Nevada Department of Wildlife Hunt Unit O72
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FINAL RESEARCH REPORT JARBIDGE ELK HERD HABITAT EVALUATION: NEVADA DEPARTMENT OF WILDLIFE HUNT UNIT O72 By Jeffrey L. Beck, Ph.D. James M. Peek, Ph.D. Department of Fish and Wildlife Resources University of Idaho Moscow, Idaho 83844 January 2004 ii STUDY SUPPORTERS Cover photo of elk in the East Fork of the Jarbidge River drainage provided by Merlin McColm, Elko, Nevada. Photo from an original oil painting by Brent Todd, Salt Lake City, Utah. Suggested Citation: Beck, J. L., and J. M. Peek. 2004. Jarbidge elk herd habitat evaluation: Nevada Department of Wildlife hunt unit 072. Final research report. Department of Fish and Wildlife Resources, University of Idaho, Moscow, Idaho, USA. 172 pp. iii ABSTRACT Our primary research objective was to develop an elk carrying capacity model to estimate population levels that would not impair rangeland productivity in the Jarbidge Mountains of northeastern Nevada. Fieldwork was critical to obtain baseline data for model parameters such as habitat use and availability, diet composition, and forage nutrient abundance. Ninety-three elk were translocated into the Jarbidge Mountains in the 1990s; this population exhibited high growth rates and is predicted to increase to 1,110 by 2008. We evaluated production, species richness, and use of herbage standing crop in and outside exclosures across 3 seasons to better understand the effects of grazing by cattle and elk on mountain meadows in northeastern Nevada. Forbs declined throughout summer and total use clipping treatments in early and mid-summer resulted in low regrowth of forbs. We determined cattle, domestic sheep, elk, and mule deer diets with microhistological fecal analysis. Summer elk diets were largely composed of forbs. Diet group means did not differ between elk in spring with sheep in summer, elk in summer with deer and sheep, and cattle with sheep in summer. Twelve common forage species formed 44.2 to 85.3% of elk, deer, cattle, and sheep diets. We estimated crude protein (CP), digestible energy (DE) and macrominerals in 12 common forage species to assess whether nutrient levels met summer seasonal lactating cow elk requirements. Crude protein and DE decreased in herbs and woody browse across summer seasons and CP in lupines and snowbrush ceanothus provided reliably high levels of CP across all seasons. The most limiting nutrient to lactating cows was DE. Logistic regression modeling provided strong evidence in support of water and forage availability influencing elk habitat selection. We incorporated regression coefficients into iv resource selection functions (RSFs), or probabilities proportional to elk habitat use. We used RSFs to redistribute economic nutritional carrying capacity (INCC) estimates at 2 energetic performance levels for 236-kg lactating cow elk in autumn 1999 and 2000 over the summer range and then accordingly readjusted INCC estimates. Unadjusted INCC estimates predicted elk use of aspen and sagebrush–herb communities above nutritional resources at both performance levels in both years. v ACKNOWLEDGEMENTS We thank field technicians Jake Bieker, Jesse Lewis, Lara Peterson, Carl Rudeen, and Kate Smolski for their hard work, insights, and assistance in data collection. Don Klebenow, Bob McGinty, and Don Noorda were capable volunteers. Don King, a retired U.S. Fish and Wildlife Service fisheries biologist whose work toward restoring abundant populations of elk to Nevada ranges was an inspiration. Don went out of his way to ensure many aspects of the project in Nevada were organized and ran smoothly. Eva Strand, College of Natural Resources GIS and Remote Sensing Lab, University of Idaho, provided exceptional help with geographic analyses and software. We thank Dale Everson, Oz Garton, Ken Newman, Kirk