perspectives and ability to discuss my work with scientists from varying backgrounds. Joanna’s work was an inspiration to the formation of my dissertation proposal. She gave me the gift of the unknown providing fodder for what became my doctoral research. Joanna, too, has helped me grow as a scholar. I am deeply indebted to all of my committee members for their diligence in reading through my dissertation and providing me with critical feedback. Many individuals in Rwanda where my research was based welcomed me (and my family) into their homes and provided a solid foundation from which to conduct my research. I am grateful for the friendship and professional support of Michel Masozera, Ian Munanura, Nsengi Barakabuye, Felix Mulindahabi, and Francois Bizimungu. My iii cook and dear friend, Martin Nsengumuremyi, provided countless warm and delicious meals, strong tea, and endless evenings of fascinating conversation and laughter. I thank Emmanuel whose bright face greeted us each morning and provided us with fresh clean water. I thank Evanys Nyinagwaneza for her sweet and generous care for my family and me. I am particularly grateful to Claver Ntoyinkima, Eraste Nzakiwanayo, Jean-Baptiste Gakima, Martin Sindikubwabo, Ferdinand Ngayabahiga, Gratien Ndiramiye, and Gratien whose friendship and interest in my work was sincerely appreciated. I wish to thank the many friends, faculty and colleagues at Antioch University New England who have supported me through this endeavor including Susan Weller, Sarah Bockus, Kay Delanoy, Jon Atwood, Thomas Webler, Kelly Biedenweg, Luanne Johnson, Nora Traviss, and Tharcisse Ukizintambara. Michael Sutherland who helped me beyond the call of duty to make sense of my data. His candor, fun-loving nature, and uncanny ability to explain statistics made me feel at ease and confident in my ability to successfully analyze and make sense of my data. Several friends have played an important role in my mental sanity. Anne McBride and Rich Popovic provided countless letters, newspaper clippings, comedic relief and, of course, chocolate. Their love warmed my heart and kept me going during times of doubt. Janice Simsohn, my childhood friend, who was always enthusiastic about my work and whose effort to connect me with other like-minded folks is sincerely appreciated. Sylvia Torti and Donald Feener (many years ago in the town of Epulu) nurtured my interest in pursuing a doctorate selflessly taking me under their wings and introducing me to the larger community of tropical ecology and academia. Kate Kruckemeyer and Martha iv Spencer provided immense support as I entered the world of motherhood and helped me keep afloat as I re-learned how to navigate academia with children. The support of my extended family, Sue and Ian Camp, Jo, Paul & George Stephens, and Angela, Andy, Ellie, Hannah, and Kate Graham, has been a great respite from my research. Their love and generosity carried me through the rough patches and gave me the strength to continue. My parents, Steve and Carol Gross, and brother, Aaron Gross, are at the core of my being. The passion and intention with which they pursue life has been a continual source of inspiration to me. Their patience, support, and utterly unconditional love is a gift that I am forever grateful. Each of them has contributed to the development and completion of this doctorate through their unique personalities - my mother’s insightful and artistic nature brought beauty to my work and helped to ground me as I navigated life in a new culture, my father’s bizarre sense of humor and ability to deal with difficult issues taught me the art of negotiation, and my brother, whose dedication to a compassionate life has inspired me to move beyond the degree. My dear husband Simon Camp whose devotion was immediate, unwavering, and absolutely essential on my path to receive my doctorate. I am deeply indebted to him for his flexibility and willingness to live where I needed to and belief in my ability to succeed. He is a remarkable person and committed partner, friend, and father; his love is an inspiration. Finally I thank my children, Senna and Rowan Camp, whose love and lives has enriched my own beyond words. They inspire me to make the world a better place, to question the familiar, to laugh at myself, and love like there is no tomorrow. v Abstract I describe the relative effectiveness of two primates in dispersing large-seeded tree seeds (> 0.5 cm) in the Nyungwe National Park (NNP), Rwanda. My objectives are three-fold: (1) to describe the relative effectiveness of primates in dispersing the seeds of five large- seeded tree species, (2) to evaluate the influence of primate seed-handling method on seed fate, and (3) to determine the influence of deposition site on seed fate. I employed focal tree observations, day-follows of habituated primate groups, in situ monitoring of primate-dispersed seeds, and experimental plots to achieve these objectives. Data were collected over the course of one year (April 2006 – April 2007). Frugivore assemblages dispersed the seeds of four of the five focal tree species. Chimpanzees and cercopithecines spent the most time in trees and had the largest group size. Large-bodied birds (LB) and chimpanzees dispersed the highest number of seeds per minute. LB and cercopithecines potentially disperse the greatest number of seeds for Ekebergia capensis, and chimpanzees for Syzygium guineense. My study highlights the complexities of determining a disperser’s effectiveness and suggests that large-bodied birds and primates are relatively important dispersers of large-seeded trees. Primates deposit seeds most often in open forest where seeds experience the highest establishment. In addition primates deposit seeds in five habitats that are likely dispersal- limited suggesting that primates contribute to the regeneration processes of otherwise dispersal-limited areas. My results suggest that the former emphasis of seed dispersal vi studies on defecations is not representative and should be expanded to include orally- discarded seeds. Furthermore my study highlights that primates do not deposit seeds randomly and that the characteristics of the deposition site are a reflection of primate seed handling. I found no relationship between the top five fruiting tree species found in chimpanzee feces and fruit availability suggesting that chimpanzees do not choose fruits solely based on their availability. In contrast the wadged fruits of Syzygium guineense are positively correlated to fruit availability. A closer examination of the relationship between chimpanzees and S. guineense may provide insight into potential repercussions on the regeneration of S. guineense if the chimpanzee were to be extirpated.