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Wildlife & Ecosystems


This section provides an overview of information regarding transportation agency programs related to protection and mitigation of impacts to ecosystems and wildlife. Topics include:



Transportation program and project delivery in a manner that is sensitive to wildlife and habitat is an ongoing concern and can present challenges for transportation agencies. Transportation agencies are required to evaluate project impacts to endangered and threatened animal and plant species and to consider resource conservation plans and inventories as part of the transportation planning process.

While progress has been made in developing methods to address project-specific impacts, a broader ecosystem approach to transportation project planning and development offers promise for even greater benefits to wildlife and habitat while at the same time ensuring mobility for the human population.

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Endangered Species Act

The primary federal law dealing with wildlife protection in the United States is the federal Endangered Species Act (ESA). The ESA outlines procedures for federal agencies to follow when taking actions that may impact listed species, and contains exceptions and exemptions.

The ESA is administered by the U.S. Fish and Wildlife Service (FWS) and National Oceanic and Atmospheric Administration’s Marine Fisheries Service (the Services). The act and its implementing regulations provide broad protection for those species of insects, birds, fish, mammals, reptiles, crustaceans, grasses, flowers and trees that are identified as threatened or endangered in the United States or elsewhere.  Provisions in the act and regulations are intended for listing species and critical habitat, as well as for species recovery plans. The FWS maintains the list of endangered species and threatened species.

ESA Section 7 directs all Federal agencies to use their existing authorities to conserve threatened and endangered species and, in consultation with the FWS, to ensure that their actions do not jeopardize listed species or destroy or adversely modify critical habitat. Section 7 applies to Federal actions that may affect listed species, such as Federal approval of transportation projects.

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Section 7 Consultation

The process for managing Section 7 consultations for transportation projects is described in FHWA Guidance Memo on Management of the Endangered Species Act Consultation Process.

According to FHWA guidance, the National Environmental Policy Act (NEPA) review process for transportation “drives the evaluation of biological resources in the project area concurrent and interdependent with the ESA Section 7 consultation process.”

“NEPA requires evaluation of impacts to federally listed endangered species, dependent on the scope of the project, ecological importance and distribution of the affected species, and intensity of potential impacts of the project,” the guidance states.

Section 7 requires, at a minimum, a request to the Services for information on listed or proposed species or critical habitat in the project vicinity. If no species or habitats of concern are found, the environmental analysis is complete, and FHWA concurs in writing with a no effect determination by the transportation agency. NEPA documentation should include the determination of no effect.

If the Services indicate that project area includes areas known to be inhabited or potentially inhabited by one or more listed species, or if the area includes designated critical habitat, then the transportation agency has the option of entering informal consultation or requesting formal consultation with the Services. 

The endangered species analysis should be appropriate to the scope of the project.  It may be prepared as a biological evaluation (BE), which is developed during informal consultation and may be used to initiate formal consultation for environmental assessments and categorical exclusions, or as a biological assessment (BA) for projects that require environmental impact statements.

Following consultation, the Service then issues a biological opinion, including an analysis of whether the proposed action would be likely to jeopardize the continued existence of the species or adversely modify designated critical habitat. If a jeopardy or adverse modification determination is made, the biological opinion identifies reasonable and prudent alternatives that could allow the project to move forward.

If the Service issues either a non-jeopardy opinion or a jeopardy opinion that contains reasonable and prudent alternatives, it may include an incidental take statement. “Incidental take” is defined as take that is incidental to, and not the purpose of, an otherwise lawful activity. The statement includes terms and conditions designed to reduce the impact to the species.

For projects that fall under a programmatic determination for particular classes of actions considered “not likely to adversely affect” listed or proposed species or critical habitat, no further evaluation is required. These may include actions such as signing, striping, overlays, minor reconstruction, and similar activities with insignificant impacts to species. For these types of actions, FWS and the Federal Highway Administration have provided joint guidance to streamline ESA compliance in Department of Transportation Programmatic Consultation Guidance.

In addition, a joint agency agreement between FHWA and FWS, issued in February 2005, focuses specifically on the timing and information requirements under ESA Section 7(a)(2). For more information, link to Joint Agency Agreement on ESA’s Formal Consultation Process.