Steinhorst, and Chris Williams, all University of Idaho, for their help with quantitative questions. Several graduate students provided helpful statistical explanations including Ann Abbott, Jeff Manning, and Deb Montgomery. Karen Launchbaugh, University of Idaho, and Bruce Davitt, Washington State University, provided use of their lab facilities for nutritional analyses. John Cook, National Council for Air and Stream Improvement, Incorporated, offered many insights on elk nutritional ecology. Mark Boyce, University of Alberta, provided helpful comments on habitat modeling. Steve Brunsfeld, College of Natural Resources Herbarium, University of Idaho, verified plant voucher specimens. Elsie Watson provided a thorough proofread. Karla Makus, Linda Kisha, and Delaine Hawley of the Department of Fish and Wildlife Resources, University of Idaho, were particularly helpful with clerical needs. Forest Service employees Dave Aicher, Will Amy, Fred Frampton, Jay Frederick, Cathy Jean, Teri Haney, Cheri Howell, Mike McNeil, Dave Prevedel, John Speck, and Bonnie Whalen; Nevada Division of Wildlife employees Larry Barngrover, Larry Gilbertson, vi and Joe Williams; and Bureau of Land Management employees Jim Klott, Ray Lister, and Ken Undlin all provided assistance at various times during our study. It was our privilege to interact with the insightful and supportive ranchers from the 71 Livestock Association, including Bert Brackett, Chet Brackett, Ira Brackett, Jarod Brackett, Marc Brackett, Kevin Chapin, Maurice Guerry, Mike Guerry, Charlie Liesen, and Randall Brewer. USDA Humboldt-Toiyabe National Forest, Nevada Division of Wildlife (now Nevada Department of Wildlife), USDI Bureau of Land Management, Rocky Mountain Elk Foundation, National Fish and Wildlife Foundation, Nevada Bighorns Unlimited, Elko Bighorns Unlimited, Safari Club International, the Cooperative Fish and Wildlife Research Unit, and the College of Natural Resources, University of Idaho supported our research. vii TABLE OF CONTENTS STUDY SUPPORTERS . ii ABSTRACT . iii ACKNOWLEDGEMENTS . v TABLE OF CONTENTS . vii LIST OF TABLES . xii LIST OF FIGURES . xvi EXECUTIVE SUMMARY . xix Chapter 1. Elk Population Characteristics, Nevada Division of Wildlife Hunt Unit 072, 1990–2003 . xix Abstract . xix Objective . xix Findings and Implications . xx Chapter 2. Herbage Productivity and Ungulate Use of Northeastern Nevada Mountain Meadows . xx Abstract . xx Objectives . xxi Findings and Implications . xxi Chapter 3. Elk, Mule Deer, Cattle, and Domestic Sheep Diet Relationships on Arid Montane Summer Range . xxi Abstract . xxi Objectives . xxii Findings and Implications . xxii Chapter 4. Nutrient Evaluation for Elk Forages on Northeastern Nevada Summer Range . xxiii Abstract . xxiii Objectives . xxiv Findings and Implications . xxiv Chapter 5. Habitat Use Constraints on Elk Summer Nutritional Carrying Capacity Estimates . xxiv Abstract . xxiv Objectives . xxvi Findings and Implications . xxvi viii Appendix 1. Elk Habitat Availability Map: Development and Accuracy Assessment . xxvi Abstract . xxvi Appendix 2. Summer Nutritional Carrying Capacity Model for Elk in the Jarbidge Mountains, Nevada . xxvii Abstract . xxvii CHAPTER 1. ELK POPULATION CHARACTERISTICS, NEVADA DIVISION OF WILDLIFE HUNT UNIT 072, 1990–2003 . 1 INTRODUCTION . 1 STUDY AREA . 4 METHODS . 5 Summer Elk Population Composition . 5 Nevada Division of Wildlife Elk Population Monitoring . 6 RESULTS AND DISCUSSION . 8 Summer Elk Population Composition . 8 Winter Elk Population Composition . 9 Elk Hunting . 11 Population Estimates and Growth Rates . 12 LITERATURE CITED . 14 CHAPTER 2. HERBAGE PRODUCTIVITY AND UNGULATE USE OF NORTHEASTERN NEVADA MOUNTAIN MEADOWS . 23 INTRODUCTION . 23 STUDY AREA . 25 Black Spring . 27 Monument Spring . 28 Sagehen Spring . 28 METHODS . 29 Exclosure Experimental Design . ..