BURROWS OF SEMI-FOSSORIAL VERTEBRATES IN UPLAND COMMUNITIES OF CENTRAL FLORIDA: THEIR ARCHITECTURE, DISPERSION AND ECOLOGICAL CONSEQUENCES By ALTON EMORY KINLAW 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 2006 1 To my daughter Skye Gabrielle Kinlaw, who has accomplished more in her short 11 years than most adults do in a lifetime. 2 ACKNOWLEDGMENTS I owe a major professional and personal debt to my chair, Michael Moulton for his guidance. In particular, at a time when I was discouraged due to health and financial reasons, he encouraged me to stay the course. Because of his quantitative background in orthithology, herpetology, and mammalogy, he has a unique intellectual perspective about vertebrate ecology and always challenged me to ask the right questions. Additionally, he provided me with a balance, Sherman live traps, and microscope. My co-chair, Dick Franz, shared his comprehensive knowledge about natural history of Florida fauna, and served as project director of the Avon Park project issues. He encouraged me to write the Avon vertebrate diversity chapter and carefully critiqued all of my papers. My research is based upon the theoretical background developed by Jim Nichols and his colleagues at Patuxent Wildlife Research Center. Jerry Butler, UF Department of Entomology and Nematology, provided sticky traps and “Tick Sucker” vacuums, reprints, and freely shared his extensive knowledge of insect fauna that use tortoise burrows. Ken Portier graciously stayed on my committee after leaving UF for a position in Atlanta, and allowed me to visit him with my questions. Katie Sieving always provided thoughtful advice. Willie Harris, UF Department of Soil Science was the visionary who encouraged me to think of the subsurface soil layer as a three dimensional life environment, and this ultimately led me to conduct the ground penetrating radar investigations. Sam Jones provided equipment and a truck and helped in many ways during the early part of my field work. George Tanner loaned me an ORV during the early part of my field work. 3 Thanks are extended to W.R.J. Dean, Joel Brown, and Fenton Kay for critically reviewing the material in chapter 2. The Avon Park research was supported by the Natural Resources Flight of the Avon Park Air Force Bombing Range (Project RWO-169). Pat Walsh assisted with many operational aspects of the field work, and Peg Margosian provided valuable GIS support. I thank the Florida Cooperative Wildlife Research Unit for its assistance in managing the funds used for the Avon Park research. For the gopher tortoise chapter, I thank the members of the survey team: Dick Franz (Director), Rex Kinlaw, Kenny Koehler, Richard Bubba Owen, Chris O’Brien, David Maehr, and Lora Smith. For the armadillo chapter, a special debt of gratitude is owed Gary White, who both provided the SURVIV code he used in the White and Bennetts (1996) paper and corrected my SURVIV code. C. Krebs answered questions about his computer program. Marinela Capanu, Department of Statistics, IFAS, University of Florida, provided statistical support. Jennifer Brown shared information about her possum simulation study in New Zealand. James Layne reviewed an early draft of the manuscript. C. Krebs answered questions about his computer program. Colleen McDonough clarified plot data from her north Florida study. For the burrow architecture chapter, Jerry Fensch of Florida Environmental allowed me to foam tortoise burrows in a tortoise relocation project near Clermont, and made arrangements for a backhoe to dig the burrows up. Larry Conyers, University of Denver, and Mark Grasmusen, University of Miami, brought their ground penetrating radar equipment to my study area for the radar survey. 4 For the Avon Park vertebrate diversity chapter, Dick Franz, Bubba Owen, and Chris O’Brien identified many of the specimens. Dick Franz and Bubba Owen provided slides and clarified aspects of the sampling process. Kenny Krysko provided access to his unpublished range maps of herpetofauna of Florida. For other aspects of my research, the following biologists (and their affiliation) provided access to the following study areas: Anne Malatesta (Lake Wales Ridge State Forest); Boyd Blihovde and Bubba Owen (Wekiwa Springs State Park), Carlton Hall (Dynamac Corporation, Kennedy Space Center) and Marc Epstein (Merritt Island National Wildlife Refuge), the natural resources staff at Ocala National Forest, especially Janet Henshee. Bob Giguere, Executive Producer of WMFE Channel 24 in Orlando, filmed my project as part of his documentary, “Wekiwa-Legacy or Lost?” Herb Kalmbacker (IFAS) loaned me seed shakers. Dave Almquist, Entomology, shared his knowledge regarding beatle taxonomy and his “burrow facade trap.” Louis Kelemen of Zelwin Farms built a small “tick sucker” vacuum for me, and Bill Kelly provided me with many sources for the many supplies I needed. Paul Schumacher of Hughes Supply, Inc of Orlando not only provided 8 and 10 in PVC pipe (for pitfall traps) gratis, but spent time cutting sections for me. My wife Monnie, while not a biologist, had an uncanny sense for what would and would not work with my traps. Her background as an agricultural nurse proved to be helpful in uncountable ways, especially with my history of Lyme disease. My daughter Skye was a very colorful and chatty field assistant on several occasions, and enthralled everyone with her comments about “getting dirty as a pig.” 5 TABLE OF CONTENTS page ACKNOWLEDGEMENTS…………………………………………………………... 3 LIST OF TABLES…………………………………………………………………… 9 LIST OF FIGURES………………………………………………………………….. 11 ABSTRACT………………………………………………………………………….. 14 CHAPTER 1 INTRODUCTION………………………………………………………………. 16 2 A REVIEW OF BURROWING BY SEMI-FOSSORIAL VERTEBRATES IN ARID ENVIRONMENTS ............................................... 19 Introduction: Fauna of Arid Regions …………………………………… 19 Methods…………………………………………………………………… 20 Results and Discussion…………………………………………………… 21 Natural History…………………………………………………… 21 Functional Ecology, Burrow Architecture, 25 and Burrowing Behavior…….……………………………… Classical Ecological Issues………………………………………… 31 Animals as Engineers and Resulting Impacts… 33 Geomorphology…………………………………………………… 36 Pedological Effects of Burrowing on The Soil…………………… 37 Pedological Effects of the Soil Type on Architecture and Species Distribution…………………………………… 38 Vegetation Effects………………………………………………… 39 Animal Community Ecology……………………………………… 39 Future Research and a Conceptual Model ………………..……………… 41 3 SAMPLING APPROACHES TO ESTIMATE DENSITY OF GOPHER TORTOISES (Gopherus polyphemus) IN CENTRAL FLORIDA …….……… 46 Limitations of Current Gopher Tortoise Burrow Census Methods……….. 46 Materials and Methods……………………………………………………. 50 Results…………………………………………………………………….. 55 Discussion………………………………………………………………… 57 6 4 BURROW DISPERSION OF ARMADILLOS (Dasypus novemcientus) AT AVON PARK AIR FORCE RANGE, FLORIDA ……………………………………………………………………..... 70 Introduction: Armadillo Life History…………………………………........ 70 Study Area…………………………………………………………………. 72 Methods………………………………………………………………......... 72 Results……………………………………………………………………… 76 Discussion………………………………………………………………… 77 5 ARCHITECTURE OF GOPHER TORTOISE BURROWS DETERMINED BY 2D GROUND PENETRATING RADAR………………… 86 Introduction: Gopher Tortoise Burrows…………………………………..... 86 Ground Penetrating Radar Methodology………………………………… 87 Field Site Description and Burrow Selection……………………………… 88 GPR Collection Procedure………………………………………………… 90 ImageAnalysis……………………………………………………………… 93 Results……………………………………………………………………… 94 Discussion: Advantages and Limitations of GPR………………………… 95 6 BIOLOGICAL APPLICATIONS OF FULL RESOLUTION 3D GROUND PENETRATING RADAR IMAGING……………………………… 105 Introduction………………………………………………………………… 105 Methods…………………………………………………………………… 105 Results……………………………………………………………………… 106 Discussion………………………………………………………………… 106 7 OCCUPANCY OF FAUNA INHABITING GOPHER TORTOISE BURROWS LOCATED IN SCRUB AND SANDHILL VEGETATION OF CENTRAL FLORIDA……………………………………………………… 116 Introduction……………………………………………………………… 116 Study Areas……………………………………………………………… 117 Sampling Methods………………………………………………………… 118 Results…………………………………………………………………… 121 Discussion………………………………………………………………… 122 8 VERTEBRATE SPECIES RICHNESS AT AVON PARK AIR FORCE RANGE, FLORIDA ESTIMATED WITH THE JACKKNIFE…………………………………………………………………… 139 Introduction: Species Richness Estimation ……………………………… 139 7 Methods…………………………………………………………………… 143 Results……………………………………………………………………… 144 Discussion………………………………………………………………… 144 True Presence (True Positives)…………………………………… 144 False Positives …………………………………………………… 145 True Negatives …………………………………………………… 145 False Negatives and Detection Probability………………………… 147 Availability………………………………………………………… 148 Sampling Bias of Methods Used…………………………………… 151 Species Missed Due to Inappropriate or Insufficient Methods……………………………………… 152 Species Characteristics, including Rareness……………………… 154 When is a Species “Effectively Not There”?..................................... 155 Conclusion………………………………………………………………… 157 9 SUMMARY…………………………………………………………………… 166 LIST OF REFERENCES……………………………………………………………… 169 BIOGRAPHICAL SKETCH………………………………………………………… 194 8 LIST OF TABLES Table page 2-1 Diversity of animal fauna found in burrows in semi-arid environments or environments with dry, sandy soils………………………..43 3-1 Summary statistics for Gopher Tortoise burrow quadrat study conducted in four upland habitats at Avon Park Air Force Range,