NCHRP 25-25 Task 102 Manual
Total Page:16
File Type:pdf, Size:1020Kb
Bridging the Gap Between Bats & Transportation Projects A Manual of Best Management Practices for Bridges, Artificial Roosts, & Other Mitigation Approaches for North American Bats Prepared for AASHTO Committee on Environment and Sustainability Prepared by Dale W. Sparks, David Tull Robin Perez Ted Cable, Robert Tunison Edward Samanns Environmental Solutions & Innovations, Inc. Louis Berger US, Inc. Cincinnati, Ohio Morristown, New Jersey The information contained in this report was prepared as part of NCHRP Project 25-25, Task 102, National Cooperative Highway Research Program. SPECIAL NOTE: This report IS NOT an official publication of the National Cooperative Highway Research Program, Transportation Research Board, National Research Council, or The National Academies. Contractor’s Final Report June 2019 ACKNOWLEDGEMENTS This study was conducted for the AASHTO Committee on Environment and Sustainability, with funding provided through the National Cooperative Highway Research Program (NCHRP) Project 25-25, Task 102, Artificial Bat Roost Mitigation Designs and Standardized Monitoring Criteria. The NCHRP is supported by annual voluntary contributions from the state Departments of Transportation. Project 25- 25 is intended to fund quick response stud-ies on behalf of the Committee on Environment and Sustainability. The report was prepared by Dale W. Sparks, David Tull, Ted Cable, and Robert Tunison of Environmental Solutions & Innovations, Inc; and Robin Perez and Edward Samanns of Louis Berger US, Inc. The work was guided by a technical working group that included: • Timothy Hill, Ohio Department of Transportation • Amy Bailey, California Department of Transportation • Kris J. Gade, Arizona Department of Transportation • Christine (Chris) Maguire, Oregon Department of Transportation • Jeff S. Peterson Colorado Department of Transportation • Mary Kay Solberg, Iowa Department of Transportation • Kevin Moody, FHWA (Liaison) The project was managed by Ann Hartell NCHRP Senior Program Officer. DISCLAIMER The opinions and conclusions expressed or implied are those of the research agency that performed the research and are not necessarily those of the Transportation Research Board or its sponsoring agencies. This report has not been reviewed or accepted by the Transportation Research Board Executive Committee or the Governing Board of the National Research Council. ii BRIDGING THE GAP BETWEEN BATS AND TRANSPORTATION PROJECTS: A MANUAL OF BEST MANAGEMENT PRACTICES FOR BRIDGES, ARTIFICIAL ROOSTS, AND OTHER MITIGATION APPROACHES FOR NORTH AMERICAN BATS Dale W. Sparks, David Tull, Ted Cable, and Robert Tunison Environmental Solutions & Innovations, Inc. 4525 Este Avenue Cincinnati, OH 45232 AND Robin Perez and Edward Samanns Louis Berger US, Inc. 412 Mt. Kemble Avenue, Morristown, NJ 07962 iii TABLE OF CONTENTS Page 1.0 INTRODUCTION .................................................................................................................... 1 2.0 DEFINITIONS/GLOSSARY .................................................................................................... 2 3.0 INTRODUCTION TO NORTH AMERICAN BATS .................................................................. 4 3.1 Diversity .............................................................................................................................. 4 3.2 Conservation Status ............................................................................................................ 4 3.3 What Bats Eat ..................................................................................................................... 5 3.4 Financial Impact of Bats ...................................................................................................... 5 3.5 Seasonal Ecology ............................................................................................................... 6 4.0 RECOGNIZING BAT HABITAT ............................................................................................. 7 4.1 Caves, Mines, and Other Underground Habitats................................................................. 7 4.2 Forested Habitat.................................................................................................................. 8 4.3 Buildings ............................................................................................................................. 8 4.4 Rocky Habitat ...................................................................................................................... 8 4.5 Bridges, Culverts, and Transportation Infrastructure ........................................................... 8 4.6 Landscape Considerations ................................................................................................ 10 4.7 Survey Techniques ........................................................................................................... 10 4.7.1 Mist Nets ...................................................................................................................... 10 4.7.2 Harp Traps ................................................................................................................... 10 4.7.3 Acoustic Bat Detectors ................................................................................................. 10 4.7.4 Examining Potential Roosts ......................................................................................... 11 4.7.5 Emergence Counts ...................................................................................................... 11 5.0 AVOIDING AND MINIMIZING IMPACTS ............................................................................. 12 6.0 MITIGATION TYPES FOR UNAVOIDABLE IMPACTS ....................................................... 13 6.1 Ways to Enhance Habitat .................................................................................................. 14 6.1.1 Stand-Alone Artificial Roosts ........................................................................................ 14 6.1.2 Bat-Friendly Bridges..................................................................................................... 16 6.2 Location of Mitigation (Relative to Impacts) ...................................................................... 20 6.3 Common Financial Approaches to Mitigation .................................................................... 20 7.0 LITERATURE CITED ........................................................................................................... 21 8.0 ADDITIONAL READING AND RESOURCES ...................................................................... 21 8.1 Papers About Mitigation .................................................................................................... 21 8.2 Papers About Artificial Roosts ........................................................................................... 21 8.3 Papers About Bats and Bridges ........................................................................................ 22 iv 1.0 INTRODUCTION There is an increase in awareness about interactions between bats and transportation infrastructure. Bats, including several federal threatened and endangered species, occupy bridges throughout the contiguous 48 states. Bridges provide critical habitat and function as sites for maternity colonies, day roosts, and night roosts. This manual provides an overview of bat ecology to inform land managers, transportation biologists, and natural resource and wildlife agencies about general bat ecology and Best Management Practices (BMPs) for addressing potential conflicts between bats and transportation structures. BMPs are divided into three categories: 1) Inspection ‒ recognizing habitat used or potentially used by bats, 2) Avoidance and Minimization ‒ taking steps (i.e., avoidance and minimization measures) to reduce or eliminate negative impacts to bats, and 3) Mitigation ‒ identifying options to off-set or mitigate negative effects of highway projects. The National Cooperative Highway Research Program Project 25-25 Task 102 supported the research effort needed to create this BMP manual and a more technical companion document that includes pertinent statistical analyses and references. Most of this material is summarized herein with the goal of producing a concise and useful product for the end user. The BMP manual is targeted toward professionals who regularly address interactions between transportation projects and environmental laws. Interviews conducted as part of the research effort revealed contrasting viewpoints between the professionals employed by transportation agencies (such as Departments of Transportation, DOTs) and those employed by resource-centric organizations including the U.S. Fish and Wildlife Service (USFWS), State Departments of Natural Resources (DNRs), and academics. Such divergent viewpoints arise from different goals (i.e., building projects as opposed to species recovery efforts) and from dissimilar areas of expertise. Expecting a transportation engineer to understand the details of bat biology is not reasonable and expecting bat biologists to understand the nuanced differences among different types of bridges and culverts is equally unreasonable. Different perspectives naturally result from different objectives and can unnecessarily complicate communication. This manual contains sections dedicated to defining terminology to simplify communication, introducing the ecology of bats in the U.S., and describing methods to recognize