Georgia Southern University Digital Commons@Georgia Southern Electronic Theses and Dissertations Graduate Studies, Jack N. Averitt College of Fall 2014 Tactical Escape Behavior and Performance of a Small Sceloporine Lizard in Two High Risk Habitats Seth Parker Follow this and additional works at: https://digitalcommons.georgiasouthern.edu/etd Part of the Behavior and Ethology Commons, Evolution Commons, Integrative Biology Commons, and the Population Biology Commons Recommended Citation Parker, Seth (2014). Tactical Escape Behavior and Performance of a Small Sceloporine Lizard in Two High Risk Habitats. Electronic Theses & Dissertations, Georgia Southern University. This thesis (open access) is brought to you for free and open access by the Graduate Studies, Jack N. Averitt College of at Digital Commons@Georgia Southern. It has been accepted for inclusion in Electronic Theses and Dissertations by an authorized administrator of Digital Commons@Georgia Southern. For more information, please contact [email protected]. TACTICAL ESCAPE BEHAVIOR AND PERFORMANCE OF A SMALL SCELOPORINE LIZARD IN TWO HIGH RISK HABITATS by SETH E. PARKER (Under the direction of Lance D. McBrayer) ABSTRACT The negotiation of uneven and complex terrain has implications for many small terrestrial vertebrates. Variation in the running surface due to obstacles like woody debris or vegetation can alter escape paths and running performance. Additionally, these microhabitat features can influence behavioral tactics in complex environments. The ability to negotiate physical barriers in dense environments likely influences survivorship through important ecological tasks, such as finding mates, foraging, and evading predators. The Florida scrub lizard (Sceloporus woodi) is a small, rare species endemic to two distinct and structurally complex environments in Florida, i.e. sand-pine scrub and longleaf pine-wiregrass sand-hills. The differing microhabitats of scrub and longleaf pine factor into the distribution and density of lizard populations throughout the Ocala National Forest in Florida. Understanding strategies to avoid predation between these two habitats can give insight into the likelihood of population persistence, and whether one habitat may harbor a greater lizard density. Additionally, the underlying performance impacts from habitat structure (e.g. multiple obstacles) can shed light on any unique abilities in small terrestrial lizard species. In the first chapter I focus on how multiple obstacles influence running behavior and locomotor posture. Bipedal running was more efficient for crossing obstacles via faster sprint speeds and minimal foot contact with an obstacle. The second chapter investigates the populations of scrub lizards in both the scrub and longleaf habitats. I determine how risk 1 behaviors vary between habitats, and quantify the detectability and condition of lizards in each. Longleaf pine lizards had greater flight and detection distance than in sand pine scrub. Males showed greater risk aversion and were easier to detect than females in both habitats, indicating that they may be more sensitive to predation when conspicuously occupying open areas. Overall this study reveals areas in need of consideration with habitat management in the Ocala National Forest. Studies such as this help provide a mechanistic understanding of dispersal ability, habitat avoidance, and behavioral flexibility in this rare species, which may be useful to land managers and conservation biologists. INDEX WORDS: Scrub lizard, Sceloporus woodi, Bipedal, Quadrupedal, Obstacles, Velocity, Flight distance, Microhabitat, Refuge 2 TACTICAL ESCAPE BEHAVIOR AND PERFORMANCE OF A SMALL SCELOPORINE LIZARD IN TWO HIGH RISK HABITATS by Seth Elias Parker Bachelor of Science, Appalachian State University, 2011 Master of Science, Georgia Southern University, 2014 A Thesis Submitted to the Graduate Faculty of Georgia Southern University in Partial Fulfillment of the Requirements for the Degree MASTER OF SCIENCE STATESBORO, GEORGIA 2014 3 © 2014 SETH ELIAS PARKER All Rights Reserved 4 TACTICAL ESCAPE BEHAVIOR AND PERFORMANCE OF A SMALL SCELOPORINE LIZARD IN TWO HIGH RISK HABITATS by SETH E. PARKER Major Professor: Dr. Lance D. McBrayer Committee: Dr. David C. Rostal Dr. J. Michelle Cawthorn Electronic Version Approved: Fall 2014 5 ACKNOWLEDGMENTS While I endured the strenuous, yet enjoyable, task of field and lab work mostly alone, this project would not have been attainable without assistance from several friends and colleagues. I would like to thank R. Anderson, J. Sergi, M.D.D. Kaunert and K. Hanley for assistance in the field capturing lizards, and my committee members, D. Rostal and M. Cawthorn. I am also grateful to J. Self and C. Collins for their invaluable MATLAB insight, A. Tinney for lab assistance, C.R. Chandler for his statistical genius, and S. Harp for assisting in racetrack construction. Research in Ocala National Forest was conducted under protocol with the Institutional Animal Care and Use Committee (IACUC permit # I12006) and permission from the U.S. Forest Service (USFS permit #SEM540). Funding for this research was provided by a Graduate Student Professional Development grant from the College of Graduate Studies. Finally, a debt of gratitude is owed to old man L. McBrayer for knowingly sending his graduate student through the turmoil that accompanies a field season. 