The FWS issued Interim Guidance on Avoiding and Minimizing Wildlife Impacts From Wind Turbines in 2003.
The FWS also made recommendations on wind farms and bats in February 2011. The Recommendations and U.S. Fish and Wildlife Service's "Draft Guidelines for Land-based Wind Energy Development" are founded upon a “tiered approach” for assessing potential adverse effects to fish and wildlife and their habitats. The tiered approach is an iterative decision making process for collecting information in increasing detail; quantifying the possible risks of proposed wind energy projects to fish, wildlife, and habitats; and evaluating those risks to make siting, construction, and operation decisions. Subsequent tiers refine and build upon issues raised and efforts undertaken in previous tiers. At each tier, a set of questions is provided to help the developer evaluate the potential risk associated with developing a project at the given location. The tiered approach guides a developer‟s decision process as to whether or not the selected location is appropriate for wind development. This decision is related to site-specific conditions regarding potential species and habitat effects.
Briefly, the tiers address:
Tier 1 – Preliminary evaluation or screening of potential sites (landscape-scale screening of possible project sites)
Tier 2 – Site characterization (broad characterization of one or more potential project sites)
Tier 3 – Pre-Construction monitoring and assessments (site-specific assessments at the proposed project site)
Tier 4 – Post-construction monitoring of effects (to evaluate fatalities and other effects)
Tier 5 – Research (to further evaluate direct and indirect effects, and assess how they may be addressed)
This framework allows the developer to determine whether sufficient information exists, whether and how to proceed with development of a project, or whether additional information gathered at a subsequent tier is necessary to make those decisions. (FWS, WSF, 12/10/2011)