Utah State University DigitalCommons@USU All Graduate Theses and Dissertations Graduate Studies 5-2017 The Behavior and Ecology of Cursorial Predators and Dangerous Prey: Integrating Behavioral Mechanisms with Population-level Patterns in Large Mammal Systems Aimee Tallian Utah State University Follow this and additional works at: https://digitalcommons.usu.edu/etd Part of the Population Biology Commons Recommended Citation Tallian, Aimee, "The Behavior and Ecology of Cursorial Predators and Dangerous Prey: Integrating Behavioral Mechanisms with Population-level Patterns in Large Mammal Systems" (2017). All Graduate Theses and Dissertations. 5629. https://digitalcommons.usu.edu/etd/5629 This Dissertation is brought to you for free and open access by the Graduate Studies at DigitalCommons@USU. It has been accepted for inclusion in All Graduate Theses and Dissertations by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. THE BEHAVIOR AND ECOLOGY OF CURSORIAL PREDATORS AND DANGEROUS PREY: INTEGRATING BEHAVIORAL MECHANISMS WITH POPULATION-LEVEL PATTERNS IN LARGE MAMMAL SYSTEMS by Aimee Tallian A dissertation submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY in Ecology Approved: __________________________ __________________________ Daniel R. MacNulty Eric M. Gese Major Professor Committee Member __________________________ __________________________ Kari E. Veblen R. Douglas Ramsey Committee Member Committee Member __________________________ __________________________ Trisha B. Atwood Mark R. McLellan Committee Member Vice President for Research and Dean of the School of Graduate Studies UTAH STATE UNIVERSITY Logan, Utah 2017 ii Copyright © Aimee Tallian 2017 All Rights Reserved iii ABSTRACT The Behavior and Ecology of Cursorial Predators and Dangerous Prey: Integrating Behavioral Mechanisms with Population-level Patterns in Large Mammal Systems by Aimee Tallian, Doctor of Philosophy Utah State University, 2017 Major Professor: Dr. Daniel MacNulty Department: Wildland Resources The study of predator-prey behavior is of primary importance to the field of ecology. However, few studies measure interactions between predators and their most dangerous prey. The objective of this project was to improve understanding of the behavioral and ecological interactions between cursorial predators and dangerous prey in free-living systems. Specifically, I used data from Yellowstone National Park to evaluate 1) the role of cooperative hunting in the ability of predators to hunt dangerous prey, 2) how predator preference for differentially dangerous prey species changes in relation to their relative abundance, 3) the ability of cursorial predators to drive large-scale, landscape level shifts in prey habitat use, and 4) how the kill rate of a top predator was affected by the presence of another. In chapter 2, I found that wolves (Canis lupus) were more cooperative when hunting bison (Bison bison), their most dangerous prey, than when hunting elk (Cervus elaphus). The results from iv chapter 3 suggest that wolves in northern Yellowstone attacked and killed disproportionately more of the rarer, but safer prey species; wolves maintained a strong preference against bison, even when this species was more than twice as abundant as elk. Analyses of wolf-bison behavioral interactions indicate that wolf preference against bison likely reflected an inability to consistently overcome bison antipredator defenses. Chapter 4 presents several lines of evidence suggesting wolves are a plausible mechanism behind recent decreased bison preference for Yellowstone’s high elevation winter range. For example, bison preference for the high elevation Pelican Valley region decreased after wolf reintroduction. This preference was strongly influenced by snow-cover, a proxy for predation risk. In Chapter 5, I collaborated with Scandinavian ecologists to determine how wolf kill rate was affected by a sympatric apex predator, the brown bear (Ursus arctos). My results suggest brown bear presence resulted in wolves killing less frequently in both Scandinavia and Yellowstone. My research contributes to the current body of work addressing the effects of wolf reintroduction in Yellowstone, and sheds light on the behavioral relationships at play in a special type of predator-prey interaction: predators that hunt dangerous prey. (247 pages) v PUBLIC ABSTRACT The Behavior and Ecology of Cursorial Predators and Dangerous Prey: Integrating Behavioral Mechanisms with Population-level Patterns in Large Mammal Systems Aimee Tallian Driving into Yellowstone National Park for the first time is a moving experience. Gazing over the sweeping landscapes, seeing a geyser erupt 80 feet into the air, and having your first ‘wildlife