Grizzly bear population dynamics across productivity and human influence gradients by Clayton T. Lamb A thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Ecology Department of Biological Sciences University of Alberta © Clayton T. Lamb, 2019 Abstract Coexistence with large carnivores is one of the greatest conservation challenges across the globe, in part because mechanisms of coexistence are unknown or contested. Large carnivores can be conflict-prone and pose real or perceived threats to human life and property. In North America, grizzly bears (Ursus arctos) typify the struggle to conserve and coexist with large carnivores amongst a matrix of competing land uses. Grizzly bears are a symbol of wildness to society, but the management of this species can divide communities, derail collaborative conservation initiatives, and are the focus of high-profile media coverage and lawsuits. At the center of this controversy is scientific uncertainty around population dynamics of the species, primarily relating to population size, limiting factors, and the ecology of conflict. The contemporary threats of wilderness loss, human population expansion, and climate change pose both a no-analog future for grizzly bears, but also opportunity. Leveraging novel ecological tools, and the ongoing human-induced landscape and climate change, considerable opportunity exists to investigate the mechanisms driving grizzly bear population dynamics and those promoting coexistence—enduring populations of wildlife in human-dominated landscapes. The goal of this dissertation was to test the factors limiting grizzly bear population dynamics across ecosystems, update local population estimates, and to identify the mechanisms promoting carnivore coexistence and those exacerbating it. Here I leverage 40 years of demographic data on grizzly bears collected across ecosystems to investigate hypotheses around grizzly bear population dynamics across productivity and human influence gradients in British Columbia (BC). This work provides multiple lines of evidence that grizzly bear populations purportedly coexisting in human-dominated landscapes are highly reliant on demographic rescue (immigration) from adjacent wilderness areas. This source-sink dynamic is exacerbated when ii attractive habitat decouples the link between habitat quality and fitness, resulting in an ecological trap. Human influences such as human population density and road density have the potential to create strong, top-down limiting forces on bear populations that dwarf bottom-up influences. However, much of British Columbia is not permanently occupied by people, and the majority of grizzly populations across the province are more strongly bottom-up limited. Considerable potential exists to ensure the conservation and coexistence of bears is a success if evidence-based mitigation is executed collaboratively and equitably. I provide insight into the response of bear density to mitigation measures for reducing road density and highlight several cases where evidence from this dissertation lead to meaningful conservation actions that will benefit bears, a variety of wildlife inhabiting similar areas, and people. Collectively, this dissertation provides strong inference into the spatial structure and drivers of grizzly bear population dynamics across ecosystems and suggests that data generated for applied problems can be leveraged to test theory while informing conservation at massive spatial extents. iii Preface This dissertation is an original work by Clayton Lamb. The grizzly bear telemetry research projects, of which this dissertation is a part, received research ethics approval from the University of Alberta Research Ethics Board, “Rates and causes of grizzly bear mortality”, No. AUP00002181, June 14, 2017. Ethical approval for the analyses of the genetic tagging data used here was provided by the University of Alberta Research Ethics Office, December 2014 (Category A, non-invasive). Chapter 2: this chapter was published in Ecological Applications, March 2019: Lamb, C.T., Ford, A.T., Proctor, M., Royle, A.J., Mowat, G., Boutin, S. 2019. Genetic tagging in the Anthropocene: scaling ecology from alleles to ecosystems. Ecological Applications. 29(4): e01876. PDF Chapter 3: this chapter was published in Journal of Applied Ecology, January, 2018: Lamb, C.T., Mowat, G., Reid, A., Smit, L., Proctor, M., McLellan, B.M., Nielsen, S.E., Boutin, S. 2018. The effect of habitat quality and access management on the density of a recovering grizzly bear population. Journal of Applied Ecology 55(3): 1406-1417. PDF Chapter 5: this chapter was published in Journal of Animal Ecology, September, 2017: Lamb, C.T., Mowat, G., McLellan, B.M., Nielsen, S.E., Boutin, S. 2017. Forbidden fruit: Human settlement and abundant fruit create an ecological trap for an apex omnivore. Journal of Animal Ecology. 