Copyright by Joyce Ann Parga 2006 The Dissertation Committee for Joyce Ann Parga certifies that this is the approved version of the following dissertation: Sexual Selection in the Ring-tailed Lemur (Lemur catta): Female Choice, Male Mating Strategies, and Male Mating Success in a Female Dominant Primate Committee: Deborah J. Overdorff, Supervisor Claud A. Bramblett Lisa Gould Rebecca J. Lewis Liza J. Shapiro Sexual Selection in the Ring-tailed Lemur (Lemur catta): Female Choice, Male Mating Strategies, and Male Mating Success in a Female Dominant Primate by Joyce Ann Parga, B.S.; M.A. Dissertation Presented to the Faculty of the Graduate School of The University of Texas at Austin in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy The University of Texas at Austin December, 2006 Dedication To my grandfather, Santiago Parga Acknowledgements I would first like to thank the St. Catherines Island Foundation, without whose cooperation this research would not have been possible. The SCI Foundation graciously provided housing and transportation throughout the course of this research. Their aid is gratefully acknowledged, as is the permission to conduct research on the island that I was granted by the late President Frank Larkin and the Foundation board. The Larkin and Smith families are also gratefully acknowledged. SCI Superintendent Royce Hayes is thanked for his facilitation of all aspects of the field research, for his hospitality, friendliness, and overall accessibility - whether I was on or off the island. The Wildlife Conservation Society (WCS) is also an organization whose help is gratefully acknowledged. In particular, Colleen McCann and Jim Doherty of the WCS deserve thanks. The WCS employees of the Wildlife Survival Center on St. Catherines Island always treated me like family, even though my stays were always temporary. The help of Senior Zoologist Robert Lessnau was especially crucial to the completion of this project. Bob, your willingness to share your years of experience with the lemurs of St. Catherines (as well as your passenger seat for numerous car rides, not to mention attic space for cumbersome field gear!) will be forever remembered. Jeff Spratt, past Curator v of the Wildlife Survival Center is also thanked for his steadfast support of my research, as is Terry Norton, an excellent veterinarian who also understands and values research immensely. Jennifer Savage, primate keeper, also provided valuable information on the lemurs when I was away from particular groups, or was away from the island. Several WCS interns made life infinitely easier by occasionally aiding in my research and providing friendship during my stays on the island, and I thank them all, especially Kelly Guinn, Del Hurst, and Tyann Marsh. I thank my dissertation committee for their guidance: Deborah Overdorff (chair and my major advisor), Claud Bramblett, Lisa Gould, Becca Lewis, and Liza Shapiro. Throughout my graduate program and stages of writing, you all were a source of continued support, knowledge and insight. Claud, always a repository of wisdom, anecdotes and advice, I thank you for all of the stories (human and non-human primate alike!) that I will be able to share with my own students to enhance their understanding of this curious and unique mammalian order. Lisa, the first time we met, you said that I could ask you anything at all about ring-tailed lemurs, and you have been unselfishly sharing your knowledge ever since! Thank you for helping me to improve my work, and for providing me with a perspective from your years of research in Madagascar. Becca, it is a pleasure to share my work with you – your constructive criticism and positive attitude provides the perfect atmosphere for academic growth. Liza, I thank you for lending your outside perspective to my research and writing, which, without fail, has allowed me to strengthen my work. I also thank you for your indispensable advice about all things academic over the years. Finally, to my advisor Deborah, I thank you for vi giving me the opportunity to enter the world of primatology, and for being open-minded enough to let me do things my way while also solidly providing direction and a guiding hand at critical junctures. You always maintained a positive outlook that I found infectious, and your confidence in me has never flagged. Thank you. Also deserving of thanks are several professors who have played a role in shaping my academic development and that of my research. Two mentors I had as an undergraduate at the University of California at Irvine, Nancy Burley and George Hunt, Jr., both helped to foster my interest in behavioral ecology, and provided me with my first glimpse into academia. Early on they provided me with a broad taxonomic perspective for which I will always be grateful. Throughout my years of graduate school, Anne