encounter’, whether that be a 2 ton bull bison aggressively wallowing on his dirt mound, snorting and kicking up dust, or watching a pack of 6 wolves move through a valley off in the distance, pausing to howl in search of their companions. Yellowstone staff wishes to manage our park in a way that preserves these remarkable experiences. In order to effectively manage this dynamic ecosystem, it is critical to thoroughly understand how different animal and plant species interact with each other and their environment. Wolves were reintroduced to Yellowstone in 1995-1997 and park researchers and managers are still trying to understand how their presence impacts the ecosystem. In Yellowstone, wolves primarily prey on elk; however, predation on bison has started to increase in recent years. We still know little about how wolves hunt bison and what impacts wolves have had on how bison use their environment. The objective of this study was to better understand the behavioral and ecological interactions of wolves and bison, the most dangerous prey for wolves in North America. Since vi reintroduction, researchers have collected data on how wolves hunt both elk and bison. I used these data to understand 1) the conditions that allow wolves to capture their most dangerous prey, bison, 2) whether wolves have started preying on bison more often as the bison population increased, and 3) whether wolf reintroduction has limited bison use of Yellowstone’s most extreme high-elevation winter range. Finally, I collaborated with ecologists in Scandinavia to determine how wolf predation was affected by a competitor, the brown bear. My study adds to the current body of work addressing the effects of wolf reintroduction in Yellowstone. This research is unique because it focuses on wolf- bison interactions, about which little is known in this system. This research also sheds light on the behavioral relationships at play in a special type of predator-prey interaction: predators that hunt dangerous prey. vii ACKNOWLEDGMENTS I first met Dr. Dan MacNulty on a hilltop in Pelican Valley in March, 2010. Travis Wyman asked me to ski into the valley with him on a resupply trip for the ongoing project that would ultimately become the focus of my dissertation. The morning after our long ski into the field site, and my first of many nights sleeping on the snow in a cold tent, the Mollies pack moved into the valley and targeted a bull bison. The hunt lasted most of the day; we watched as the wolves took turns attacking and harassing the old bull, until it finally succumbed late that evening. It was an incredible experience to witness such an interaction, especially on my first day in the valley, and I wanted to see more. With Travis’s encouragement, I phoned Dan several months later to ask about the project. His enthusiasm for wolves, bison, and the Pelican Valley system was more than contagious, which has been the theme of our collaboration ever since. Dan’s help, guidance, support, and belief in me is the foundation of this work, thank you. Dan and Travis seamlessly incorporated me into their crew and showed me the wily ways of Pelican, for which I cannot thank you both enough. Many thanks go to my committee members, Drs. Trisha Atwood, Eric Gese, Douglas Ramsey and Kari Veblen for their help and support. Countless employees and students at Utah State University have helped me along the way. I would like to thank the Animal Ecology Lab, especially Dr. Lise Aubry, Dr. Johan Du Toit, Ryan Kindermann, Daniel Kinka, Michel Kohl, Peter Mahoney, Jarod Raithel, Dustin Ranglack, Joel Ruprecht, and Dr. Julie Young for all of the discussions, statistical viii guidance, manuscript revisions, and general help. I would not have gotten through it without you guys. To my other friends in Logan who provided so much support, Antra Boca, Julie Kelso, and Kerry Shea, thank you. I would like to thank Susan Durham, whose statistical help got me over countless hurdles, for her help and patience. Thanks also to the two women who keep our department running, Marsha Baily and Lana Barr. I would especially like to thank my collaborators in Yellowstone National Park, Matthew C. Metz, and Drs. Douglas W. Smith, Daniel R. Stahler, P.J. White, Rick Wallen and Chris Geremia. We have known each other for many years, and it has truly been a pleasure to work with them in this new capacity. I also give special thanks to my collaborators in Scandinavia: Cyril Milleret and Drs. Jonas Kindberg, Andrés Ordiz, Håkan Sand, Jon E. Swenson, Petter Wabakken, and Camilla Wikenros. Their help and guidance resulted in a collaboration that was truly a highlight of my graduate school experience. I would like to thank the numerous people that have participated