University of Montana ScholarWorks at University of Montana Graduate Student Theses, Dissertations, & Professional Papers Graduate School 1979 Bear-livestock interactions Targhee National Forest Carole J. Jorgensen The University of Montana Follow this and additional works at: https://scholarworks.umt.edu/etd Let us know how access to this document benefits ou.y Recommended Citation Jorgensen, Carole J., "Bear-livestock interactions Targhee National Forest" (1979). Graduate Student Theses, Dissertations, & Professional Papers. 6758. https://scholarworks.umt.edu/etd/6758 This Thesis is brought to you for free and open access by the Graduate School at ScholarWorks at University of Montana. It has been accepted for inclusion in Graduate Student Theses, Dissertations, & Professional Papers by an authorized administrator of ScholarWorks at University of Montana. For more information, please contact [email protected]. BEAR-LIVESTOCK INTERACTIONS, TARGHEE NATIONAL FOREST by Carole Jorgensen B.S., University of Montana, 1975 Presented in partial fulfillment of the requirements for the degree of Master of Science UNIVERSITY OF MONTANA 1979 Approved by: Chairman ^^oard of Examiners Dean, Graduate School Date Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. UMI Number: EP37559 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. UMI* Ois*«rtatiori Publishing UMI EP37559 Published by ProQuest LLC (2013). Copyright in the Dissertation held by the Author. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code Pro.Q^st* ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 4 8 1 0 6 -1 3 4 6 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Jorgensen, Carole J., M.S., June 1979 Wildlife Biology Bear-livestook Interactions, Targhee National Forest ( 162 pp) Director: Charles J. Jonkel Black bear (Ursus americanus), grizzly bear (_U. arctos), and domestic sheep interactions and competition were investigated using radio telemetry on the Targhee National Forest in Idaho and Wyoming during 1976 and 1977 to better determine the role of bears within Multiple Use (Multiple Use Act, 1964) areas. Black and grizzly bear intra— and interspecific relationships were discussed in terms of habitat utilization and food habits. Radio-monitored movements of seven black bears and one grizzly were compared to movements of sheep herds on selected USFS sheep allotments to investigate bear behavior near sheep herds and determine the extent of competition and inter­ specific conflicts. Competition between bears and sheep occurred when they utilized the same plants (primarily grasses and forbs) that were limited by either abundance or seasonal availability. Additional conflict, resulting in losses of sheep to bear predation and high bear mortality from real or alleged predation, occurred during concurrent habitat use by bears and sheep. Bear predation was discussed in detail. Areas and seasons of expected bear—sheep interaction were delineated. Management to possibly alleviate some bear-sheep conflict was discussed. 11 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ACKNOWLEDGEMENTS Thank God ! I would like to express my gratitude to Drs. Bart O'Gara and Lee Eddleman for serving on my committee and for providing me with expert advice and encouragement. I am especially grateful to my major advisor, Dr. Charles Jonkel, for his extraordinary patience, encouragement, and financial and technical assistance. I also wish to thank Dr. Sara Jane Johnson and the Targhee National Forest for initia­ ting the study and for financial assistance. This study would not have been possible without the additional assistance from the Border Grizzly Groject, headed by Charles Jonkel; Dick Knight and the Inter-agency Grizzly Bear Study Team; Rick Phillips and Rich Wonnecot of the U.S. Fish and Wildlife Service; as well as the Idaho Fish and Game and Wyoming Game and Fish departments. Appre­ ciation is extended to the permittees on the study area— especially Ross and Sam Davis and their herders for their cooperation. Not to be forgotten are; Roy Hugie for technical and academic assistance, John Beecham for analytical and trapping expertise, and Coy Miller for his engineering wizardry. A special thanks to Maurice Hornocker for his good faith and effective persuasion and to the many people who provided me with field assistance and data collection. Many thanks to Ruthann Brier for her patience and expertise in typing this manuscript. Finally, acknowledgements to my mother, Evelyn Jorgensen, who never waivered in her belief in me. iii Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. TABLE OF CONTENTS Page ABSTRACT ............................................................. ±± ACKNOWLEDGEMENTS .................................................... iii LIST OF TABLES ...................................................... vi LIST OF FIGURES ................................................... vii CHAPTER I. INTRODUCTION ................................................. 1 History of Sheep and Predators on the Targhee .... 3 Bear Predation ............................................ 5 Predator Control .......................................... 6 Range U s e ................................................. 8 Bear/Livestock Food Competition ....................... 9 O b j e c t i v e s ................................................. 10 II. STUDY A R E A ................................................... 12 III. METHODS AND MATERIALS ..................................... 18 Capture and Tagging Techniques .......................... 18 Radio Monitoring ................................... 20 Grizzly Study Methods and Materials ................... 20 Home Range Methods ........................................ 21 Habitat U s e ............................................... 21 Bear Mortality Investigation ............................ 22 Bear and Sheep Food Competition ....................... 22 S t a t i s t i c s ................................................. 24 IV. RESULTS AND DISCUSSION ..................................... 25 Bear D a t a ................................................. 25 Home Range D a t a .......................................... 27 Intraspecific Behavior ................................... 38 Black Bear Sightings .............. 41 Grizzly Bear Sightings ................................... 44 Yellowstone Study Team Grizzlies (IGBST) .............. 44 Grizzly Bear Home Ranges ................................. 47 Grizzly Bear/Black Bear Interactions ................... 48 Habitat Description ...................................... 51 Description ............................................. 51 Habitat occurrence ...................................... 52 USFS cover types ........................................ 54 ■Iv Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. V CHAPTER PAGE Use by b e a r s ............................................... 55 Differences in black bear and grizzly bear habitat use ........................................ 56 Bear food h a b i t s ......................... 57 Stomach contents ................................... 61 Seasonal food utilization ................................. 61 Sheep use of h a b i ta t ..................................... 64 Bear and Sheep Food Competition In d e x ...................... 66 Sheep use ratings .......................................... 67 Utilization by bears (derived from the literature) . 67 P r e d a t i o n ............................ .... ..................... 71 Determination of predation by bears ...................... 76 Justification Based on Stomach Contents ................... 80 Herders as a Factor in Bear Depredation and M o r t a l i t y ................................................... 82 Sheep Losses ........................................ 84 USFWS bear mortality ..................................... 86 Salvage of B e a r s ............................................ 89 Summary of Bear Mortality by Sheepmen ..................... 90 Bear/Sheep Interactions ..................................... 96 D i s c u s s i o n ....................... .. ....................... 121 Intraspecific Relationships Among Depredating Bears . 126 Competition: Bears and Sheep .............................. 128 V. CONCLUSIONS ............................................................ 131 VI. SUMMARY ................................................................ 138 REFERENCES CITED ........................................................ 142 APPENDIX A. BEAR FOOD/SHEEP F O O D ................................................ 154 B. TRAPPING SUMMARY ..................... 159 C. ALLOTMENT UNIT BOUNDARIES ........................................... 161 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. LIST OF TABLES Table Page 1. Summer home ranges of collared black bears, 1976-1977 .... 28 2. Mean distances between