THINKING OUTSIDE THE BOX: EFFECTS OF ENVIRONMENTAL ENRICHMENT AND REARING DURATION ON HEAD-STARTING SUCCESS OF BOX TURTLES BY SASHA JAMES TETZLAFF DISSERTATION Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Natural Resources and Environmental Sciences in the Graduate College of the University of Illinois at Urbana-Champaign, 2019 Urbana, Illinois Doctoral Committee: Associate Professor Robert L. Schooley, Chair Adjunct Assistant Professor Jinelle H. Sperry, Director of Research Dr. Brett A. DeGregorio, University of Arkansas Associate Professor Michael P. Ward Professor Bruce A. Kingsbury, Purdue University Fort Wayne ii ABSTRACT Translocation is the deliberate movement and release of animals and a common management technique in wildlife conservation programs. However, efforts are often unsuccessful because relocated animals have low survival, precluding population establishment. I reviewed studies using antipredator training, environmental enrichment, and soft release as pre- release behavioral conditioning in translocation programs, and I quantitatively synthesized how these approaches affect post-release success. I then conducted experiments using captive-reared juvenile eastern box turtles (Terrapene carolina) raised with or without naturalistic environmental enrichment to better understand mechanisms influencing habitat preferences in captivity. Next, I investigated if enrichment encouraged natural behaviors before turtles were released into the wild and how being raised in enriched environments affected growth over differing rearing periods (nine vs. 21 months). Finally, I examined how enrichment and captive- rearing duration affected the turtles’ post-release growth, behavior, and survival. Meta-analysis conducted on 108 effect sizes from 41 studies investigating the effects of pre-release behavioral conditioning on translocation outcomes revealed conditioned animals had higher survival, reduced movement, and greater site fidelity than unconditioned individuals. Notably, antipredator training, environmental enrichment, and soft release all resulted in improved survival. This suggests pre-conditioning is likely an important tool for improving future wildlife translocations. When I provided environmental enrichment to captive-born eastern box turtles, they preferred enriched environments, regardless of prior housing experience, suggesting this preference is innate. Thus, enrichment likely enhances welfare of captive box turtles by satisfying an instinctive desire to occupy complex habitat. However, pre-release trials revealed iii enriched turtles performed no better in ecologically relevant foraging tasks than unenriched turtles. In a predator recognition test, eight-month-old enriched turtles avoided raccoon (Procyon lotor) urine more than unenriched turtles of the same age, but this difference was not apparent one year later. These findings suggest any behavioral benefits conferred by enrichment were modest. Enriched turtles also attained smaller body sizes overall than unenriched turtles pre- release. Enrichment had minimal effects on post-release behavior and survival. However, turtles raised for 21 months moved farther from the release site and had higher post-release survival than those raised for only nine months, regardless of rearing environment. Although raising animals in enriched captivity can increase translocation success for several taxa, my experiments with box turtles and similar previous studies indicate enrichment might have limited utility for enhancing reptile translocations. Instead, implementing a longer rearing period to maximize body size before release appears to most benefit survival by reducing susceptibility to predation, which is commonly cited as a hindrance to post-release success. iv For Kristin v ACKNOWLEDGEMENTS Being a graduate student isn’t so much of an island as it is a peninsula; you’re largely out there on your own, but right behind you is support in the form of advisors, lab mates, committee members, professors, family, friends, and many others. I’ve been lucky enough to have support from all such people during my Ph.D. program, and I will be forever grateful for that. There are many individuals and organizations to thank for their contributions that made this dissertation possible. First, I thank my advisors, Drs. Brett DeGregorio and Jinelle Sperry. It has been an honor to be Brett’s first graduate student, part of Jinelle’s growing list of Ph.D. students, and a “grandchild” of the Weatherhead Lab. The support from Brett and Jinelle was more than I could have asked for, and their commitment to graduate student training has been inspirational. I am extremely appreciative for the chance they took on me and providing me such amazing