Habitat quality, torpor expression and pathogen transmission in little brown bats (Myotis lucifugus) By Ana M. Breit A thesis submitted to the Faculty of Graduate Studies in partial fulfilment of the requirements for the Master of Science Degree Department of Biology Master of Science in Bioscience, Technology, and Public Policy University of Winnipeg Winnipeg, Manitoba, Canada March 26, 2018 1 Table of Contents List of Tables ......................................................................................................................3 List of Figures .....................................................................................................................4 CHAPTER 1: GENERAL INTRODUCTION ................................................................5 Objectives and Hypotheses ..............................................................................16 Ethical statement ..............................................................................................18 References .........................................................................................................19 CHAPTER 2: EFFECTS OF ROOST TEMPERATURE ON TORPOR EXPRESSION AND PATHOGEN ACQUISITION IN SOLITARY LITTLE BROWN BATS.................................................................................................................29 Abstract .............................................................................................................29 Introduction ......................................................................................................30 Methods .............................................................................................................35 Results ...............................................................................................................43 Discussion ..........................................................................................................52 References .........................................................................................................57 CHAPTER 3: EFFECTS OF ROOST TEMPERATURE ON AGGREGATION AND TORPOR EXPRESSION BY GROUPS OF LITTLE BROWN BATS ...........64 Abstract .............................................................................................................64 Introduction ......................................................................................................65 Methods .............................................................................................................71 Results ...............................................................................................................80 Discussion ..........................................................................................................96 References .......................................................................................................103 CHAPTER 4: GENERAL CONCLUSIONS...............................................................111 2 Acknowledgements I cannot overstate my gratitude to the numerous humans who helped me with this thesis. Thank you to my incredible supervisor, Craig Willis, who not only trained me as a researcher and writer, but also mentored me and literally gave me a bed to sleep on, as well as a few beers over the years. Thank you to Quinn “Heather Mayberry” Fletcher, for teaching me how to speak the language of R. You kept me sane and there would have been so many more tears and broken windows/computers if it hadn’t been for your patience and expertise. I owe you a lifetime of beers. A million and one thanks to Kaleigh Norquay. You were my first friend in Canada, and then my first family here too. Thank you so much for not only being my bat-sister and mentoring me in science, but even more for making me part of your family. You have an amazing support system that you shared with me and I cannot express my gratitude enough. Moving to Winnipeg was one of the hardest things I’ve done in my life, and thanks to you, moving away will be even harder. Thank you also to my amazing labmates and field technicians who literally kept me and my project alive. Specific thanks to Emma Kunkel, who stuck by me through not only the fieldwork mishaps but also through the analysis and writing portion of this thesis. Your companionship over the last couple years has meant more to me than words can describe (see Appendix 2: Love letter to Emma L. Kunkel). Thank you also to Yvonne Dzal, Nicole Dorville, Andrew Habrich, and Trevor Moore, for listening to so many renditions of this thesis and presentations, and then still being my friend afterwards. Working with you all has been amazing and I will miss you so much. Thank you also to my support system of fellow graduate students at the University of Winnipeg. It has been a fantastic ride with all of you. Finally, thank you to my family. Thank you, Yusuf, for not only the food, shelter, and protection, but also for the support, encouragement, and companionship. Your patience and humor kept this thesis a part of my life instead of the definition of my life. Thank you. I love you. And most importantly, thank you to my mom and dad. Thank you Papa, for taking me to into the woods before I could walk. Those memories of us listening to Sandhill cranes at our spot in the wedge are some of the happiest and most peaceful moments of my life. I love you. And thank you to my mom, for being so encouraging at times it was scary. Your love and enthusiasm is out of this world. Thank you especially for watching bats with me in the backyard, where it all began. I love you both so much. Thank you. 3 List of Tables Table 2.1: Summary of morphometric data and raw data for each animal used in analysis of torpor expression and infection intensity. *Original value of zero was assumed to be below the limit of detection so was changed to the lowest detection divided by 2 (see methods)…………………………………………………………….....44 Table 2.2: Summary of linear mixed effects model assessing effects of average Troost (with trial as a random effect, p<0.0001) on normothermy index of 15 little brown bats (n=6 male, 9 female) over 9 24-hour trials………...………………………..45 Table 2.3: Summary of linear mixed effects model assessing effects of normothermy index (with trial as a random effect, p=0.0001) on pathogen acquisition of 15 little brown bats (n=6 male, 9 female) over 9 24-hour trials………………………….48 Table 3.1: Summary of linear mixed effects model assessing effects of group size, average Troost, their interaction term, sex, and mass (with trial as a random effect, p<0.0001) on normothermy index of 68 little brown bats (n= 22 male, 45 female) over 11 24-hour trials…………………………………………………………....85 Table 3.2: Summary of linear mixed effects model assessing effects of average Troost, sex, and mass (with trial as a random effect, p<0.0001) on normothermy index of 18 little brown bats (n= 8 males, 10 females) that roosted in small-sized groups (1-3 individuals)…………………………………………………………………..…..88 Table 3.3: Summary of linear mixed effects model assessing effects of average Troost, sex, and mass (with trial as a random effect, p<0.0001) on normothermy index of 35 little brown bats (n= 7 males, 28 females) that roosted in large-sized groups (7-10 individuals)………………………………………………………………………89 Table 3.4: Summary of linear mixed effects model assessing effects of average Troost, sex, and mass (with trial number as a random effect, p<0.0001) on nomothermy index of 14 little brown bats (n= 7 male, 7 female) that roosted in medium-sized groups (4-6 individuals)…………………….……………………………………………90 Table 3.5: Summary of linear mixed effects model assessing effects of group size, normothermy index, their interaction term, and sex (with trial as a random effect) on the logit-transformed intensity of infection of 68 little brown bats over 11 24- hour trails………………………………………………………………….……..92 4 List of Figures Figure 2.1: Boxplot of daily average Troost in both heated and control roost boxes in heated and control flight enclosures. Centre lines represent median values, boxes represent the quartile range, the upper whisker represents the third quartile plus 1.5 times the interquartile range, and the lower whisker represents the first quartile minus 1.5 times the interquartile range. Open circles represent outliers..39 Figure 2.2 Representative time courses of Tsk (°C) (circles), Troost (°C) (black solid line), and Ta (°C) (gray solid line) for (A) one bat in the control enclosure and (B) one bat in the heated enclosure during one of my 24-hour trials on 18-19 August 2016………………………………………………………………………………46 Figure 2.3: Scatter plot of the relationship between daily average Troost (°C) and normothermy index for 15 little brown bats in heated (black circles) and control (gray circles) flight enclosures. Data points are coloured by Troost treatments for illustration but heated vs. control treatment was not included in the model. A linear regression line is also included for illustration although data were analysed using a mixed effects model (see results)………………………………………..47 Figure 2.4: Histograms of (A) un-transformed intensity of infection (i.e., proportion of the wing covered with UV powder), and (B) logit-transformed intensity of infection for 15 little brown bats during environmental-substrate transmission infection experiment……………………………………………………………..50 Figure 2.5: Scatter plot of the relationship between normothermy index and intensity of infection (proportion of wing covered by proxy pathogen) for 15 little brown bats in heated (black circles) and