6 TABLE OF CONTENTS Page ACKNOWLEDGMENTS .............................................................................................................. 6 LIST OF TABLES .......................................................................................................................... 8 LIST OF FIGURES ........................................................................................................................ 9 CHAPTER 1: THE EFFECTS OF MULTIPLE OBSTACLES ON THE LOCOMOTOR BEHAVIOR AND PERFORMANCE OF A TERRESTRIAL LIZARD (SCELOPORUS WOODI) ........................................................................................................................................ 10 ABSTRACT .............................................................................................................................. 10 INTRODUCTION ..................................................................................................................... 11 METHODS................................................................................................................................ 18 RESULTS.................................................................................................................................. 22 DISCUSSION ........................................................................................................................... 25 REFERENCES .......................................................................................................................... 33 TABLES AND FIGURES ......................................................................................................... 38 CHAPTER 2: VARIATION IN SCRUB LIZARD (SCELOPORUS WOODI) POPULATIONS BETWEEN TWO HABITAT TYPES IN OCALA NATIONAL FOREST, FL ......................... 44 ABSTRACT .............................................................................................................................. 44 INTRODUCTION ..................................................................................................................... 45 METHODS................................................................................................................................ 49 RESULTS.................................................................................................................................. 51 DISCUSSION ........................................................................................................................... 52 REFERENCES .......................................................................................................................... 58 TABLES AND FIGURES ......................................................................................................... 62 APPENDICES .............................................................................................................................. 66 APPENDIX A: OVERHEAD VIEW OF THE RACETRACK ................................................. 66 APPENDIX B: VIEW FROM THE STARTING POSITION OF THE RACETRACK ........... 67 APPENDIX C: SCELOPORUS WOODI WITH KINEMATIC LANDMARKS ...................... 68 APPENDIX D: EXPERIMENTAL DESIGN USED IN CHAPTER 1 ..................................... 69 APPENDIX E: EXPERIMENTAL DESIGN USED IN CHAPTER 2 ...................................... 70 7 LIST OF TABLES Page Table 1.1: Raw data of locomotor performance and behavior in S. woodi ....................................38 Table 1.2: Raw kinematic data for bipedal and quadrupedal running in S. woodi ........................39 Table 2.1: Risk behavior and detectability between habitats and adult lizards .............................62 Table 2.2: Summary of refuge type where lizards were captured among each habitat stand ........63 8 LIST OF FIGURES Page Figure 1.1: Mean velocity (m/sec) ± S.E.M. by obstacle group and obstacle crossing behavior for total velocity (postures combined), bipedal, and quadrupedal posture ..........................................40 Figure 1.2: Frequency of obstacle crossing behavior and posture without an obstacle, with obstacle (1-3), and within each obstacle