Wind energy has the potential to affect avian and bat species with direct impacts such as collision and barotrauma (tissue damage due to pressure changes), or indirect impacts such as habitat loss, avoidance of habitat, and other behavioral changes. Understanding species behavior in relation to a project area helps facilitate proper infrastructure siting and operation, which can be used as a mechanism to avoid and minimize avian and bat impacts. Formal pre-construction and post-construction surveys provide a more thorough understanding of species behavior than incidental observations. The following standardized pre- and post-construction survey methods are intended to provide for consistent data collection, efficient agency coordination, and wellinformed project development and operation.
The wildlife survey protocols in this document are used to assess potential or verified wildlife impacts from commercial wind projects. The protocol is specific to conditions found within Minnesota LWECS Site Permits and adds detail to the framework established by USFWS Guidelines. Coordination with the agencies (DNR, EERA, and USFWS) is strongly encouraged in the early planning stages of project development to ensure that appropriate surveys, methods, and locations are studied. Agencies can identify potential habitat that should be surveyed, and which protocol(s) should be used in consultation with the project proponent. During both early project planning and periodically as more information is gathered, agencies can provide an estimation of project risk level to avian and bat species.
Sections 1-4 (Bat Acoustics, Avian Flight Characteristics, Avian Grassland Surveys, and Avian Wetland Use Surveys) would be considered pre-construction Tier 3 surveys. Section 5 (Bat & Avian Fatality Monitoring) would be considered post-construction Tier 4 studies in the USFWS Guidelines.
The results of the avian and bat surveys can be used in many different ways including: avoidance of key habitat; micro-siting; determining the need for additional surveys; verification of preconstruction fatality estimates; determining mechanisms to reduce impacts (operational changes); and providing a feedback loop to improve surveys and turbine siting on future projects.
It is important to note that a description of commonly used pre-construction point count avian survey methods is not included in the following sections. The intent of the survey protocols is to encourage the use of limited resources and time in a way that obtains the most useful data for avoiding avian and bat impacts.
Surveys should focus on potential habitat for state-listed species (threatened, endangered, or special concern), federally listed species, and Species of Greatest Conservation Need (SGCN) rather than on habitats and species often targeted with general point counts. General point counts along roads and disturbed areas (i.e. farm fields) are usually not a valid method, when used alone, for determining the presence of listed species. Point counts along roads typically provide a list of generalist avian species that use fragmented habitat.
Project developers also should complete an assessment of specific rare species or other wildlife that may be at risk by development of a commercial wind project. If records or surveys indicate the presence of state-listed or federally listed species, or if species are present at a project site, project developers should coordinate with the Endangered Species Review Coordinator (see DNR Resources for Project Assessment) regarding species-specific survey methods. These methods may be needed in addition to the protocols outlined in this document.
Avian and Bat Survey Protocols for Large Wind Energy Conversion Systems in Minnesota is intended to be updated periodically. This approach reflects the dynamic nature of the understanding of interactions between wildlife and commercial wind farms and allows for inclusion of new information as this field of study develops. Also, if wind energy continues to expand into new ecological areas, such as forested habitats, additional sections may be added to include suitable survey protocols.