For additional information on the Section 7 consultation process, see the FHWA Guidance Memo on Management of the Endangered Species Act Consultation Process, the FWS Consultations with Federal Agencies fact sheet or the FWS Consultation Handbook.

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Migratory Bird Treaty Act

The Migratory Bird Treaty Act (16 USC 760e-760g [2003]) protects most common migratory wild birds in the United States from being killed, captured, collected, possessed, bought, sold, traded, shipped, imported, or exported. The law protects migratory birds as well as “any part, nest, or egg of any such bird."

Permits are required for Federal-aid highway projects that are likely to result in the taking of birds protected under the act. FWS issues such permits pursuant to the regulations at 50 CFR Part 13 and Part 21.

Birds that are protected by the act include common songbirds, waterfowl, shorebirds, hawks, owls, eagles, ravens, crows, native doves and pigeons, swifts, martins, swallows, and others. For a complete list of protected birds, link to Birds Protected by the Migratory Bird Treaty Act. For more information on the act, link to the FWS digest of the Migratory Bird Treaty Act.

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Fish and Wildlife Coordination Act

The Fish and Wildlife Coordination Act (16 U.S.C. 661-667e) calls for conservation of wildlife resources related to projects where the "waters of any stream or other body of water” are impounded, diverted or modified by any agency under a Federal permit or license.

The law requires consultation with FWS and state fish and wildlife agencies for the purpose of "preventing loss of and damage to wildlife resources." FWS and the state fish and wildlife agencies are responsible for administering the act.

For more information, link to the FWS digest of the Fish and Wildlife Coordination Act.

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Addressing Habitat Connectivity

In addition to compliance with federal and state endangered species requirements, transportation agencies also are working to address broader concerns related to habitat connectivity and wildlife impacts. Agencies increasingly are pursuing context sensitive solutions that better address potential ecological as well as community impacts from transportation projects.

Reducing wildlife mortality on highways is a continuing concern, both for wildlife conservation and motorist safety. As a result, some states are using structural measures to facilitate wildlife movement at key locations of concern.

For example, a range of structures has been used on highway projects across the nation with varying degrees of success. Some of these include:

  • Fencing;
  • Modified drainage culverts;
  • Stream culverts and bridges;
  • Wildlife underpass bridges and dry culverts;
  • Extended bridges;
  • Viaducts;
  • Wildlife overpasses;
  • Signage; and
  • Motion detectors.

Such approaches can be seen on environmentally sensitive projects, such as US-93 in Montana. This “context sensitive” reconstruction project will include installations of 42 fish and wildlife crossing structures and approximately 15 miles of wildlife exclusion fencing, an unprecedented level of wildlife mitigation effort on a single reconstruction project in North America. The effectiveness of the structures will continue to be monitored. Additional information on the project is available in the US 93 Wildlife Mitigation Preconstruction Synthesis Final Report.

A Wildlife Crossing Toolkit was developed as a searchable internet-based database by a partnership including the U.S. Forest Service and other partners.

In addition to use of structures, a number of states are using habitat restoration or preservation to mitigate for impacts to wildlife or habitat.

More information on impact assessment methodologies and mitigation may be found in NCHRP Synthesis 305, Interaction Between Roadways and Wildlife Ecology: A Synthesis of Highway Practice. Also see Wildlife and Roads, described below.

Additional information is available in the August 2008 Report to Congress: Wildlife-Vehicle Collision Reduction Study and the Wildlife-Vehicle Collision Reduction Study: Best Practices Manual. The Report to Congress focused on tools, methods, and other measures that reduce the number of collisions between vehicles and large wildlife, such as deer, because these accidents present the greatest safety danger to travelers and cause the most damage. The manual builds on the information in the Report to Congress, providing best practices for practitioners.


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Wildlife and Roads

An Internet-based interactive decision guide and resource center, Wildlife and Roads: A Resource to Help Mitigate Roads for Wildlife, was developed as part of National Cooperative Highway Research Program Project 25-27 and is now housed on the Center for Environmental Excellence by AASHTO website. 

