SONAR JAMMING IN THE BAT-MOTH ARMS RACE BY AARON J. CORCORAN A Dissertation Submitted to the Graduate Faculty of WAKE FOREST UNIVERSITY GRADUATE SCHOOL OF ARTS AND SCIENCES in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY Biology May, 2013 Winston-Salem, North Carolina Approved By: William E. Conner, Ph.D., Advisor Nickolay Hristov, Ph.D., Chair Miriam Ashley-Ross, Ph.D. Robert Browne, Ph.D. Susan Fahrbach, Ph.D. ii DEDICATION To the late James Fullard, the primary proponent of the jamming hypothesis. You meant so much to me, despite our brief acquaintance. iii ACKNOWLEDGEMENTS To say thank you is not nearly enough for the numerous people who have inspired me, taught me, challenged my thinking repeatedly in the kindest of ways, and worked by my side night after night until the sun rose. But here I attempt to do just that. First, I thank Dr. William (“Bill”) Conner, my academic advisor and mentor over the last five years. You taught me what it means to be a scientist in the most complete sense of the word. Somehow you always knew when to give me a push and when to let me find my own way (usually the latter). I know few people with your breadth of knowledge from genes to neurons to behaviors to ecosystems and more. And you have an uncanny ability to relate that knowledge to your students whether in the classroom or one-on-one. You taught me how to simplify a problem into its constituent parts and dissect it experimentally with the skill of a surgeon. Your door was always wide open, literally and figuratively and you treated me as a friend and colleague from day one. I thank my academic committee – Drs. Miram Ashley-Ross, Robert Browne, Susan Fahrbach, and Nickolay Hristov – for pushing my boundaries as a scientist. I must also thank my master’s advisor, Dr. Joe Szewczak, for sharing his love of bats with me; my brothers Dan and Tim Corcoran and Tom Brown Jr. for inspiring in me a love of all things wild; and my mom and dad for teaching me to always follow my heart and for unending faith that I would find my path in life. I thank my wife, Lauren, for keeping me grounded and humble through this journey. Many others contributed directly to my research. Dr. Jesse Barber and Dr. Nickolay Hristov, my academic elder brothers, set the stage for this work with their ground-breaking studies on bats and moths. They also selflessly helped me at every turn, be that training me how to care for and raise baby bats, how to use high-speed cameras or develop 3-D models, or whatever the moment demanded. I had five extraordinary Wake Forest undergraduate researchers – Megan Cullen, Wesley Johnson, Ryan Wagner, Zachary Walker, and Kaitlyn Roman – work with me over the summers at Wake and in southern Arizona. I could not have asked for a harder working or more insightful and intelligent group to work with than you. I am especially thankful to Ryan Wagner, whose exceptional devotion to the project led to chapter five of this dissertation. My good friends Jean-Paul Kennedy and Nick Dowdy also worked with me in the field in Arizona and your companionship and dedication made all the difference, especially on those nights when everything seemed to go wrong and all there was left to do was crack open a beer and watch the sun rise. I am also especially grateful to the staff, interns and fellow researchers at the Southwestern Research Station where I spent four summers studying bats and moths. There are too many of you to name here, but your help and comradery brought me joy as iv much as did the charismatic bats and moths I got to know so well. Several people also helped with the many technological challenges of this work. Most notably, Jeff Muday was always at hand to fix a computer glitch, or even build a new computer. Mark Jenson built a custom microphone to specification for chapter five; Manfred Berger provided assistance with his Maxtraq software and Brad Chadwell graciously provided computer code and gave me lessons on 3D Geometry. Finally, I must thank Mindy Conner, who graciously edited many of the pages of this work. Of course any errors left here are mine alone. Chapter-specific acknowledgements Chapter II -- I thank F. Insana and the staff of the Southwestern Research Station for assistance collecting B. trigona ; M. Cullen for providing bat care and training; N. Hristov and J. Muday for technical assistance; and B. Chadwell for software. M. Conner, J.-N. Jasmin, T. Eisner, and the Wake Forest University ecology group provided editorial comments. Funding for research was provided by National Science Foundation Grant IOB-0615164 to W.E.C. and a W.F.U. Dean’s Fellowship to A.J.C. CHAPTER III – I am most grateful to Frank Insana, Jeff Paull, and the staff of the Southwestern Research Station for assistance collecting B. trigona ; Megan Cullen for bat care; Jeff Muday for technical support; and Brad Chadwell for software development. Two anonymous reviewers provided several insightful and constructive comments. Funding was provided by grant #IOB-0615164 to W. E. C. by the National Science Foundation. CHAPTER IV -- I thank Wesley Johnson, Ryan Wagner, Zachary Walker, Jean-Paul Kennedy, Nick Dowdy and several Southwestern Research Station interns for assistance in the field. Brad Chadwell provided software for 3-D calculations. Nickolay Hristov helped develop our field recording setup. Jeff Muday provided technical assistance, and the staff of the Southwestern Research Station provided valuable logistical support. Melinda Conner edited the manuscript, and two anonymous reviewers provided numerous valuable comments. CHAPTER V -- I thank the staff and interns of the Southwestern Research Station of the American Museum of Natural History for logistical support. Dr. Bradley Chadwell provided software for 3-D analysis. Jeffrey Muday provided technical computing support. Funding was provided by National Science Foundation grant number IOS-0615164 and IOS-0951160 to W. E. C. v TABLE OF CONTENTS Page DEDICATION .................................................................................................................... ii ACKNOWLEDGEMENTS ............................................................................................... iii LIST OF FIGURES ......................................................................................................... viii LIST OF TABLES ............................................................................................................. xi ABSTRACT ...................................................................................................................... xii CHAPTER I Bats and tiger moths: an introduction ......................................................................1 CHAPTER II Tiger moth jams bat sonar Published in Science (2009) ABSTRACT ...............................................................................................17 INTRODUCTION .....................................................................................18 METHODS ................................................................................................20 RESULTS/DISCUSSION..........................................................................21 REFERENCES AND NOTES ...................................................................24 SUPPORTING MATERIAL .....................................................................29 CHAPTER III How do tiger moths jam bat sonar? Published in Journal of Experimental Biology (2011) ABSTRACT ...............................................................................................42 INTRODUCTION .....................................................................................43 vi MATERIALS AND METHODS ...............................................................46 RESULTS ..................................................................................................53 DISCUSSION ............................................................................................58 CONCLUSION ..........................................................................................64 REFERENCES ..........................................................................................66 CHAPTER IV Sonar jamming in the field: Effectiveness and behavior of a unique prey defense Published in Journal of Experimental Biology (2012) ABSTRACT ...............................................................................................83 INTRODUCTION .....................................................................................84 MATERIALS AND METHODS ...............................................................87 RESULTS ..................................................................................................93 DISCUSSION ............................................................................................96 CONCLUSION ........................................................................................105 REFERENCES ........................................................................................108 CHAPTER V Optimal predator risk assessment by the sonar-jamming moth Bertholdia trigona ABSTRACT .............................................................................................125 INTRODUCTION ...................................................................................126 MATERIALS AND METHODS .............................................................131 RESULTS ................................................................................................139 DISCUSSION