Many bat species use bridges, culverts, and other transportation structures for daytime and/or night-time roosting habitat and for seasonal hibernacula and maternity sites. These structures provide valuable habitat for bats whose populations have been declining in many regions as a result of loss of natural habitat and infection by the fungal disease known as white-nose syndrome. In 2015, the U.S. Fish and Wildlife Service listed the northern long-eared bat (Myotis septentrionalis) as threatened under the federal Endangered Species Act; additional bat species may warrant listing in the coming years. Many states also have legal protections for bat species.
When state departments of transportation (DOTs) need to repair or replace transportation structures, they must take measures to avoid and minimize impacts to bats if protected species are present. Such measures are particularly important during the maternity season to avoid further losses to bat populations. To meet all of these objectives, state DOTs can restrict construction or maintenance activities to periods when bats are not present. However, temporal avoidance is challenging in regions where winter conditions and cold temperatures limit the construction season.
Alternatives to temporal avoidance include methods that temporarily deter or exclude bats from a structure for the shortest length of time needed for construction or maintenance activities, with the intent to allow bats to return once the project is complete. Methods to accomplish this include physically blocking bats from the structure or cavities with exclusion or filler material; modifying roosting habitat by changing microclimatic conditions (e.g., installing fans or removing expansion joint glands); and deterring bats with lights or noise. One promising method is the use of non-lethal ultrasonic acoustic devices.
However, effectively excluding or deterring bats can be challenging. Some deterrence methods require costly equipment or materials and considerable labor for installation and maintenance. Some project locations may not have a readily available power source to operate deterrence equipment. At some sites, expensive or sensitive deterrence equipment can be vulnerable to vandalism and/or theft. Further, if a method is not effective and bats continue to use the bridge, the project may be delayed. Additionally, if the intent is to allow bats to return to the structure after the project is completed, the deterrence should be temporary in its effect. Selecting a method that will be effective in deterring or excluding bats and be feasible for the project requires consideration of bat behavior and biological needs, project characteristics, and site conditions.
Methods that are appropriate for the project and target species, properly timed, and effective at temporarily deterring and/or excluding bats from a transportation structure provide several benefits. In addition to reducing impacts on imperiled bat species and successfully meeting regulatory requirements, improved environmental stewardship can strengthen interagency collaboration and partnerships. Effective methods can make construction schedules and costs more predictable, thereby increasing overall cost-effectiveness and reliability in delivering transportation projects and programs for the traveling public.
Previous research has investigated a number of bat deterrence and exclusion methods, although in practice, outcomes have been somewhat mixed and documented examples are limited. Research is needed to evaluate current and promising methods for temporarily deterring and/or excluding bats from a range of structure types and to provide guidelines for state DOTs on selecting and implementing appropriate and effective methods.
The objective of the research is to develop a handbook for state DOT environmental staff and design and maintenance engineers on how to select and implement methods to temporarily deter and/or exclude bats from transportation structures ahead of and during construction and maintenance activities. The handbook will describe methods that are (1) sensitive to the biological needs of bats and (2) effective for a range of geographical locations, project types, and site conditions. The research will include field evaluations of a variety of methods, with a focus on non-lethal ultrasonic acoustic devices used alone and in combination with other methods.
The NCHRP is seeking the insights of proposers on how best to achieve the research objective. Proposers are expected to describe research plans that can realistically be accomplished within the constraints of available funds and contract time. Proposals must present the proposers' current thinking in sufficient detail to demonstrate their understanding of the issues and the soundness of their approach to meeting the research objective.
The proposed research plan will be divided into phases and each phase divided into tasks. The research plan should build in appropriate checkpoints with the NCHRP project panel, including a web-enabled kick-off meeting, an in-person interim report review meeting, and additional web-enabled meetings tied to panel review and/or NCHRP approval of key deliverables as appropriate.
Anticipated activities and deliverables in Phase I include but are not limited to:
- Conducting a rapid review of currently used and promising methods to temporarily deter and/or exclude bats from transportation structures. Information for the review may be collected from surveys, interviews, project and/or permitting documents, research literature, and other sources. The review should also identify any promising methods that may be considered for evaluation in combination with ultrasound acoustics in Phase II;
- Documenting and synthesizing the results of the review; and
- Developing a proposed plan for field tests that describes:
- Study design and schedule;
- Proposed field sites;
- Method or combination of methods to be evaluated;
- Target bat species and any non-target species that may be affected;
- Permitting requirements and how permits will be secured;
- Monitoring strategy to evaluate effectiveness in deterring and/or excluding bats and the subsequent return of bats; and
- Proposed site survey and reconnaissance of field test sites.
