! ! ! ! ! ! ! Sexual!dimorphism!and!alternative!reproductive!tactics!in!the!Midland!Painted! Turtle!(Chrysemys(picta(marginata)! ! ! ! by! ! ! ! Patrick!D.!Moldowan! ! ! ! A!thesis!submitted!in!partial!fulfillment! Of!the!requirement!for!the!degree!of! Master!of!Science!(MSc)!in!Biology! ! ! ! The!Faculty!of!Graduate!Studies! Laurentian!University! Sudbury,!Ontario,!Canada! ! ! ! ©!Patrick!D.!Moldowan,!2014! ! ! ! ! ! ! ! ! ! ! ! THESIS DEFENCE COMMITTEE/COMITÉ DE SOUTENANCE DE THÈSE Laurentian Université/Université Laurentienne Faculty of Graduate Studies/Faculté des études supérieures Title of Thesis Titre de la thèse SEXUAL DIMORPHISM AND ALTERNATIVE REPRODUCTIVE TACTICS IN THE MIDLAND PAINTED TURTLE (Chrysemys picta marginata) Name of Candidate Nom du candidat Moldowan, Patrick David Degree Diplôme Master of Science Department/Program Date of Defence Département/Programme Biology Date de la soutenance August 29, 2014 APPROVED/APPROUVÉ Thesis Examiners/Examinateurs de thèse: Dr. Jacqueline Litzgus (Supervisor/Directeur(trice) de thèse) Dr. Albrecht Schulte-Hostedde (Committee member/Membre du comité) Dr. Ronald J. Brooks (Committee member/Membre du comité) Approved for the Faculty of Graduate Studies Approuvé pour la Faculté des études supérieures Dr. David Lesbarrères M. David Lesbarrères Dr. Brent Thomas Acting Dean, Faculty of Graduate Studies (External Examiner/Examinateur externe) Doyen, Faculté des études supérieures ACCESSIBILITY CLAUSE AND PERMISSION TO USE I, Patrick David Moldowan, hereby grant to Laurentian University and/or its agents the non-exclusive license to archive and make accessible my thesis, dissertation, or project report in whole or in part in all forms of media, now or for the duration of my copyright ownership. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also reserve the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. I further agree that permission for copying of this thesis in any manner, in whole or in part, for scholarly purposes may be granted by the professor or professors who supervised my thesis work or, in their absence, by the Head of the Department in which my thesis work was done. It is understood that any copying or publication or use of this thesis or parts thereof for financial gain shall not be allowed without my written permission. It is also understood that this copy is being made available in this form by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. Abstract The reproductive strategy of Painted Turtles (Chrysemys picta) has been described as a combination of male courtship and female mate choice. However, in situ field observations from a long-term study of C. picta in Algonquin Provincial Park (Ontario, Canada) suggest that males also demonstrate coercive mating tactics. Males are equipped with prominent tomiodonts, tooth-like cusps of the upper jaw, which seemingly function in restraining mates and result in wounding to the head and neck of females. I propose that the tomiodonts of male C. picta serve as sexual weapons used to coerce females into mating. This thesis has two main objectives: 1) to describe the tomiodont morphology of C. picta, and 2) to test the functional significance of tomiodonts in the mating tactics of male C. picta. In Chapter I, I investigate the overall cranial morphology of C. picta with an emphasis on sexual dimorphism of the tomiodonts. I show that male C. picta have sexually size dimorphic tomiodonts with an optimized arrangement for biting and gripping. In Chapter II, I investigate the soft tissue wounding demographics of a C. picta population as these wounds relate to antagonistic sexual interactions. Using a 24-year dataset on wounding I show that large females experience the highest wounding probability and that elevated rates of wounding occur during the late summer breeding period. In Chapter III, I use behavioural trials during the spring and late summer reproductive seasons to evaluate male reproductive behaviour. I show that small males court females through titillation, whereas larger males employ coercive tactics, such as biting and forced submergence. My findings are contrary to the female choice mating system reported for C. picta and join a growing body of research demonstrating the importance of coercive tactics in the reproduction of male emydid turtles. functional morphology, comparative morphology, sexual dimorphism, animal behaviour, animal reproduction, sexual conflict, sexual behaviour, herpetology, freshwater turtle, natural history. ! iii! Acknowledgements This project was only made possible through the invaluable assistance and support of mentors, family, and