ECOLOGY AND ECOPHYSIOLOGY OF BURYING BEETLES IN A FRAGMENTED EASTERN DECIDUOUS FOREST by Brandon Quinby A Dissertation Submitted to the Faculty of Purdue University In Partial Fulfillment of the Requirements for the degree of Doctor of Philosophy Department of Forestry and Natural Resources West Lafayette, Indiana August 2020 THE PURDUE UNIVERSITY GRADUATE SCHOOL STATEMENT OF COMMITTEE APPROVAL Dr. Elizabeth A. Flaherty, Co-Chair Department of Forestry and Natural Resources Dr. J. Curtis Creighton, Co-Chair Purdue Northwest, Department of Biology Dr. Michael A. Jenkins Department of Forestry and Natural Resources Dr. Matthew D. Ginzel Department of Forestry and Natural Resources Approved by: Dr. Robert Wagner 2 To my friends and family for their love and support. 3 ACKNOWLEDGMENTS During the last four years, I have thoroughly enjoyed my time spent at Purdue. I am grateful to many people for making it such a fulfilling experience. First and foremost, I thank Drs. Liz Flaherty and Curtis Creighton for being outstanding research and educational mentors. I could not have asked for better advisors. They were committed in their support of me, even when things didn’t go as planned, and graciously allowed me to pursue my research and teaching interests. For that, I am sincerely grateful. My other committee members, Dr. Michael Jenkins and Dr. Matt Ginzell, were instrumental to the successful completion of this project, and my dissertation benefited greatly from their thoughtful insight and direction. I am blessed to have been a part of the Forestry and Natural Resources Department at Purdue as well as the greater Lafayette community where I have met so many wonderful people. Specifically, I thank Chelsea, Jacob, Ashley, Cami, Jessie, Jameson, Anna, Samarth, Chris, Jennifer, Daniel, Patrick, Suse, Patricia, Logan, and Claire for their help with my project, keeping me on track, keeping me sane, putting up with me through all of this, and their general support when it was most needed. I am also extremely thankful for the numerous undergraduate students that I worked with or had the pleasure of teaching over the course of my tenure at Purdue. I truly enjoyed, and was bettered by, my experiences serving as an undergraduate mentor and instructor. A big thank you to all of my collaborators, most notably, Lou, Emily, Scott, and Danielle. Without your support and guidance, the field work component of my dissertation would not have been possible. Lastly, I would like to thank my family and friends for their ongoing and overwhelming support! I thank my father and stepmother for always being in my corner and providing me with the support and love needed during graduate school. I thank my mother for her love and being the biggest cheerleader, even though I am pretty sure she still does not understand exactly what I do. I would also like to say a special thank you to Vanessa Quinn. Without your guidance and mentorship, I would not be here today, and I am extremely lucky to count you as a friend and mentor. Additionally, I would like to thank my friends outside of academia in the greater Lafayette community, you made The Spot feel like a home away from home. Lastly I would like to thank Zack, Edgar, and Rabbit for keeping me sane! 4 TABLE OF CONTENTS LIST OF TABLES .......................................................................................................................... 9 LIST OF FIGURES ...................................................................................................................... 10 LIST OF ABBREVIATIONS ....................................................................................................... 11 ABSTRACT .................................................................................................................................. 12 BURYING BEETLE ECOLOGY AND CONSERVATION ............................. 14 1.1 Introduction ....................................................................................................................... 14 1.2 Journal Selections and Justification .................................................................................. 17 1.3 References ......................................................................................................................... 18 STABLE ISOTOPE ECOLOGY IN INSECTS: A REVIEW ............................ 20 2.1 Abstract ............................................................................................................................. 20 2.2 Introduction ....................................................................................................................... 21 2.2.1 Stable Isotopes in Entomology .................................................................................. 21 2.2.2 Stable Isotope Ecology Basics ................................................................................... 21 2.2.3 Sources of Variation in Stable Isotopes ..................................................................... 23 2.2.4 Stable Isotope Incorporation ...................................................................................... 24 2.2.5 Stable Isotope Routing ............................................................................................... 24 2.2.6 Diet-Tissue Discrimination ........................................................................................ 25 2.3 Quantifying Nutrient Flows, Trophic Relations, and Insect Diets Using Natural Abundance Stable Isotopes ........................................................................................................................... 26 2.3.1 Stable Isotope Mixing Models ................................................................................... 26 2.3.2 Lipid Extraction Versus Concentration-Dependent Mixing Models ......................... 28 2.3.3 Compound-Specific Isotope Analysis ....................................................................... 28 2.4 Stable Isotope Applications in Entomological Research .................................................. 29 2.4.1 Carbon and Nitrogen Stable Isotopes in Entomology ............................................... 29 2.4.2 Hydrogen and Oxygen Stable Isotopes in Entomology ............................................. 30 2.4.3 Diet Assimilation and Turnover ................................................................................ 30 2.4.4 Feeding Behaiour ....................................................................................................... 31 2.4.5 Dispersal .................................................................................................................... 31 2.4.6 Mating and Sperm Competition................................................................................. 32 5 2.5 Mistakes, Considerations, and Future Directions ............................................................. 33 2.5.1 Use Previous Knowledge and Caution ...................................................................... 33 2.5.2 Quality Control .......................................................................................................... 34 2.5.3 Insect Specific Considerations ................................................................................... 35 2.5.4 Future Directions for Entomological Studies ............................................................ 35 2.6 Conclusions ....................................................................................................................... 36 2.7 Acknowledgments............................................................................................................. 36 2.8 References ......................................................................................................................... 37 EVALUATION OF THE VERTEBRATE CARRION RESOURCES USED BY THE AMERICAN BURYING BEETLE (NICROPHORUS AMERICANUS) ............................ 62 3.1 Highlights .......................................................................................................................... 62 3.2 Abstract ............................................................................................................................. 62 3.3 Introduction ....................................................................................................................... 63 3.4 Materials and Methods ...................................................................................................... 67 3.4.1 Study Area ................................................................................................................. 67 3.4.2 Sample Collection ...................................................................................................... 67 Burying Beetle Sampling .................................................................................................... 67 Small Mammal and Bird Sampling ..................................................................................... 69 3.4.3 Stable Isotope Sample Analysis................................................................................. 70 3.4.4 Statistical Analysis ..................................................................................................... 71 3.5 Results ............................................................................................................................... 72 3.5.1 Reproductive Carrion ................................................................................................. 72 3.5.2 Stable Isotope Analysis .............................................................................................