Wind Energy Generating facilities have the potential to impact wildlife (including birds) through direct and indirect impacts. Indirect impacts relate primarily to habitat disruption or avoidance behaviors. Direct impacts come primarily from potential collisions. Both of these types of impacts can be avoided, or at least greatly minimized through well informed project design based on thorough environmental surveys, as well as consultation with State and Federal agencies.Heritage’s wind farm siting process begins with the identification of working landscapes (generally agricultural), which inherently offer minimal habitat for wildlife. As project development progresses we engage leading scientists to conduct a broad spectrum of environmental assessments, such as wetland determinations, threatened and endangered species surveys and consultations, and multi-year avian and bat use surveys. In this way, we are able to avoid environmentally sensitive areas and high avian use areas.
The common misconception that all wind farms result in high avian mortality derives from high mortality occurrences at the Altamont Pass Wind Resource Area. A combination of several factors, unique to this area contribute to the high mortality rates at these facilities. The fact is that actual mortality rates at wind farms varies greatly, and amounts to less than 1% of the bird fatalities in the United States. The U.S. Fish and Wildlife Service estimates that hundreds of millions of birds may be killed each year in the United States by anthropogenic activities (power lines, communication towers, poisoning, etc).
House cats alone may be responsible for as many as 39 million bird kills annually. In regard to turbine-related bird deaths, a study by Alfred Manville, with the Division of Migratory Bird Management of the USFWS, estimates that “wind turbines may kill 40,000 or more birds annually nationwide, the majority in California.” While any native bird fatality is unfortunate, these estimates clearly show that wind energy’s contribution to avian mortality in the United States accounts for a minimal percentage (<0.1%) of the bird fatalities per year.
Recent studies estimate that even for conservative global mean temperature increases, between 11% and 34% of species alive today could be threatened with extinction. Wind energy generation has zero greenhouse gas emissions, thus helping reduce the threat of extinction to these species. This is also true of other harmful substances associated with conventional energy sources (such as mercury or lead), which end up being ingested by birds that may feed on contaminated fish from lakes and streams.
Heritage is committed to minimizing the impact of our activities on bird and bat populations by properly planning and siting our wind farms, conducting preconstruction use surveys and post-construction mortality surveys, using only state of the art technology and design, utilizing effective best management practices, and implementing adaptive management.