opportunities. Brett: thank you for working so closely with me during this time. Your ingenuity, never-ending drive, and patience helped make the most of our work. Jinelle: thanks for being so uplifting and optimistic. The diversity of successful students that have and continue to come through the Sperry Lab clearly demonstrates how great of an environment it is to be in. I also thank the rest of my dissertation committee members, Drs. Mike Ward, Bob Schooley, and Bruce Kingsbury. Each brought unique perspective to this work that helped improve it. For their companionship and productive discussions, I thank current and former lab mates Ellery Ruther, Jason Gleditsch, Stephen Tyndel, Sean MacDonald, Dr. Valerie Buxton, Dr. Jef Vizentin-Bugoni, Dylan O’Hearn, Brittney Graham, Dr. Aron Katz, Libby Sternhagen, Pat Wolff, and Daniel Kovar. Karen Claus, Courtney Lynch, Lezli Cline, and Kelly Sullan in the Department of NRES were so patient and helpful with my incessant need for administrative- vi related assistance. This work was supported by funds from the United States Department of Defense’s Environmental Security Technology Certification Program. For assistance in the field and laboratory, I thank Jessie Birckelbaw, Sara Desmond, Odell Encinosa, Alondra Estrada, Richael Mavesi, David Messmann, Charlotte Robinson, Nicholas Schiltz, Maddie Terlap, David, Kyle, and Jack Tetzlaff, Karen Watson, Pat Wolff, and Wayne, Melinda, and Adrian Yerdon. Everyone who assisted with field and laboratory work deserves my endless gratitude, but Nick’s prodigious ability to locate box turtle nests is the primary reason Chapters 3–5 came to fruition. Charlotte’s hard work in the field made several side projects possible and allowed me to be a less absent husband and father. Dave Messmann also deserves extra recognition; his help and companionship in the field will never be forgotten. Brian Huggett, Jim Langerveld, and Jonathan Edgerly were instrumental in facilitating fieldwork at Fort Custer Training Center. Dr. T.J. Benson graciously loaned equipment that facilitated hours of turtle watching during laboratory behavioral trials. I thank my entire family for their continued support. The Szydlowski family (Mike, Nicole, Ashleigh, Bradley, and Peyton) and Mitzi Szwajkowski deserve a special shout out for letting Kris and the kids spend so much time with them when I was away in the field. Having the support of family relatively close by while completing a Ph.D. made it more survivable by far. Lastly and most importantly, thank my wife, Kristin, and our sons, Jack and Luke. Boys: You have been a source of inspiration throughout this process and a constant reminder of what is truly important. Thanks for being good sports about me having to be away in the field, at a conference, or in the lab writing on weekends, but I’m happy we were able to make some of my dissertation work into family time. Bringing you over to the greenhouse to check on the turtles vii will be among some of my favorite memories of our young family. Kris: We did it. This dissertation is dedicated to you, as it’s just as much yours as it is mine. Before we met I had considered dropping out of college, but your endless love, support, and selflessness every step of the way is without a doubt the main reason why we got to this point. I can only hope I’ll be able to repay you for the sacrifices you’ve made for our family. I love you and our boys more than I’ll ever be able to express. viii TABLE OF CONTENTS CHAPTER 1: GENERAL INTRODUCTION ..................................................................... 1 CHAPTER 2: EFFECTS OF ANTIPREDATOR TRAINING, ENVIRONMENTAL ENRICHMENT, AND SOFT RELEASE ON WILDLIFE TRANSLOCATIONS: A REVIEW AND META-ANALYSIS .......................................... 8 CHAPTER 3: CAPTIVE-REARED JUVENILE BOX TURTLES INNATELY PREFER NATURALISTIC HABITAT: IMPLICATIONS FOR TRANSLOCATION ............................................................................................................. 43 CHAPTER 4: TRADEOFFS WITH GROWTH AND BEHAVIOR FOR CAPTIVE BOX TURTLES HEAD-STARTED WITH ENVIRONMENTAL ENRICHMENT .................................................................................................................... 68 CHAPTER 5: CAPTIVE-REARING DURATION MAY BE MORE IMPORTANT THAN ENVIRONMENTAL ENRICHMENT FOR ENHANCING TURTLE HEAD-STARTING SUCCESS ................................................... 93 CHAPTER 6: SUMMARY ................................................................................................... 126 APPENDIX: SUPPLEMENTARY DATA FROM CHAPTER 2 ........................................ 130 1 CHAPTER 1: GENERAL INTRODUCTION Wildlife conservation translocations entail deliberate movement and release of animals, often