Note: Proposers should describe their approach to collecting information, including anticipated challenges (e.g., low survey response rates) and how these challenges will be overcome. A detailed plan for collecting information on current and promising methods, including data collection instruments, target respondents, literature search strategies, and other relevant information will be included in the Amplified Work Plan.
Phase I will culminate with a report documenting the activities and findings of Phase I along with a proposed plan for Phase II. Following a one-month review by NCHRP, the research entity will present the report at a web-enabled meeting with the NCHRP panel, hosted by NCHRP. Phase I is limited to no more than 6 months with a budget of up to $75,000.
No work shall be initiated on Phase II activities prior to NCHRP review and approval of the plan for Phase II.
Phase II will focus on conducting field tests of ultrasound acoustic deterrence methods, used alone and in combination with other methods, and the analysis of the results. The field tests will be conducted at multiple sites with sufficient variation in roost and structure types and characteristics, and bat genera/species to be generalizable to those commonly encountered by state DOTs. Accomplishing this will require conducting multiple field tests using a robust research design.
Note: Proposers should describe their conceptual research design for the field tests, including number of tests, geographic locations, structure types and characteristics, roost types and characteristics, anticipated bat genera/species, and proposed methods.
Anticipated activities and deliverables in Phase II include but are not limited to:
- A site survey and reconnaissance of proposed field test sites;
- A technical memorandum that draws from the site survey and reconnaissance to develop complete details on the proposed field test sites and field test plan;
- Regular updates on field test activities and results; and
- A report presenting the complete results and analysis of the field tests.
Note: Following a one-month review by NCHRP, the research entity will present the technical memorandum at a one-day, in-person interim meeting to be held in Washington, D.C. NCHRP will provide a meeting facility and pay travel costs for panel members to attend the interim meeting. No field test activity will be conducted prior to NCHRP review and approval.
Phase II will culminate with a report presenting the complete results and analysis of the field tests.
Phase III will focus on developing the final deliverables. Anticipated deliverables include but are not limited to:
- Handbook on how to select and implement methods to deter and/or exclude bats from bridges and similar structures. Topics will include but not be limited to:
- Considerations for selecting an appropriate method:
- Bat behavior and biological needs:
- Roost type (daytime, nighttime, maternity, hibernation);
- Seasonal behavior, especially the timing of the onset of the maternity season;
- Roost location on the structure (joint, crevice, open space, cavity, surface on underside of bridge, etc.);
- Anticipated post-project conditions (e.g., changes to or removal of roosting surfaces or locations); and
- Differences among bat genera and species.
- Site characteristics:
- Presence and type of nearby bodies of water;
- Proximity to wooded areas or other alternative roosting sites;
- Nearby human activity (railroads, highways, pedestrian access, etc.); and
- Weather and seasonal conditions.
- Transportation structure type (single- or multi-span bridge, single- or multiple-deck bridge, culvert);
- Project characteristics:
- Project timeline/length of time bats need to be deterred or excluded;
- Project type (rehabilitation, partial or complete replacement, widening);
- Location on the structure of planned work (piers, deck, superstructure); and
- Feasibility of phasing work and/or deterring bats to portions of the structure that are away from active work areas (partial deterrence).
- Methods identified during the Phase I review and the Phase II field tests. For each method, describe:
- Effectiveness in deterring or excluding bats;
- Compatibility with or increased efficacy when used in combination with other methods;
- Physical extent of the effective range of deterrence;
- Effects on non-target species;
- Potential conditions that may counter-indicate a method or reduce its effectiveness;
- Key resources from research and practice that document the use and effectiveness of the method; and
- Implementation considerations, including but not limited to:
- Timing and scheduling;
- Site requirements such as power supply;
- Materials required, sample plan sheets, design details, and construction specifications;
- Relative cost;
- Staff resources needed to install, monitor, and remove equipment;
- Permitting and regulatory considerations (state and federal); and
- Logical implementer (state DOT environmental staff, construction project staff, etc.).
- Decision support matrix or similar graphic presentation of key considerations for selecting and implementing an effective method or combination of methods.
Note: The decision support matrix or similar graphic presentation will be in a downloadable digital format using software that is readily available to state DOT staff such as Microsoft Excel or Word. The development of a website or web-based tool or software is not requested.
- Stand-alone briefing document for decision-makers.
- Technical report documenting the project activities.
- Presentation slides with speaker notes in PowerPoint format summarizing the project.
