California Department of Transportation


Last Updated: Thursday, January 5, 2012 12:08 PM

bird - Bioacoustics

Construction and operational road noise effects on avian behavior and health is not well understood. However, it is an issue that has come to light in the last few years causing concern for protected species and project delivery delay. Work has been underway for the past few years to further improve knowledge of this subject and how these issues are addressed.

Through a successful partnership of a Technical Review team and the University of Maryland we have begun to evaluate and provide guidance on this difficult issue facing regulatory and action agencies.

This group sought to develop complete the following:

  • Perform a review and evaluation of existing literature related to the effect of noise on birds
  • Develop preliminary guidance thresholds based on existing information and research to address potential impacts to bird species
  • Develop a strategic research plan to provide data needed to address key uncertainties related to bioacoustic impacts on birds.

Effects of Highway Noise on Birds

Resource agencies such as the U.S. Fish and Wildlife Service (USFWS) and the California Department of Fish and Game (CDFG) are increasingly concerned with noise impacts to birds, especially state and federally listed species. This issue frequently occurs with the marbled murrelet (Brachyramphus maroratus) in Northern California and Least Bell’s vireo (Vireo bellii pusillus) in Southern California. For many transportation projects, mitigation for noise impacts to birds has been required.

To ensure compliance with Federal and State statutes, additional information and justifiable noise thresholds are needed to protect birds, particulary Federal Endangered Species Act (FESA) listed species. Since birds rely on vocal communication, understanding how vehicle generated noise and construction related noise effects birds is important for accurate affect determinations. Dr. Robert J. Dooling and Dr. Arthur N. Popper from the University of Maryland conducted a synthesis and review of existing literature to identify the areas that have been covered in published literature with respect to noise effects on birds. They evaluated the literature and used their own expertise from laboratory studies on birds to develop the guidance document “The Effects of Highway Noise on Birds.” They also used this knowledge and evaluation to highlight areas of research that are needed on the subject. These are included in the guidance document.

A Technical Review team helped with the review process of this document and research needs development. Members of this team included representatives from US Fish and Wildlife Service, CA Department of Fish and Game, Federal Highways Administration, California Department of Transportation, Washington Department of Transportation, and Jones and Stokes. This team provided excellent feedback to the authors on literature sited, presentation of content, anticipated application or use of the document and research needs.

The recently completed guidance document “The Effects of Highway Noise on Birds,” click on the hyperlink to view the document. We hope this document is useful in building your knowledge on the subject.

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