DISTRIBUTION AND LIFE HISTORY OF TWO NON-INDIGENOUS GECKOS Hemidactylus garnotii AND H. mabouia IN SOUTHWEST FLORIDA By GREGG STUART KLOWDEN A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2007 1 To Cathy Olson whose love, friendship, and patience made this possible. 2 ACKNOWLEDGMENTS I would first like to thank the University of Florida Alumni Association, the University of Florida, the Institute of Food and Agricultural Sciences, and the Department of Wildlife Ecology for providing me with a Fellowship, tuition waiver, and Graduate Teaching Assistantship without which my Ph.D. would not have been possible. I would like to thank my committee, Drs. Michael Moulton, Alison Fox, Mark Hostetler, Max Nickerson, and Madan Oli, for their help, generosity, and patience. I am thankful to Dr. Moulton for offering me the opportunity to participate in the organization and teaching of his courses, guiding me through the many intricacies of running a large lecture course, and helping me to become a better teacher. In addition, as the chair of my supervisory committee, Dr. Moulton’s guidance over the years has been critical to my growth as a scientist, ecologist, and writer. His philosophical perspectives on ecology, wildlife conservation, and life are thoughtful, unique, and unmatched as are his humor, good nature, and kindness. His mentoring and friendship will undoubtedly be very influential as I continue to shape my career. I am very thankful to Dr. Hostetler for employing me as his Wildlife Extension Assistant. This position fostered my interest in public outreach and provided me with valuable skills and considerable knowledge that will allow me to continue teaching and encouraging the involvement of the public in conservation issues. Many thanks to Dr. Fox for launching my interest in non-indigenous species through her seminar course and for her very thorough editing, to Dr. Oli for his excellent modeling courses and encouragement, and to Dr. Nickerson for his kindness and being the one person on my committee who understands why someone would scramble around in the middle of the night in pursuit of a lizard. Many thanks also go out to the numerous other people who have helped me during my pursuit of this degree. For financial support I thank the Charlotte Harbor National Estuary Program. For designing the models, writing the software, writing the many brilliant papers, and answering my pestiferous emails I thank Drs. Jim Nichols, Jim Hines, Gary White, Darryl MacKenzie, Roger Pradel, and Rémi Choquet. I also thank Arpat Ozgul and Julien Martin for their consultations. For 3 expediently fulfilling my specimen data requests I thank the numerous museum curators and collection managers. Thanks to Meghan Brennan, IFAS Statistics, for her assistance. For not arresting me for creeping around behind buildings in the middle of the night with a flashlight, I thank the Charlotte and Lee County Police Department. For employing me as his field biologist for the Nile monitor lizard project, his willingness to share his biological knowledge and perspectives on involving the public in conservation, and his friendship I thank Dr. Todd Campbell. For editing I thank Cathy Olson. For providing office space and encouragement, I thank Drs. Eleanor and Bill Marr. I owe a warm thank you to the entire Department of Wildlife Ecology and Conservation faculty for help along the way and for teaching me to be a better scientist. I want to thank the Wildlife Ecology and Conservation staff, past and present, for the many things they have done that made the completion of my Master’s and Ph.D. possible and for their kindness and good humor. Many thanks are owed to Mom and Dad, other family, and friends for their love, encouragement, support, words of wisdom (especially Steve), good humor, and essential musical interludes. Huge thanks for keeping me sane, getting me out of the house to play, and making me laugh are owed to Denny, Darby, Grover, Ury, Gus, Bernie, Zydeco, B2G2, Pedro, and Lola. Lastly I would like to thank the many people I have known and camp counselors and teachers I have had who have fostered my love of animals, the outdoors, and music, and my desire to share my passion and knowledge with others. I am especially thankful to my best friend and wife Cathy Olson. Her willingness to share her knowledge and enthusiasm for natural history and ecology has been essential to my growth as an ecologist. Her kindness, selflessness, and uncompromising morals have been essential to my growth as a person. Her love has been essential to my life. 4 TABLE OF CONTENTS page ACKNOWLEDGMENTS ......................................................................................................... 3 LIST OF TABLES..................................................................................................................... 8 LIST OF FIGURES ................................................................................................................... 11 ABSTRACT............................................................................................................................... 14 CHAPTER 1 INTRODUCTION .............................................................................................................. 16 2 BACKGROUND ................................................................................................................ 19 Distribution......................................................................................................................... 19 Natural History ................................................................................................................... 21 Size .................................................................................................................................. 22 Reproduction ................................................................................................................... 23 Activity............................................................................................................................ 25 Predators.......................................................................................................................... 26 Diet .................................................................................................................................. 27 Dispersal.......................................................................................................................... 28 County Descriptions ........................................................................................................... 28 3 DISTRIBUTION AND RELATIVE ABUNDANCE OF Hemidactylus garnotii AND H. mabouia IN TWO SOUTHWEST FLORIDA COUNTIES .................. 38 Introduction......................................................................................................................... 38 Survey Methods.................................................................................................................. 39 Presurvey Methods.......................................................................................................... 40 Random generation of potential survey points............................................................. 40 Selection of survey buildings ....................................................................................... 41 Data Collection................................................................................................................ 42 Data Analysis...................................................................................................................... 44 Distribution...................................................................................................................... 44 Abundance....................................................................................................................... 44 Within a single season.................................................................................................. 44 Abundance changes over time...................................................................................... 48 Species Interactions......................................................................................................... 49 Number of Geckos Per Building ..................................................................................... 51 Results................................................................................................................................. 51 Charlotte County ............................................................................................................. 51 Single season occupancy estimates .............................................................................. 52 Colonization and extinction.......................................................................................... 52 Species co-occurrence .................................................................................................. 55 5 Number of geckos per building.................................................................................... 56 Lee County ...................................................................................................................... 57 Single year occupancy estimates.................................................................................. 58 Colonization and extinction.........................................................................................