SOCIAL ORGANIZATION OF A SPECIES OF SINGING MOUSE, Scotinomys xerampelinus By DIMITRI VINCENT BLONDEL A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2006 Copyright 2006 by Dimitri Vincent Blondel This thesis is dedicated to my parents, Pierre and Linda, who have supported me in all of my dreams and ambitions throughout my life. ACKNOWLEDGMENTS I would like to thank my committee members, Dr. Steven M. Phelps, Dr. H. Jane Brockmann, and Dr. Lyn Branch, for all of their help with this project. Dr. Brockmann and Dr. Phelps were co-chairs of my committee, and provided extremely valuable advice and support. Dr. Phelps introduced me to singing mice, the wonderful country of Panama, and ceviche, and provided generous funding and equipment support. Jorge Pino, our research assistant in the field, contributed greatly to this project. Dr. Rafael Samudio provided much appreciated logistical support with permits and other field arrangements in Panama. Thanks go to Dr. Jerry Wolff for providing radio-tracking training in Memphis, and for advice and discussion. Thanks go to Dr. Alex Ophir for help with statistics and graphs. Thanks go to Dr. Donald Dewsbury for sharing his knowledge of Scotinomys. The graduate students and post-doctoral associates in the Department of Zoology provided valued input; this includes Polly Campbell, Ondi Crino, Billy Gunnels, Joanna Matos, Toshi Okuyama, and many others. Thanks go to Dr. Mel Sunquist and Dr. Stephen Coates for providing my initial radio-tracking and live-trapping training in their field techniques course at the Ordway Preserve. Rebecca Kimball’s behavioral ecology course was very helpful, and gave me the opportunity to write a review on the concepts and measurement of home range and territoriality, much of which was included in this thesis. Thanks go to the Autoridad Nacional Del Ambiente of Panama and the Panamanian government for making our field research possible. Thanks go to Lionel, Roberto, Hartmann, Domingo, Antonio and the rest of the rangers and staff iv at Parque Internacional La Amistad in Las Nubes, Cerro Punta, Panama for allowing us to live and work at the field site, and for enlivening our stay. Thanks go to George Babos and Ratibor Hartmann for letting us perform research on their land. Thanks go to Christel Eichner, Vilma Fernandez, and the Ortiz family (Eduardo, Bertha, Vanessa, Mayanin, Edward and David) for providing assistance in the field and for their generous hospitality. Thanks go to all the folks at the ASAELA restaurant for providing hearty Panamanian meals to sustain our fieldwork over two summers. Thanks go to the Department of Zoology at the University of Florida and the Brian Riewald Memorial Fund for funding. Thanks go to the University of Florida Animal Care Services people for all their help with the colony, particularly Sherry Scruggs and Leonard MacDonald. Thanks go to the Department of Zoology staff, Karen Pallone and Vitrell Sherif, for helping me to navigate through the occasional labyrinths of paperwork. Thanks go to the army of Phelps lab volunteers who have helped maintain the colony of singing mice over the years, including Ashley Bates, Jennifer Dark, Ally De Padua, Shainel Eans, DeAnne Fanta, Crystal Jeter, Uy Le, Missy Moorman, Stavros Moysidis, Katie O’Mahoney, Molly Phillips, Matt Smukall, Brittany Spall, Cuc Tran, Quiana Wilkerson, Daphna Yasova, and David Zheng. Thanks go to my brother Emile who hosted me on a much- needed break in Paris mid-way through my Master’s studies. Thanks go to my parents, Pierre and Linda Blondel, for all their support. Finally, thanks go to my partner, Jennifer Dark, for helping in so many ways, not the least of which was enthusiastically reading many of my various manuscript revisions. v TABLE OF CONTENTS page ACKNOWLEDGMENTS ................................................................................................. iv LIST OF TABLES........................................................................................................... viii LIST OF FIGURES ........................................................................................................... ix ABSTRACT....................................................................................................................... xi CHAPTER 1 INTRODUCTION ........................................................................................................1 The Singing Mouse.......................................................................................................1 Species Background......................................................................................................2 Territoriality..................................................................................................................3 Demonstrating Territoriality in Small Mammals .........................................................4 Mating System..............................................................................................................7 Theoretical Bases for Mating System Correlates ..................................................7 Scotinomys xerampelinus Mating System...........................................................11 2 HOME RANGE, TERRITORIALITY, AND MATING SYSTEM IN A NATURAL POPULATION OF Scotinomys xerampelinus IN PANAMA...............16 Introduction.................................................................................................................16 Species Background ............................................................................................16 Home Range ........................................................................................................17 Territoriality ........................................................................................................19 Space Use Patterns ..............................................................................................21 Space Use Hypotheses and Predictions...............................................................22 Mating System Categories...................................................................................22 Mating System of Scotinomys xerampelinus.......................................................24 Mating System Hypotheses for S. xerampelinus.................................................25 Methods ......................................................................................................................26 Fieldwork.............................................................................................................26 Data Analysis.......................................................................................................33 Results.........................................................................................................................37 Discussion...................................................................................................................41 Territoriality ........................................................................................................41 vi Mating System.....................................................................................................43 Conclusion...........................................................................................................44 3 AGONISTIC BEHAVIOR IN THE SINGING MOUSE: A RESIDENT- INTRUDER STUDY..................................................................................................58 Introduction.................................................................................................................58 Methods ......................................................................................................................60 Experimental Design ...........................................................................................60 Procedure.............................................................................................................61 Subjects................................................................................................................64 Data Analysis.......................................................................................................65 Results.........................................................................................................................67 Aggressive Behavior ...........................................................................................67 Out-of-Sight Behavior.........................................................................................70 Discussion...................................................................................................................73 Defense Behavior ................................................................................................74 Out-of-Sight Behavior.........................................................................................77 Site-Specific Dominance.....................................................................................79 The Scotinomys xerampelinus Social System .....................................................81 4 SUMMARY..............................................................................................................102 Space Use..................................................................................................................102 Mating System..........................................................................................................103