BATS OF SOUTHERN WYOMING: DISTRIBUTION & MIGRATION YEAR 1 REPORT 2012 Prepared by: Hannah Griscom, Zoologist Mark Andersen, GIS Specialist Douglas Keinath, Lead Zoologist Wyoming Natural Diversity Database University of Wyoming 1000 E. University Ave., Department 3381 Laramie, Wyoming 82071 Prepared for: Bureau of Land Management 5353 Yellowstone Cheyenne, WY 82009 Suggested Citation: Griscom, H.R., M.D. Andersen, and D.A. Keinath. 2012. Bats of southern Wyoming: distribution and migration, year 1 report. Prepared for the USDI Bureau of Land Management by the Wyoming Natural Diversity Database, University of Wyoming, Laramie, Wyoming. Bats of Southern Wyoming, Wyoming Natural Diversity Database, 2012 2 Bats of Southern Wyoming, Wyoming Natural Diversity Database, 2012 TABLE OF CONTENTS EXECUTIVE SUMMARY ....................................................................................................................................... 5 INTRODUCTION .................................................................................................................................................... 6 Study Objectives ................................................................................................................................................... 9 METHODS ............................................................................................................................................................... 9 Field Surveys ........................................................................................................................................................ 9 Mist Net Surveys............................................................................................................................................................. 10 Acoustic Surveys ............................................................................................................................................................ 11 Habitat Analyses ................................................................................................................................................ 12 Habitat as a predictor of bat richness and activity ........................................................................................................... 12 Habitat as a predictor of species presence ....................................................................................................................... 13 Distribution and Migration Models ................................................................................................................... 14 Summer Distribution Models .......................................................................................................................................... 14 Migration Stopover Models ............................................................................................................................................ 16 Bat Exposure to Wind Energy Development ................................................................................................................... 20 RESULTS ............................................................................................................................................................... 21 Mist Net and Acoustic Surveys ........................................................................................................................... 21 Habitat Analyses ................................................................................................................................................ 22 Bat Richness and Activity ............................................................................................................................................... 22 Species Presence ............................................................................................................................................................. 23 Distribution, Migration & Exposure Models ..................................................................................................... 23 DISCUSSION ......................................................................................................................................................... 24 Distribution and Habitat .................................................................................................................................... 24 Management Implications and Important Bat Habitat ...................................................................................... 26 ACKNOWLEDGEMENTS .................................................................................................................................... 28 LITERATURE CITED ........................................................................................................................................... 29 TABLES ................................................................................................................................................................. 32 FIGURES ................................................................................................................................................................ 38 APPENDICES ........................................................................................................................................................ 44 APPENDIX A: SPECIES ACCOUNTS .............................................................................................................. 45 Little Brown Myotis (Myotis lucifugus) .......................................................................................................................... 46 Western Small-footed Myotis (Myotis ciliolabrum) ....................................................................................................... 47 Hoary Bat (Lasiurus cinereus) ........................................................................................................................................ 48 Long-legged Myotis (Myotis volans) .............................................................................................................................. 49 Silver-haired Bat (Lasionycteris noctivagans) ................................................................................................................ 50 Western Long-eared Myotis (Myotis evotis) ................................................................................................................... 51 Big Brown Bat (Eptesicus fuscus) ................................................................................................................................... 52 Fringed Myotis (Myotis thysanodes) ............................................................................................................................... 53 Pallid Bat (Antrozous pallidus) ....................................................................................................................................... 54 3 Bats of Southern Wyoming, Wyoming Natural Diversity Database, 2012 Townsend’s Big-eared Bat (Corynorhinus townsendii) .................................................................................................. 55 Eastern Red Bat (Lasiurus borealis) ............................................................................................................................... 56 APPENDIX B: LITERATURE REVIEW OF BAT MIGRATION & WIND TURBINE FATALITIES ................. 57 APPENDIX C: 2011 MIST NET CAPTURE RESULTS ..................................................................................... 66 APPENDIX D: 2011 SPECIES OCCURRENCES ............................................................................................. 68 APPENDIX E: WYOMING BAT SPECIES IDENTIFICATION KEY ................................................................ 76 APPENDIX F: WYOMING ANABAT CALL KEY .............................................................................................. 81 APPENDIX G: 2011 BLANK DATASHEETS .................................................................................................... 86 4 Bats of Southern Wyoming, Wyoming Natural Diversity Database, 2012 EXECUTIVE SUMMARY We conducted bat surveys throughout southern Wyoming to gain a better understanding of species composition, distribution, habitat, and migration. The impetus for this work is the ongoing expansion of wind energy development and its potential impact on resident and migratory bats. Previous studies have suggested that the location of wind turbines in relation to bat habitat and movement could significantly mitigate the number of bats killed annually. Our aim is to better understand bat distribution and migration in order to map it in relation to areas of high wind energy potential. The result is a tool for managers and planners to use in mitigating the potential impacts of proposed wind energy facilities on bats. Our work is also intended to provide a baseline of bat health in the face of White-nose Syndrome, a disease that has devastated bat populations elsewhere, and is predicted to spread to Wyoming in the near future. We completed 17 mist net and 76 acoustic surveys in 2011 which resulted in 333 occurrences of 11 bat species. Several species typically associated with forests were commonly found in sagebrush steppe and one species was found far south of its purported range. All three of Wyoming’s migratory bat species (hoary, silver-haired, and eastern red bat) were found in the study area, and the hoary and silver-haired