This resource provides a wealth of information, including a step-by-step decision guide for practitioners. The decision guide takes users through transportation project stages beginning with planning, through implementation, followed by adaptive management. The final report, Evaluation of the Use and Effectiveness of Wildlife Crossings, summarizes research on the use and effectiveness of wildlife crossings to mitigate habitat fragmentation and reduce wildlife vehicle collisions. The report provides guidelines for the selection, configuration, and location of wildlife crossing types and suggestions for the monitoring and evaluation of their effectiveness and maintenance.

Team members responsible for the project include:

  • John Bissonette, Ph.D, Utah State University
  • Patricia Cramer, Ph.D., Utah State University
  • Keith Knapp, Ph.D., P.E., University of Wisconsin
  • Bhagwant Persaud, Ph.D., M. Eng, Transportation Consultant, Ontario
  • Craig Lyon, M.S.Sc., P.Eng., Ryerson University
  • Ingrid Brakop, Insurance Corporation of British Columbia
  • Trevor Kinley M.E.Des, R.P.Bio and Nancy Newhouse, M.E.Des, R.P. Bio, Sylvan Consulting, British Columbia
  • Sandy Jacobson, MS, USDA Forest Service, Redwood Sciences Lab, California
  • Anthony Clevenger, PhD, Western Transportation Institute, Montana State University

To access the site, link to Wildlife and Roads: A Resource to Help Mitigate Roads for Wildlife.

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State Transportation Agency Practices

Many transportation agencies also are working to address impacts to wildlife and the environment through everyday practices and straight-forward solutions. FHWA has documented hundreds of examples of wildlife and habitat conservation practices on its “Keeping it Simple” database on the Internet.

Wide-ranging actions to protect and enhance wildlife and habitat by state transportation agencies’ construction and maintenance operations also are documented in Environmental Stewardship Practices, Procedures, and Policies for Highway Construction and Maintenance, produced by the National Cooperative Highway Research Program (NCHRP) and the Center for Environmental Excellence by AASHTO.

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Ecosystem Approaches

FHWA, many states and federal review and permitting agencies recognize that watershed and ecosystem approaches to enhancement, restoration, and preservation of aquatic and upland ecosystems can expedite the environmental review process for transportation projects, while maximizing benefit to the environment. 

According to FWS, an ecosystem "is a geographic area including all the living organisms (people, plants, animals, and microorganisms), their physical surroundings (such as soil, water, and air), and the natural cycles that sustain them. All of these elements are interconnected. Managing any one resource affects the others in that ecosystem. Ecosystems can be small (a single stand of aspen) or large (an entire watershed including hundreds of forest stands across many different ownerships)."

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Eco-Logical Initiative

In 2005, a team of federal agencies endorsed a new ecosystem approach to infrastructure development. Dubbed Eco-Logical, the approach encourages agency partners involved in infrastructure planning, design, review, and construction to use flexibility in regulatory processes. According to the agencies, “Eco-Logical puts forth the conceptual groundwork for integrating plans across agency boundaries, and endorses ecosystem-based mitigation - an innovative method of mitigating infrastructure impacts that cannot be avoided.”

The Eco-Logical initiative defines “ecosystem approach” as “a method for sustaining or restoring ecological systems and their functions and values. It is goal driven, and it is based on a collaboratively developed vision of desired future conditions that integrates ecological, economic, and social factors. It is applied within a geographic framework defined primarily by ecological boundaries.”

In a report produced by the interagency team, Eco-Logical is described as follows:

As a means to implement an ecosystem approach, Eco-Logical introduces ecosystem-based mitigation - the process of restoring, creating, enhancing, and preserving habitat and other ecosystem features in conjunction with or in advance of projects in areas where environmental needs and the potential environmental contributions have been determined to be greatest. Ecosystem-based mitigation extends existing compensatory mitigation options by offering a way to evaluate alternatives for off-site mitigation and/or out-of-kind mitigation in the ecologically most important areas as defined by interagency partners and the public. It is a potentially enhanced approach to crediting mitigation that builds on existing approaches. Integrating this new concept with lessons learned from previous experience can allow agencies to capitalize on opportunities for substantial habitat connectivity and wildlife conservation while developing needed infrastructure.