Mertl-Milhollen, Michelle Sauther, Bob Sussman, and Linda Taylor were never too busy to talk to me about lemur behavior and related topics, and occasionally provided a sounding board for my ideas – for this I will always be grateful. I also thank my past and present fellow students at the University of Texas at Austin, a group of people whose academic talent is equally matched by their capacity for friendship and collegiality. To my fellow academic ‘sibs’ Laura Alport, Chris Grassi, Steig Johnson, and Stacey Tecot - you were always available to give advice, and lend an ear to the “catta” side of things. The friendship of Angela Palmer and Summer Bowman were integral in making me feel at home at UT-Austin, especially in my early years of graduate school when Texas didn’t yet feel like home. To my fellow cohort members Katherine Whitcome and Murat Maga: Kath, thank you for your candid and ultra- vii supportive nature, and for our dissertation support meetings. You were always there with a kind and encouraging word. My dissertation writing period would not have been quite the same without your mutual support. Murat, thanks for sharing your CT scanning skills, I enjoyed the collaboration immensely. To all other past and present UT students too numerous to name who I have had the pleasure of knowing - you have all helped to create fond memories of my time at UT. To my field assistants Layla Coleman, Amy Henry, Shawna Meyers, Kristen Parks, and Rachael Smith: thank you for your giving up a little of your lives to accompany me to “The Island”. I will always be grateful for your help and friendship in the field, and feel extraordinarily fortunate that I found such dependable assistants. I am glad that I was able to share with you the unique place that St. Catherines Island is, and give you a window into the lives of the ring-tailed lemurs who live there. Last but most certainly not least, I thank Serv J. Lozano for many things – especially for his steadfast determination to never let my confidence or productivity wane. I thank you for choosing to use your time and energies to help me to do what I love, and for repeatedly accompanying me in my yearly migratory trek to my field site. This road has been so much more enjoyable with you to share my ups and downs. No acknowledgement would be complete without a word of thanks to the subjects that make the research possible. The ring-tailed lemurs of St. Catherines Island have taught me more than I could have ever expected. I hope I have done my part to highlight some viii of the most intimate portions of their lives to help reveal the amazing but subtle complexity of their social relationships and reproductive behavior. Funding for this research was provided by two Graduate Research Fellowships from the College of Liberal Arts at the University of Texas at Austin. I was supported throughout its research and writing by a National Science Foundation Graduate Pre-Doctoral Fellowship, a Bruton Fellowship from the University of Texas at Austin, a University Continuing Tuition Fellowship from the University of Texas at Austin, and by a Ford Foundation Dissertation Fellowship. ix Sexual Selection in the Ring-tailed Lemur (Lemur catta): Female Choice, Male Mating Strategies, and Male Mating Success in a Female Dominant Primate Publication No._____________ Joyce Ann Parga, Ph.D. The University of Texas at Austin, 2006 Supervisor: Deborah J. Overdorff Where male-male mating competition is intense, males are frequently larger than females, or have weaponry (e.g. enlarged canines) that females lack. Male dominance over females is often thought to be a by-product of selection for superior size and aggression. Paradoxically, some Malagasy primates show aggressive male-male competition over access to mates, yet lack sexual dimorphism in body size and dentition, and exhibit female dominance over males. This study’s purpose was to investigate female choice and male mating strategies in one such species, the ring-tailed lemur (Lemur catta), to compare the success of physically combative male mating strategies versus alternative non-combative strategies (i.e. sneak copulations). Data were collected across five breeding seasons (2000-2004) on St. Catherines Island, USA, on a provisioned free-ranging L. catta population. Four distinct L. catta groups were studied, two per breeding season, each group having 4-8 females and 2-4 non-natal males. The most commonly used male mating tactics were those that depended on physical contest x competition among males. Alpha males often used their dominance status to gain first access to an estrus female, while non-alpha males frequently employed the use of dominance rank reversals as a mating strategy, which required aggressive challenges of more dominant males. Sneak and evasive copulations were also used, though much less often.