- Stand-alone technical memorandum that identifies implementation pathways, key implementers of the results, and well-defined scopes of work for pilot implementations of the handbook and related materials. Potential implementation activities include pilot projects, training materials for staff at state DOTs on how to implement effective methods, or presentations to relevant practitioner audiences. The technical memorandum should provide adequate detail on timelines, budgets, and staff resources needed for specific activities to implement the results of NCHRP Project 25-63 (see Special Note D).
Note: Conducting implementation activities is not anticipated as part of NCHRP Project 25-63.
Following receipt of the draft final deliverables, the remaining 3 months shall be for NCHRP review and comment and for research agency preparation of the final deliverables.
A. The contractor is responsible for securing any and all permits that may be required to conduct the field tests. The project schedule should reflect time required to revise and/or obtain permits from the relevant regulatory agencies.
C. Proposals should include a task-by-task breakdown of labor hours for each staff member as shown in Figure 4 in the brochure, "Information and Instructions for Preparing Proposals" (https://onlinepubs.trb.org/onlinepubs/crp/docs/ProposalPrep.pdf). Proposals also should include a breakdown of all costs (e.g., wages, indirect costs, travel, materials, and total) for each task using Figures 5 and 6 in the brochure. Please note that TRB Cooperative Research Program subawards (selected proposers are considered subawards to the National Academy of Sciences, the parent organization of TRB) must comply with 2 CFR 200 – Uniform Administrative Requirements, Cost Principles, and Audit Requirements for Federal Awards. These requirements include a provision that proposers without a "federally" Negotiated Indirect Costs Rate Agreement (NICRA) shall be subject to a maximum allowable indirect rate of 10% of Modified Total Direct Costs. Modified Total Direct Costs include all salaries and wages, applicable fringe benefits, materials and supplies, services, travel, and up to the first $25,000 of each lower-tier subaward and subcontract. Modified Total Direct Costs exclude equipment, capital expenditures, charges for patient care, rental costs, tuition remission, scholarships and fellowships, participant support costs and the portion of each lower-tier subaward and subcontract in excess of $25,000.
D. The NCHRP is a practical, applied research program that produces implementable products addressing problems faced by transportation practitioners and managers. The benefits of NCHRP research are realized only when the results are implemented in state DOTs and other agencies. Implementation of the research product must be considered throughout the process, from problem statement development to research contract and beyond completion of the research. Item 4(c), "Anticipated Research Results," must include the following: (a) the "product" expected from the research, (b) the audience or "market" for this product, (c) a realistic assessment of impediments to successful implementation, and (d) the institutions and individuals who might take leadership in deploying the research product. The project panel will develop and maintain an implementation plan throughout the life of the project. The research team will be expected to provide input to an implementation team consisting of panel members, AASHTO committee members, the NCHRP Implementation Coordinator, and others in order to meet the goals of NCHRP Active Implementation: Moving Research into Practice, available at https://onlinepubs.trb.org/onlinepubs/nchrp/docs/NCHRP_ActiveImplementation.pdf.
E. Proposals are evaluated by the NCHRP staff and project panels consisting of individuals collectively very knowledgeable in the problem area. Selection of an agency is made by the project panel considering the following factors: (1) the proposer's demonstrated understanding of the problem; (2) the merit of the proposed research approach and experiment design; (3) the experience, qualifications, and objectivity of the research team in the same or closely related problem area; (4) the plan for ensuring application of results; (5) how the proposer approaches inclusion and diversity in the composition of their team and research approach, including participation by certified Disadvantaged Business Enterprises; and, if relevant, (6) the adequacy of the facilities.
Note: The proposer's approach to inclusion and diversity as well as participation by Disadvantaged Business Enterprises should be incorporated in Item 11 of the proposal.
F. Copyrights - All data, written materials, computer software, graphic and photographic images, and other information prepared under the contract and the copyrights therein shall be owned by the National Academies of Sciences, Engineering, and Medicine. The contractor and subcontractors will be able to publish this material for non-commercial purposes, for internal use, or to further academic research or studies with permission from TRB Cooperative Research Programs. The contractor and subcontractors will not be allowed to sell the project material without prior approval by the National Academies of Sciences, Engineering, and Medicine. By signing a contract with the National Academy of Sciences, contractors accept legal responsibility for any copyright infringement that may exist in work done for TRB. Contractors are therefore responsible for obtaining all necessary permissions for use of copyrighted material in TRB's Cooperative Research Programs publications. For guidance on TRB's policies on using copyrighted material please consult Section 5.4, "Use of Copyrighted Material," in the Procedural Manual for Contractors.