SPECIES ASSESSMENT FOR GRIZZLY (B ROWN ) BEAR (URSUS ARCTOS ) IN WYOMING prepared by 1 1 2 MELISSA REED -ECKERT , CARRON MEANEY , AND DR. GARY P. BEAUVAIS 1 Meaney & Company, 777 Juniper Avenue, Boulder, Colorado 80304; 303-444-2299; [email protected] 2 Director, Wyoming Natural Diversity Database, University of Wyoming, Dept. 3381, 1000 E. University Ave., Laramie, WY 82071, 307-766-3023; [email protected] prepared for United States Department of the Interior Bureau of Land Management Wyoming State Office Cheyenne, Wyoming September 2004 1 2 Reed-Eckert, Meaney, and Beauvais – Ursus arctos September 2004 Table of Contents INTRODUCTION ................................................................................................................................. 3 NATURAL HISTORY ........................................................................................................................... 3 Morphological Description ...................................................................................................... 3 Taxonomy and Distribution ..................................................................................................... 5 Taxonomy .......................................................................................................................................5 Distribution .....................................................................................................................................5 Habitat Requirements............................................................................................................. 8 General ............................................................................................................................................8 Active seasons...............................................................................................................................11 Denning period..............................................................................................................................12 Landscape Pattern .........................................................................................................................14 Area Requirements........................................................................................................................15 Movement and Activity Patterns ............................................................................................16 Dispersal........................................................................................................................................18 Migration.......................................................................................................................................18 Daily Activity................................................................................................................................18 Reproduction and Survivorship..............................................................................................19 Breeding Behavior.........................................................................................................................19 Breeding Phenology ......................................................................................................................19 Breeding Habitat ...........................................................................................................................20 Fecundity and Survivorship....................................................................................................21 Population Demographics......................................................................................................23 Limiting Factors............................................................................................................................23 Metapopulation Dynamics ............................................................................................................24 Genetic Concerns ..........................................................................................................................24 Food Habits...........................................................................................................................24 Food items.....................................................................................................................................24 Foraging Strategy..........................................................................................................................27 Foraging Variation ........................................................................................................................28 Community Ecology...............................................................................................................29 CONSERVATION .............................................................................................................................. 30 Conservation Status ..............................................................................................................30 USDI Fish and Wildlife Service....................................................................................................30 USDI Bureau of Land Management..............................................................................................30 USDA Forest Service....................................................................................................................31 State Wildlife Agencies.................................................................................................................31 State Natural Heritage Program ....................................................................................................31 Biological Conservation Issues..............................................................................................32 Abundance.....................................................................................................................................32 Trends............................................................................................................................................33 Abundance Trends..................................................................................................................33 Population Extent and Connectivity Trends ...........................................................................34 Habitat Trends ........................................................................................................................35 Range Context...............................................................................................................................37 Extrinsic Threats and Reasons for Decline ...................................................................................37 Anthropogenic Impacts...........................................................................................................37 Page 1 of 54 Reed-Eckert, Meaney, and Beauvais – Ursus arctos September 2004 Invasive Species......................................................................................................................38 Genetic Factors .......................................................................................................................38 Stochastic Factors and Climate Change..................................................................................39 Intrinsic Vulnerability ...................................................................................................................39 Habitat Specificity and Fidelity..............................................................................................39 Territoriality and Area Requirements.....................................................................................40 Susceptibility to Disease and Parasites...................................................................................40 Dispersal Capability................................................................................................................40 Reproductive Capacity............................................................................................................41 Sensitivity to Disturbance.......................................................................................................41 Protected Areas .............................................................................................................................42 CONSERVATION ACTION ................................................................................................................ 43 Existing or Future Conservation Plans...................................................................................43 Conservation Elements..........................................................................................................45 Inventory and Monitoring .............................................................................................................45 Habitat Preservation and Restoration............................................................................................46 Augmentation and Reintroduction ................................................................................................46 INFORMATION NEEDS ..................................................................................................................... 46 Rangewide Needs .................................................................................................................46 Wyoming Needs ....................................................................................................................47