In addition, Eco-Logical recommends an eight-step, nonprescriptive process that can serve as a starting point from which ecosystem-based mitigation decisions can be considered and made. The process, integrated planning, is defined as a course of action that agencies and partners take to combine planning efforts, understand where programmed work will interact, and define ecological resources of highest concern.

No agency acting on its own can effectively implement an ecosystem approach to infrastructure development. Cooperation is necessary to view ecosystems from a range of perspectives and to address a region's highest-priority ecological needs; and since these needs are dynamic and often not fully understood, partners also need to agree on adaptive performance measures to ensure that desired benefits are occurring. By working together, streamlined project development and sound stewardship of natural resources - which are impacted by a variety of competing interests - are achievable outcomes.

For additional information, link to Eco-Logical: An Ecosystem Approach to Developing Infrastructure Projects.

In a related effort, FHWA is promoting planning and environment linkages, an approach to transportation decision-making that considers environmental, community, and economic goals early in the planning stage and carries them through project development, design, and construction. This approach encourages internal and external communication and coordination throughout the decision-making process and encourages adoption of ecosystem-based rather than project-specific approaches. More information is available on FHWA’s Planning and Environment Linkages website and on the Environmental Considerations in Planning section of this website.

FHWA also has identified increasing ecosystem and habitat conservation as one of its “Vital Few Goals.” FHWA has undertaken an initiative to identify “exemplary ecosystem” projects across the country. As of 2006, FHWA had identified 43 transportation-related initiatives in 30 states as “exemplary ecosystem” initiatives, exceeding the agency’s performance goal. For additional information, see FHWA’s Exemplary Ecosystems Initiatives website.

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SAFETEA-LU Section 6001

Coordination among transportation agencies and resource agencies is critical in helping to address adverse impacts to wildlife and habitat.

Transportation legislation enacted in 2005 included provisions addressing transportation impacts on wildlife and ecosystems. Section 6001 of the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU) encouraged interagency cooperation on conservation issues.

The provision requires transportation agencies to consult with resource agencies in the statewide and metropolitan planning process, including a comparison of transportation plans to state and tribal conservation plans, maps, and inventories of natural resources, where available.

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State Wildlife Action Plans

State wildlife action plans, now complete and available for each state, can be used by transportation agencies to help to achieve the goals of SAFETEA-LU Section 6001. These plans evaluate wildlife conservation needs in each state and outline the necessary steps to meet those needs. All plans address eight key elements:

  • Information on the distribution and abundance of wildlife, including low and declining populations, that describes the diversity and health of the state’s wildlife.
  • Descriptions of locations and relative conditions of habitats essential to species in need of conservation.
  • Descriptions of problems that may adversely affect species or their habitats, and priority research and survey efforts.
  • Descriptions of conservation actions proposed to conserve the identified species and habitats.
  • Plans for monitoring species and habitats, and plans for monitoring the effectiveness of the conservation actions and for adapting these conservation actions to respond to new information.
  • Descriptions of procedures to review the plan at intervals not to exceed 10 years.
  • Coordination with federal, state, and local agencies and Indian tribes in developing and implementing the wildlife action plan.
  • Broad public participation in developing and implementing the wildlife action plan.

Additional information is available on the Association of Fish and Wildlife Agencies’ Wildlife Action Plans website.

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Federal Resources

Federal Highway Administration

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U.S. Fish and Wildlife Service

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NOAA Fisheries (NMFS) Resources

  • The Policy for Evaluation of Conservation Efforts [PDF 100kb] when making listing decisions (published March 28, 2003). The policy helps guide other Federal agencies, State, local, tribal, and foreign governments, businesses, organizations and individuals in their efforts to restore populations of declining species before they require the protection of the Endangered Species Act.

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State Resources

State wildlife protection laws vary greatly among the states and regulations and enforcement often are shared among various state agencies within the same state.  Applicable state laws and regulations may be accessed from each state’s website.   

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