Synthesis of Noise Effects on Wildlife Populations, 2004

Foreword This report contains a summary of ongoing work on the effects of noise on wildlife populations to date. Because the numbers and/or diversity of species have been used as indicators of the effects of noise, a number of studies that have indicated one or both of these factors for species alongside roads are included, although noise is not specifically mentioned in some of these reports. There is a paucity of information on the response of invertebrates to noise, particularly the levels likely to be encountered along roads. Significant populations of some species are found along rights-of-way, although others such as aquatic forms may be adversely affected; whether by the road itself or by noise is unclear. Existing information (although incomplete) would suggest that fish are unlikely to be adversely affected by noise levels from road. Reptiles and amphibians show some barrier effect due to roads, but there is no clear evidence of a noise effect alone. Recent work has suggested that behavior in burrowing toads may be affected by noise and this will require further study. Birds have received the most study and, in some cases, are strongly adversely affected both in numbers and in breeding by the proximity to roads. In other cases the effect is the opposite and there are reports of many species using roadside habitat in some areas. Large mammals may be repelled by noise, although in most cases the effect appears to be slight to moderate. Small mammals do not appear to be adversely affected by road noise occurring in significant numbers in rights-of-way. There appears to be a physical barrier effect of roads. This report also includes recommendations for future work based on the state of knowledge on the subject. This report will be of most interest to those responsible for environmental impact assessments, road ecologists and those concerned with incorporating environmental concerns into highway planning. The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers' names appear in this report only because they are considered essential to the objective of the document. The Federal Highway Administration (FHWA) provides high-quality information to serve Government, industry, and the public in a manner that promotes public understanding. Standards and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its information. FHWA periodically reviews quality issues and adjusts its programs and processes to ensure continuous quality improvement. PREFACE This …