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Implications of Climate Change for Food-Caching Species

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Implications of Climate Change for Food-Caching Species Demographic and Environmental Drivers of Canada Jay Population Dynamics in Algonquin Provincial Park, ON by Alex Odenbach Sutton A Thesis presented to The University of Guelph In partial fulfilment of requirements for the degree of Doctor of Philosophy in Integrative Biology Guelph, Ontario, Canada © Alex O. Sutton, April 2020 ABSTRACT Demographic and Environmental Drivers of Canada Jay Population Dynamics in Algonquin Provincial Park, ON Alex Sutton Advisor: University of Guelph, 2020 Ryan Norris Knowledge of the demographic and environmental drivers of population growth throughout the annual cycle is essential to understand ongoing population change and forecast future population trends. Resident species have developed a suite of behavioural and physiological adaptations that allow them to persist in seasonal environments. Food-caching is one widespread behavioural mechanism that involves the deferred consumption of a food item and special handling to conserve it for future use. However, once a food item is stored, it can be exposed to environmental conditions that can either degrade or preserve its quality. In this thesis, I combine a novel framework that identifies relevant environmental conditions that could cause cached food to degrade over time with detailed long-term demographic data collected for a food-caching passerine, the Canada jay (Perisoreus canadensis), in Algonquin Provincial Park, ON. In my first chapter, I develop a framework proposing that the degree of a caching species’ susceptibility to climate change depends primarily on the duration of storage and the perishability of food stored. I then summarize information from the field of food science to identify relevant climatic variables that could cause cached food to degrade. In my second chapter, I used 40 years of Canada jay reproductive performance data to understand how environmental conditions during the food storage period can carry over to influence brood size, nest success and nestling condition. I found evidence that fall freeze-thaw events, and, to a lesser degree, winter temperatures negatively influence all metrics of reproductive performance. In my third chapter, I investigated the effect of density and environmental conditions throughout the annual cycle on population growth. Fecundity was the primary vital rate driving variation in population growth and fall conditions had a strong indirect effect, acting primarily through fecundity, on population growth. In my fourth chapter, I investigated the mechanisms promoting density-dependent fecundity. I found evidence that site-dependent regulation is acting on fecundity, but only when environmental conditions are otherwise poor for breeding. Together my thesis highlights the importance of understanding how events throughout the annual cycle are connected and how such connections can, in turn, contribute to predicting population dynamics. iv ACKNOWLEDGEMENTS I would not have been able to complete my PhD and fieldwork without financial support from Ontario Graduate Scholarships, a Queen Elizabeth the II Scholarship for Science and Technology, a James L. Baillie Award from the Society of Canadian Ornithologists and Bird Studies Canada, the Ontario Ministry of Natural Resources and Forestry, the W. Garfield Weston Foundation and the Wildlife Conservation Society of Canada. I am also very thankful for the valuable assistance and support from the following people: My advisor, Ryan Norris, for his guidance throughout my PhD. He constantly pushed me to improve and has helped me become a better scientist. Dan Strickland whose pioneering work made my thesis possible. I am forever in debt to his kindness, willingness to help every step of the way and for sharing his knowledge of Canada jays and Algonquin Provincial Park. Paul Gelok, Rick Stronks, Adam Stoppa, Allison Lake and the staff of Algonquin Provincial Park for their logistic support and assistance in the field. Without their support, my winter field work would have been much harder and less enjoyable. My committee members Andrew McAdam and Hafiz Maherali for their support and guidance throughout my PhD. My lab mates, the WiP group members and office mates, past and present, especially Mason Stothart, Danielle Ethier, Grace Pitman and Sam Knight, for their friendship and willingness to chat about life and science. v My belay partners, Joey Burant and Matt Brachmann, for making my PhD about more than just science. Tim Winegard, Hugo Kitching and Patrick Moldowan who made the Algonquin Wildlife Research Station not only a place to do field work, but also a second home. My family for supporting my interest in science and wildlife, regardless of how odd it may have seemed. Finally, I would like to thank my partner in crime Koley Freeman who has made this adventure so much more than just a degree. Through the frigid cold, across sketchy ladders and around the world, every moment has been better because you have been there with me. vi TABLE OF CONTENTS ABSTRACT ................................................................................................................................................ II ACKNOWLEDGEMENTS ..................................................................................................................... IV TABLE OF CONTENTS ......................................................................................................................... VI LIST OF TABLES .................................................................................................................................. XII LIST OF FIGURES ................................................................................................................................ XV 1 GENERAL INTRODUCTION............................................................................................................ 1 2 CHAPTER 1 - FOOD STORAGE IN A CHANGING WORLD: IMPLICATIONS OF CLIMATE CHANGE FOR FOOD-CACHING SPECIES ..................................................................... 8 2.1 ABSTRACT ........................................................................................................................................... 8 2.2 INTRODUCTION ................................................................................................................................... 9 2.3 RELATING THE POTENTIAL EFFECTS OF CLIMATE CHANGE TO THE COSTS AND BENEFITS OF CACHING ..................................................................................................................................................... 11 2.4 PREDICTING THE SUSCEPTIBILITY OF FOOD-CACHING SPECIES TO CLIMATE CHANGE .............. 13 2.5 INTEGRATING CONCEPTS FROM FOOD SCIENCE TO UNDERSTAND THE SUSCEPTIBILITY OF PERISHABLE FOOD TO CLIMATE CHANGE ................................................................................................ 20 vii 2.6 INTEGRATING CONCEPTS FROM PLANT BIOLOGY TO UNDERSTAND THE SUSCEPTIBILITY OF NON-PERISHABLE FOOD TO CLIMATE CHANGE ........................................................................................ 27 2.7 LINKING FOOD-DEGRADING ENVIRONMENTAL CONDITIONS WITH CLIMATE CHANGE .............. 30 2.8 EXTRACTING CLIMATIC VARIABLES FROM HISTORICAL WEATHER DATA .................................. 31 2.9 CHARACTERISTICS OF CACHING SPECIES THAT COULD MITIGATE THE IMPACT OF CLIMATE CHANGE ...................................................................................................................................................... 33 2.10 CONCLUSIONS AND FUTURE DIRECTIONS ..................................................................................... 36 2.11 TABLES ............................................................................................................................................ 38 2.11.1 SUMMARY OF VERTEBRATE CACHING SPECIES ................................................................................. 38 2.12 FIGURES .......................................................................................................................................... 52 2.12.1 PREDICTED SUSCEPTIBILITY OF FOOD-CACHING SPECIES TO CLIMATE CHANGE .............................. 52 3 CHAPTER 2 - FALL FREEZE-THAW EVENTS CARRY OVER TO DEPRESS LATE- WINTER REPRODUCTIVE PERFORMANCE IN CANADA JAYS ............................................... 54 3.1 ABSTRACT ......................................................................................................................................... 54 3.2 INTRODUCTION ................................................................................................................................. 55 3.3 METHODS .......................................................................................................................................... 58 3.3.1 STUDY AREA AND SPECIES ................................................................................................................ 58 3.3.2 REPRODUCTIVE PERFORMANCE ....................................................................................................... 59 3.3.3 HISTORICAL WEATHER DATA ............................................................................................................. 60 3.3.4 QUANTIFYING WEATHER VARIABLES ................................................................................................. 61 3.3.5 STATISTICAL ANALYSIS ...................................................................................................................... 61 3.4 RESULTS ...........................................................................................................................................
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