friends. I extend sincere thanks to all that have contributed to this thesis and who have shared their curiousity for the “secret love life of the Painted Turtle”. Many thanks to … Dr. Jacqueline Litzgus: For your open-minded advising, encouragement, patience, and excitement. Thank you for taking a chance on the mysterious Painted Turtle tomiodonts! Dr. Ron Brooks: For your mentoring, fierce dedication, and passion for all facets of evolution, chelonian biology, conservation, and much, much more. Thank you for your foresight and willingness to share Algonquin turtle lore. Dr. Albrecht Schulte-Hostedde: For your critical and insightful commentary. Dr. Brent Thomas: For serving as my external thesis examiner and sharing his enthusiasm for turtle biology. Algonquin Wildlife Research Station: For training generations of exceptional young biologists, being a home away from home, and serving as an inspiration to all those who have visited for over 70 years. Glenn Tattersall: For your introduction to field biology and the opportunity to get my feet wet and hands dirty with salamander research at the AWRS. David LeGros: For taking a naïve biologist-in-training under your wing and always offering up a listening ear, a keen naturalist’s eye, thought provoking observations, insightful discussion, and a cold drink. LF3 forever, my friend! Matt Keevil: For your guidance, mentorship, and sharing of seemingly endless knowledge. Know that your research ideas and statistical proficiency are greatly appreciated. May there be many more turtle nesting seasons, bouts of waist deep bog wading for Snapping Turtles, and laughs as we continue our no turtle left behind program! Julia Riley: For your scientific curiousity, initiative to begin measuring turtle heads, and boundless excitement for the natural world. James Baxter-Gilbert, Sean Boyle, and other members of the Litzgus Lab: For your comraderie and continual inspiration at all points during this project. Rory Eckenswiller, Paul Gelok and Jenn Hoare: For your unwavering logistical support, keen interest, dedicated friendship, and countless opportunities in Algonquin Park. May the Moldowan School of Tomiodontistry soon follow! ! iv! Thank you to field assistants and friends Shawna Sanders, Jason Flatt, Michelle Anagnostou, Brittainy Hewitt, Steven Kell, among others, for their many contributions in the field. Thank you to the countless past Turtlers for their dedication to the Algonquin Turtle Project. Kirsten Henderson: For your unconditional support in the field and throughout the writing process and tolerating more turtle talk than anyone should ever have to endure My Mom, Dad, and Sis: For your love, constant encouragement, doses of concern, and fostering of my interest in the creepy, crawly, slithery, and slimy from an early age. The Algonquin Turtles: For being model research subjects and fascinating to boot! Funding and in-kind support for this project provided by Laurentian University, University of Guelph, Natural Sciences and Engineering Research Council of Canada, Ontario Parks, Friends of Algonquin Park, Sudbury Game and Fish Protective Association, Ruffed Grouse Society, John Carl MacIssac Foundation, Canadian Association of Herpetologists, and the Society for the Study of Amphibians and Reptiles. “There’s no simple Explanation For anything important Any of us do” Gord Downie, The Tragically Hip “Courage (for Hugh MacLennan)”, Fully Completely (1992) ! v! Table of Contents General Introduction ……………………………………………………………………1 Chapter I: Head morphology, tomiodont characterization and sexual dimorphism in the Midland Painted Turtle (Chrysemys picta marginata) Introduction …………………………………………………………………………….29 Methods …………………………………………………………………………………31 Results …………………………………………………………………………………..37 Discussion ………………………………………………………………………………40 Chapter II: Sexual coercion and demographics of injuries from conspecific bites in a population of Midland Painted Turtles (Chrysemys picta marginata) in Algonquin Provincial Park Introduction …………………………………………………………………………….78 Methods …………………………………………………………………………………84 Results …………………………………………………………………………………..88 Discussion ………………………………………………………………………………92 Chapter III: Courtship or coercion? Alternative reproductive tactics in the Midland Painted Turtle (Chrysemys picta marginata) Introduction …………………………………………………………………………...131 Methods ………………………………………………………………………………..138 Results …………………………………………………………………………………142 Discussion ……………………………………………………………………………..148 General Conclusion …………………………………………………………………...191 Appendix I …………………………………………………………………………….193 Appendix II ……………………………………………………………………………212 Appendix