Wildlife Crossings Guidance Manual California Department of Transportation Prepared by: Robert J. Meese, Fraser M. Shilling, and James F. Quinn, Information Center for the Environment, Department of Environmental Science and Policy, University of California, One Shields Avenue, Davis, CA 95616. Under contract to the California Department of Transportation, Environmental Division, supervised by Amy Pettler. Version 1.0 October, 2007 Acknowledgments: We appreciate the thoughtful reviews and suggestions of many Caltrans staff, especially Susan Leroy (District 1), Kally McCormick (District 7), Dave Hacker (District 5), Dan Whitley (District 2), Arianne Preite (District 12), Margaret Gabil (District 4), Margaret Lawrence (District 10-L), Robert James (District 11), Maureen Doyle (District 7), and Zack Parker (District 6), Rebecca Loeffler (HDR, Inc.), Elizabeth Chattin of the Ventura County Planning Department, U.S. Fish & Wildlife Service biologists Susan Jones, Jonathan Snyder, Ray Bosch, Karen Leyse, and Rocky Montgomery, Larry Vinzant, F.H.W.A., and Joe Vincenty, California Department of Fish & Game. Cover photo: William Boarman, U.S.G.S. ii Table of Contents List of Figures................................................................................................................................vi Index of Tables..............................................................................................................................vii Preface......................................................................................................................................... viii Manual Goals..........................................................................................................................viii Manual Map............................................................................................................................viii Executive Summary........................................................................................................................x What are Wildlife Crossings & Why Do They Matter?............................................................. x Regulatory Considerations.................................................................................................... x Wildlife Habitat and Connectivity........................................................................................xi Field Surveys Confirm Presence of Wildlife........................................................................xi Project Managers, Engineers, & Planners...........................................................................xii Traffic.................................................................................................................................. xii Reducing Highway Effects on Wildlife Crossing.................................................................... xii Project Modification............................................................................................................xii Modifying Driver Behavior.................................................................................................xii Structures............................................................................................................................xiii Maintenance............................................................................................................................xiii Post-project Assessments/Adaptive Management.................................................................. xiii 1 What You Need to Know.............................................................................................................. 1 1.1. Introduction.......................................................................................................................... 1 1.1.1 Why Use This Manual..................................................................................................2 1.1.2 Who Should Use this Manual.......................................................................................2 1.1.3 How to Use This Manual..............................................................................................3 1.2. Federal and State Wildlife Protection Laws.........................................................................7 1.3. Wildlife: Functional, Taxonomic, and Special Status Groups...........................................12 1.3.1 Wildlife: Functional Groups......................................................................................12 1.3.2 Wildlife: Taxonomic Groups..................................................................................... 13 1.3.3 Wildlife: Special Status Species................................................................................ 13 1.4. Special Habitats..................................................................................................................14 1.5. Sources of Species-Level Information............................................................................... 15 1.5.1 Internet Resources...................................................................................................... 15 1.5.2 Books..........................................................................................................................16 1.6. Identifying Wildlife Crossings........................................................................................... 17 1.6.1 Case Studies: Existing Efforts to Enhance Wildlife Crossing....................................18 Existing Efforts in California..........................................................................................18 Examples of Wildlife Crossing Projects Outside California.......................................... 19 2 Baseline Assessment................................................................................................................... 20 2.1. Basic Steps to Establish Your Baseline.............................................................................. 20 2.1.1 Understanding Landscape-level Connectivity: Bioregional Perspective...................21 2.1.2 Understanding Project-level Crossing Issues............................................................. 23 2.2. Developing Your Baseline for Wildlife Movement............................................................24 2.2.1 Identify, Acquire, and Review Data Sources..............................................................24 2.2.2 Identify the Need for Additional Field Surveys and Assessments.............................25 Establish Intended Outcome or Application of Survey Data..........................................25 iii Survey Site Selection......................................................................................................28 Survey Sample Size........................................................................................................ 29 2.2.3 Survey and Detection Methods.................................................................................. 30 Visual (= Field) Observations.........................................................................................33 Track-count Surveys....................................................................................................... 33 Track Plates.....................................................................................................................33 Raked Soil.......................................................................................................................34 Live Traps....................................................................................................................... 35 Pitfall Traps.....................................................................................................................35 Hair Traps....................................................................................................................... 36 Remotely-triggered Cameras.......................................................................................... 36 GPS and Radio Collars................................................................................................... 37 2.2.4 Required Expertise..................................................................................................... 37 2.2.5 Data Considerations....................................................................................................38 Minimum Observation Data Set..................................................................................... 38 2.3 Collaborative Approach..................................................................................................... 39 2.4 Use of GIS and Models to Predict Wildlife Passage..........................................................39 2.4.1 Large-scale Prioritization of Wildlife Crossing Corridors......................................... 40 2.5 Analyze and Interpret Data to Evaluate Crossing Potential............................................... 43 2.5.1 Areas of High Connectedness.....................................................................................43 2.5.2 Adjacent important conservation areas.......................................................................43 2.5.3 Separation of seasonally-used habitats.......................................................................43 2.6 Existing Connectivity Attributes/Infrastructure................................................................. 44 2.7 Road-side Vegetation..........................................................................................................45