CALIFORNIA BAT MITIGATION TECHNIQUES, SOLUTIONS, AND EFFECTIVENESS Prepared by: H. T. Harvey & Associates Dave Johnston, Ph.D. with Greg Tatarian Wildlife Research Associates Santa Rosa, CA and Elizabeth Pierson, Ph.D., Consultant Berkeley, CA Prepared for: California Department of Transportation (Caltrans) Office of Biological Studies and Technical Assistance Sacramento, California and Gene R. Trapp, Ph.D., Coordinator Professor Emeritus California State University Sacramento Foundation 6000 J Street Sacramento, California December 29, 2004 Project Number 2394-01 TABLE OF CONTENTS 1.0 INTRODUCTION.................................................................................................................................1 2.0 PROJECT GOALS ...............................................................................................................................2 3.0 CONSERVATION STATUS OF BATS.............................................................................................3 3.1 CONTEXT ........................................................................................................................................3 3.2 MITIGATION FOR BATS: AN OVERVIEW AND INTRODUCTION TO THE URL SITES TABLE AND THE ENDNOTE LIBRARY.........................................................................................3 4.0 BATS AND TRANSPORTATION RELATED STRUCTURES.....................................................6 4.1 RELEVANT BIOLOGICAL AND ECOLOGICAL FACTORS .................................................6 4.2 ROOSTING ECOLOGY..................................................................................................................6 4.2.1 An Overview..............................................................................................................................6 4.2.2 Structural Features of Roosts.....................................................................................................7 4.2.3 Why Bridges?...........................................................................................................................10 4.3 FORAGING ECOLOGY...............................................................................................................11 5.0 LEGAL STATUS AND ITS IMPLICATIONS FOR PROJECTS .................................................12 5.1 NO FEDERALLY-LISTED BAT SPECIES IN CALIFORNIA................................................12 5.2 NO STATE-LISTED BAT SPECIES IN CALIFORNIA ...........................................................12 5.3 CALIFORNIA CODE, TITLE 14, §465.5: USE OF TRAPS AND EXISTING CCR 4152, 4180........................................................................................................................................................12 5.4 CALIFORNIA ENVIRONMENTAL QUALITY ACT (CEQA)...............................................13 5.5 STREAMBED ALTERATION AGREEMENTS §1600............................................................13 5.6 PROPOSED DRAFT CALTRANS BAT POLICY.....................................................................14 6.0 ROLES AND RESPONSIBILITIES.................................................................................................15 6.1 CALTRANS....................................................................................................................................15 6.2 DEPARTMENT OF FISH AND GAME (DFG) .........................................................................16 6.3 ENVIRONMENTAL CONSULTANTS......................................................................................16 6.4 NON-GOVERNMENTAL ORGANIZATIONS.........................................................................17 7.0 PERMIT REQUIREMENTS .............................................................................................................18 8.0 PREDICTING THE IMPACTS.........................................................................................................20 8.1 INTRODUCTION ..........................................................................................................................20 8.2 TEMPORARY IMPACTS: DISTURBANCE ............................................................................20 8.3 TEMPORARY IMPACTS: SHORT-TERM LOSS OF THE USE OF A BAT ROOST ........20 8.4 PERMANENT IMPACTS: MODIFICATION OF ROOSTS....................................................20 8.5 PERMANENT IMPACTS: LOSS OF ROOSTS........................................................................21 8.6 PERMANENT IMPACTS: FRAGMENTATION AND ISOLATION ....................................21 8.7 PERMANENT IMPACTS: INCREASE IN HUMAN ACTIVITY ..........................................22 9.0 MITIGATION STRATEGIES...........................................................................................................23 9.1 ON-SITE NIGHT ROOST AVOIDANCE, MINIMIZATION, MITIGATION MEASURES 25 9.1.1 Avoidance (No Impact) ...........................................................................................................25 9.1.2 Minimization (Minor Impact) .................................................................................................25 9.1.3 Minimization (Moderate Impact)............................................................................................26 9.1.4 Mitigation (Major Impact).......................................................................................................26 9.2 ON-SITE DAY ROOST AVOIDANCE, MINIMIZATION, MITIGATION ...........................26 9.2.1 Avoidance (No Impact) ...........................................................................................................27 California Bat Mitigation H. T. Harvey & Associates i Techniques, Solutions, and Effectiveness December 29, 2004 9.2.2 Minimization (Minor Impact) .................................................................................................27 9.2.3 Minimization (Moderate Impact)............................................................................................27 9.2.4 Mitigation (Major Impact).......................................................................................................27 9.3 WINTERING AND HIBERNATION ROOSTS .........................................................................30 9.3.1 Avoidance (No Impact) ...........................................................................................................30 9.3.2 Minimization (Minor Impact) .................................................................................................30 9.3.3 Minimization (Moderate Impact)............................................................................................31 9.3.4 Mitigation (Major Impact).......................................................................................................31 10.0 MITIGATION RESULTS FOR RECENT PROJECTS IN CALIFORNIA ................................32 10.1 OVERVIEW .................................................................................................................................32 10.2 BAT MITIGATION STRUCTURES .........................................................................................32 10.2.1 Original Habitat Retained......................................................................................................32 10.2.2 Original Habitat Lost; New On-Site Habitat Provided........................................................35 10.2.3 Original Habitat Lost; New Off-Site Habitat Provided .......................................................36 10.3 CONCLUSIONS AND RECOMMENDATIONS ....................................................................37 10.3.1 Problems with Bat Mitigation Projects.................................................................................37 10.3.2 Recommendations .................................................................................................................38 11.0 LITERATURE CITED.....................................................................................................................39 11.1 GENERAL REFERENCES.........................................................................................................39 11.2 PAPERS ON DISTRIBUTION OF BATS IN CALFORNIA ..................................................39 11.3 REFERENCES ON BATS AND BRIDGES .............................................................................41 11.4 PERSONS CONTACTED...........................................................................................................42 FIGURES: Figure 9-1. Add-on Panels (Brian Keeley)..............................................................................................29 TABLES: Table 4-1. Roosting Patterns for California Bat Species. .........................................................................8 Table 10-1. Bat Mitigation Results..........................................................................................................33 APPENDICES: Appendix A. Case Study 1 San Joaquin River Bridge, #42C0003 (Auberry Road Bridge) ................43 Appendix B. Case Study 2 U.S. Interstate 880/Alameda Creek Bridge #33-0240 ...............................48 Appendix C. Case Study 3 Salinas River Bridge #44C0051 (Monterey Bridge No. 450 – Bradley Road Bridge) .....................................................................................................................................55 Appendix D. Case Study 4 Hacienda Bridge #33-0180 .........................................................................63