Grizzly Bears and Humans at Two Moth Aggregation Sites in Wyoming
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GRIZZLY BEARS AND HUMANS AT TWO MOTH AGGREGATION SITES IN WYOMING by Erika Ana Nunlist A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Animal and Range Science MONTANA STATE UNIVERSITY Bozeman, Montana May 2020 ©COPYRIGHT by Erika Ana Nunlist 2020 All Rights Reserved ii DEDICATION I dedicate this thesis to Fred Thomas and his wife Kay. Fred is a multi- generational Wyoming rancher with an unusual bear problem, a reputation that preceded him. As soon as I mentioned my southern study site folks throughout Park County would say, “Have you met Fred yet?” Well, I finally met Fred and we hit it off. He has spent a lifetime at our southern study site watching the bears and climbing the peak. He provided valuable insight only someone who has climbed the peak as many times as he has could. If the area needed to be renamed, I believe “Fred’s Shangri-La” would be suitable. He has shared videos and pictures with me, he and Kay have fed me many dinners, taken me mountain lion hunting. Thank you, Fred and Kay! iii ACKNOWLEDGEMENTS This project would not have been possible without contributions from many entities. First and foremost, thank you to the Greater Yellowstone Coordinating Committee for providing funding for this project. Thank you to the capable staff on the Shoshone National Forest for your logistical and tactical support. Thank you Dan Tyers (USFS) and Andrew Pils (USFS) for developing this project and giving me the opportunity to run it. Thank you to Montana State University, Departments of Animal and Range Sciences and Ecology, for providing the additional resources. Thank you, Bok Sowell, my advisor, for focusing my thinking and helping me navigate all aspects of this project. Thank you, Jesse DeVoe for help with analyses. Thank you to Dick and Mary Ohman and Gerry Bennett for your generous financial support. Thank you to these Forest Service Employees for your advocacy for this project: Rob Harper, Washington Office Wildlife, Fish and Rare Plants Program Leader; Joe Alexander, former Shoshone Forest Supervisor; Peter McDonald, Forest Service Region 2 Threatened, Endangered, and Sensitive Species Coordinator. The same note of thanks goes to the Greater Yellowstone Coordinating Committee executive managers for prioritizing this project and sustaining interest and support. Thank you to John Squires and Lucretia Olson, Forest Service Rocky Mountain Research Station, and Scott Jackson, National Carnivore Program Leader, for providing important equipment. Thank you to Fred and Kay Thomas for the photos, videos, and local knowledge you contributed to this project. Thank you to Emma Grusing, Steven Cross, Aaron O’harra, Abigail Lake, and Tom Henning-Linden for being all-star technicians. Thank you to my parents for your continual support. And thank you to my partner James Waxe for everything you do. iv TABLE OF CONTENTS 1. LITERATURE REVIEW ................................................................................................1 Army Cutworm Moth Life History and Alpine Aggregations.........................................1 Grizzly Bears and the Importance of Moth Sites .............................................................5 Bear Viewing Tourism, Human Use at Moth Sites, and Management Concerns ..........10 Project Justification in the Greater Yellowstone Ecosystem .........................................16 2. GRIZZLY BEARS AND HUMANS AT TWO MOTH AGGREGATION SITES IN WYOMING ..................................................................................................18 Introduction ....................................................................................................................18 Study Area .....................................................................................................................22 Methods..........................................................................................................................24 Bear Use .................................................................................................................24 Human Use.............................................................................................................34 Human and Bear Use Overlap and Interactions .....................................................40 Results ............................................................................................................................41 Season Efforts ........................................................................................................41 Bear Use .................................................................................................................42 Human Use.............................................................................................................63 Human and Bear Use Overlap and Interactions .....................................................70 Discussion ......................................................................................................................74 Bear Use .................................................................................................................74 Human Use.............................................................................................................83 Human and Bear Use Overlap and Interactions .....................................................87 3. SUMMARY AND MANAGEMENT RECOMMENDATIONS ..................................91 Summary ........................................................................................................................91 Management Recommendations ....................................................................................94 REFERENCES CITED ......................................................................................................96 APPENDICES .................................................................................................................103 APPENDIX A: Evaluation of Pooled RSF Model ..............................................104 APPENDIX B: Plant Samples Collected Opportunistically in 2018 ...................108 v LIST OF TABLES Table Page 1. Covariates considered and developed for RSF model development, organized by suite, detailing hypothesized relationships, spatial grains and functional forms considered, supporting literature, and covariate development .....................................................................................29 2. Landscape layer processing for the human accessibility model. Road, trail, and campsite layers were obtained from the Shoshone National Forest. All other layers were obtained from the USDA or Wyoming GIS clearinghouse ............................................................................................36 3. Mean elevation and standard deviation (SD) of all confirmed moth sites in the GYE ...............................................................................................51 4. Results from our first RSF model selection tier of univariate models. Spatial grain(s) and functional form(s) ranked <4 ∆AICc for each covariate are listed. See Table 1 for covariate descriptions .............................53 5. Results from our second RSF model selection tier of competing univariate models and top within-suite models. Models ranked <4 ∆AICc within each suite are listed. Within and across suite model results are listed. Results are arranged by within suite AICc ranking. The number of parameters (K) and AICc weight (wti) are also presented. See Table 1 for covariate descriptions ..............................54 6. Results from our final RSF model selection tier of top models. Models ranked <4 ∆AICc reported and arranged by AICc ranking. The number of parameters (K) and AICc weight (wti) are also presented. See Table 1 for covariate descriptions. ...........................................55 7. Bear scat diet analysis of scats collected at the North and South sites in 2017 and 2018. Frequency (%) and volume (%) of each diet item across all scats are listed ...................................................................62 8. Trailhead monitoring efforts and observed vehicle and hiking activity at the North and South sites in 2017 and 2018 ...................................66 9. Primary reason(s) for visitation for hiking groups at the North and South site in 2017 and 2018 ............................................................................67 vi LIST OF FIGURES Figure Page 1. Army cutworm moth range, North America, adapted from Burton et al. (1980) ...................................................................................2 2. Army cutworm moth life history, taken from White (1996), originally modified from Kendall (1981) ..........................................................2 3. Grizzly bear range, demographic monitoring area, and recovery zone in the Greater Yellowstone Ecosystem, North America. Taken from Bjornlie and Haroldson (2018)..................................................................6 4. Study areas (North and South site) within the Shoshone National Forest in the Greater Yellowstone Ecosystem, North America .......................23 5. All of our bear location data (survey and opportunistic) collected at the South site in 2017 and 2018 ...................................................................43 6. All of our bear location data (survey and opportunistic) collected at the North site in 2017 and 2018 ...................................................................44 7. Total