86(1): 55-65. PDF Three papers that support this dissertation were also published during Clayton Lamb’s PhD, but were not part of the core dissertation on population dynamics, and are not included in this document. The three papers can be found here: Lamb, C.T., Festa-Bianchet, M., Boyce, M.S. 2018. Invest long term in Canada’s wilderness. Science. 359(6379) pp. 1002. PDF Lamb, C.T., Walsh, D., Mowat, G. 2016. Factors influencing detection success of grizzly bears at genetic sampling sites. Ursus. 27(1): 31-44. PDF Lamb, C.T., G. Mowat, S. Gilbert, B.M. McLellan, S.E. Nielson, S. Boutin. 2017. Density- dependent signaling: An alternative hypothesis on the function of chemical signaling in a non-territorial solitary carnivore. PLoS ONE. PDF iv Acknowledgements One might say “It takes a village to raise a Ph.D.”, and my Ph.D. was no different. There are hundreds of people to thank for their contributions to my education and growth, ranging from administration staff in government and academia, dedicated environmental groups, industry leaders, field partners, my supervisors and lab mates, and of course family and friends. I will endeavor to share some of the contributions from individuals and groups who have continually supported, shaped, and mentored me through this process. My parents, Joanne and Rick, without your limitless love and support this would not have been possible. Thank you for introducing me to the wild. The intricacies and beauty of nature’s flora and fauna are reserves of energy and joy for me. The time we spent in Renfrew, on the banks of the Vedder River, or the Kettle Valley facilitated a deep connection to the land and water, and an opportunity to learn and develop on my own. You have always wholly encouraged me to pursue my passions, whatever they may be, and to be continually learning and growing. My success as a person and professional stem from your continued investment in my happiness, wellbeing, character, and skills. Love you guys, always. My University supervisors, Stan and Scott, thank you for pushing me to do better while providing unwavering support for me and my education. You both gave me the space to pursue my interests and live a lifestyle that was sustainable for me during my Ph.D., while always being there at a moment’s notice to offer advice, ideas, or much-needed manuscript edits. My time spent with you shaped my ability to test and understand ecological processes at both small and large extents and set a high bar for scientific veracity. Melanie Dickie was essential in helping me finish this dissertation as she helped me coerce this document into the very strict submission format of PDF/A, which my Mac was not v interested in doing. Such investment from Mel is actually part of >5 years of friendship and professional collaboration. Thanks, Mel, and all of the Boutin, Nielsen, Boyce, Merrill, and Derocher lab members for your support and motivation over the years. A special thanks to Adam Ford, who was not officially on my committee but has played a large role in my academic and professional development in the latter half of my Ph.D. A first encounter at a Revelstoke bar produced banter about Resource Selection Functions and the capacity of wild animals to detect ecology in elevation rasters, and has since developed into a strong and collaborative relationship that I look forward to continuing. My non-University supervisors, primarily Garth, but also Bruce and Michael, you guys collectively shared with me nearly a century of knowledge about bears, their ecology, management, and how to catch them. Further, your enduring commitment to evidence and strong inference (like my University supervisors) shaped my ability to do science and think critically. Thank you for encouraging me to start a large-scale collaring program mid-PhD, this endeavor has yielded more academic, applied, and personal benefits than I could have imagined. Thanks to Bruce and Michael for shacking up in a small Elkford apartment with me and being there to teach me how to safely, ethically, and effectively capture and collar the first grizzly bears on the Elk Valley project. Thanks to Garth for your lasting investment in me, which started in 2013 before I began my Ph.D. and continues to this day. When I needed a spot to stay your family was always welcoming (sometimes for months! Lots of great cheeses were had), when money dried up you always seemed to find a reserve, and you were always approachable and insightful when I needed to resolve scientific or professional uncertainties. My field partners, especially Laura S, Laura G, and Dusty, thanks for your optimism, humor, organization, and skills in some of the best and most adverse situations outside. Laura S, vi you have been a keystone in keeping Garth and I from surely losing all of our gear, data, and forgetting to pay bills or order field supplies on time. But more than that, thanks for your enthusiasm and dedication to being a part of our team, I don’t know what we’d do without you. I reluctantly admit that you might be a better bear trapper than I am.