THE CONSERVATION MANAGEMENT AND ECOLOGY OF NORTHEASTERN NORTH AMERICAN BUMBLE BEES AMANDA LICZNER A DISSERTATION SUBMITTED TO THE FACULTY OF GRADUATE STUDIES IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY GRADUATE PROGRAM IN BIOLOGY YORK UNIVERSITY TORONTO, ONTARIO September 2020 © Amanda Liczner, 2020 ii Abstract Bumble bees (Bombus spp.; Apidae) are among the pollinators most in decline globally with a main cause being habitat loss. Habitat requirements for bumble bees are poorly understood presenting a research gap. The purpose of my dissertation is to characterize the habitat of bumble bees at different spatial scales using: a systematic literature review of bumble bee nesting and overwintering habitat globally (Chapter 1); surveys of local and landcover variables for two at-risk bumble bee species (Bombus terricola, and B. pensylvanicus) in southern Ontario (Chapter 2); identification of conservation priority areas for bumble bee species in Canada (Chapter 3); and an analysis of the methodology for locating bumble bee nests using detection dogs (Chapter 4). The main findings were current literature on bumble bee nesting and overwintering habitat is limited and biased towards the United Kingdom and agricultural habitats (Ch.1). Bumble bees overwinter underground, often on shaded banks or near trees. Nests were mostly underground and found in many landscapes (Ch.1). B. terricola and B. pensylvanicus have distinct habitat characteristics (Ch.2). Landscape predictors explained more variation in the species data than local or floral resources (Ch.2). Among local variables, floral resources were consistently important throughout the season (Ch.2). Most bumble bee conservation priority areas are in western Canada, southern Ontario, southern Quebec and across the Maritimes and are most often located within woody savannas (Ch.3). Climate change is predicted to shift priority areas to more northerly latitudes and to higher elevations (Ch.3). These priority areas do not overlap highly with current protected areas (Ch.3). Using detection dogs to locate the scent of bumble bee nests was more nuanced than expected (Ch.4). The detection distance for nests was short, so dogs needed to conduct detailed searches for nests (Ch.4). Nests may also have iii multiple entrances which complicates confirming detections made by dogs (Ch.4). The challenges with deploying detection dogs to locate bumble bee nests could be mitigated with careful study design should be carefully considered in future research. This research addresses many gaps in our understanding of bumble bee habitats and will be valuable in informing conservation policy. iv Acknowledgements I would like to thank my family and friends, particularly my husband Dr. Alex Filazzola for supporting me throughout my dissertation. Thank you to my parents for trying to understand this whole graduate student thing and being supportive of me through this journey. Alex, I would not have made it this far without you. Your support got me through the lowest low points and celebrated with me through the highest highs. Thank you for your help with everything from field work; to holding a bumble bee that is for sure a male and can’t sting (well I was pretty sure it was a male); to helping with R spatial statistics and functions and super computing; editing various documents; and for always being an emotional rock and believing in me when I didn’t believe in myself. You are still, and always will be, my favourite field assistant. I would also need to thank my amazingly supportive supervisor Dr. Sheila Colla who introduced me to the bumble bee world before I knew anything (!) about bumble bees. Thank you for giving me the space to learn, your compassion and understanding, wealth of knowledge, laughing at my sarcastic jokes, and helping me fund expensive and cool projects. I’m so glad you took a chance on me, and I owe much of my positive experience during my PhD to you. Similarly, I would like to thank my supervisory committee members Dr. Bridget Stutchbury and Dr. Dawn Bazely for your support over the last four years and all your helpful advice during progress reports. Also thank you for the many reference letters you both wrote for me over the years. I could not have asked for a more supportive committee. Thank you to Dr. Laurence Packer, Dr. Justin Podur, and Dr. Jessica Forrest for serving on my defense committee. To all my fantastic lab members, thank you! Your help acting as a sound boards, or offering kind words, and laughing at my jokes and shenanigans livened up the lab space and made it such a wonderful working environment. Specifically thank you to Victoria MacPhail, Shelby Gibson, Sarah MacKell, Hadil Elsayed, Melina Damian and Briann Dorin. A special thank you to Sarah Johnson and Genevieve Rowe whose work with Wildlife Preservation Canada was extremely beneficial to my dissertation. Your willingness to help with anything I needed was always much appreciated. I would also like to thank my co-authors for their hard work in the field, with statistics, and especially with manuscript revisions: Dr. Richard Schuster, Dr. Leif Richardson, Dr. Ngaio Richards, Dr. Deborah A. (Smith) Woollett. A big thank you to my field assistants over the years including Kurt Ramos, Jenny Tang, Dr. Alex Filazzola, Melina Damian, Camilla Gillis-Adelman, Stephen Humphrey, Dr. Rachel Nalepa, Junaid Khan, Sheila Dumesh, Dr. Laura Timms, Melissa Steen, Orbee, Tule, and Utah. I have spent all my university career at York University and have met many amazing people here that have contributed so much to my experience through the AGSBS, CoTL, teaching, course work or other activities including Dr. Robert Tsushima, Dr. Amro Zayed, Dr. Mark Vicari, Dr. Alex Mills, Dr. Nicole Nivillac, Dr. Julie Clark, Dr. Tamara Kelly, Dharti Patel, and Ming Jiang. v Table of Contents Abstract ........................................................................................................................................... ii Acknowledgements ........................................................................................................................ iv Table of Contents ............................................................................................................................ v List of Tables ............................................................................................................................... viii List of Figures ................................................................................................................................ ix Chapter 1: A systematic review of the nesting and overwintering habitat of bumble bees globally ......................................................................................................................................................... 1 Summary ..................................................................................................................................... 2 Introduction ................................................................................................................................. 3 Methods....................................................................................................................................... 4 Literature review ..................................................................................................................... 4 Data extracted ......................................................................................................................... 5 Data analysis ........................................................................................................................... 5 Results and Discussion ............................................................................................................... 7 Overwintering habitat ............................................................................................................. 7 Nesting habitats ..................................................................................................................... 10 Ground position and materials of bumble bee nests ............................................................. 13 Detecting bumble bee nests .................................................................................................. 16 Conclusions ............................................................................................................................... 19 References ................................................................................................................................. 20 Tables and Figures .................................................................................................................... 32 Chapter 2: One size does not fit all: at-risk bumble bee habitat management requires species- specific and local and landscape considerations ........................................................................... 40 Summary ................................................................................................................................... 41 Introduction ............................................................................................................................... 42 Materials and Methods .............................................................................................................. 45 Study species habitat ............................................................................................................