The Service believes that the weight-of-evidence approach used in the Pinnacle Risk Assessment is an acceptable approach to determine the relative level of impact a particular stressor (i.e., construction activities, collision) will have on a species or group. However, we believe the risk to some groups is higher than determined in the Risk Assessment. In particular we are most concerned about the mortality risk to eagles and unlisted bats from the proposed Pinnacle Wind Power Project, as well as the cumulative effects of multiple wind power projects and other stressors on populations of eagles, other birds, and bats.
It is important for the Service, Pinnacle Wind Force, LLC, and others to work together to gather the information needed to determine feasible and effective methods to reduce collision and mortality risk to birds and bats from wind power projects. Based upon the above analysis, we offer the following recommendations to avoid and reduce anticipated impacts to birds and bats and to document any mortality events or changes to the species populations and diversity due to construction and operation of the proposed Pinnacle wind power facility. These recommendations are based on currently available best scientific information. As new information becomes available, we reserve the right to modify these recommendations.
1. Reduce the amount of forest removal as much as possible to reduce impacts to forest species, including bats and birds. Implement seasonal clearing restrictions that protect Indiana bats and nesting birds.
2. Protect forest habitat off-site to compensate for forest clearing and fragmentation on-site.
3. Avoid impacts to talus and rocky outcrop areas that may be used as roost sites by smallfooted bats and other sensitive species.
4. Follow the guidelines in the Avian Protection Plan (APLIC and Service 2005) to avoid and reduce bird collisions with overhead lines or guy wires.
1. Post-construction mortality monitoring and adaptive management should occur over the operational life of the project. There should be at least three years of intensive monitoring at the beginning of operation. A longer period of intensive monitoring may be needed. Reduced frequency and/or intensity of monitoring may be possible at later stages if early studies document effective operational parameters that significantly reduce bird and bat mortality. Once effective measures are identified, periodic monitoring
should continue throughout the operational life to continue to document that the measures are working as planned. Monitoring of bird and bat mortality should occur during spring, summer, and fall seasons. In addition, winter searches should focus on eagle mortality.
2. Pinnacle Wind Force, LLC should coordinate with the Service and WVDNR on study plans and monitoring prior to initiation of the monitoring.
3. Post-construction assessments should move beyond counts of dead bats and birds in order to identify effective operational parameters that avoid and minimize bird and bat mortality. Studies should investigate if birds and bats are attracted to turbines, and how bird and bat activity and mortality varies with wind speed, direction, persistent weather events, and perhaps other factors.
4. We recommend the use of radar and other monitoring techniques to assess the numbers of birds and bats that are actually flying low enough to be exposed to risk of mortality from wind turbines. We also recommend that the proportion of birds and bats that are successful in passing through the turbine's blade-swept area or that change their flight trajectory to completely avoid the wind turbines be determined. These studies should be conducted during all local climatic conditions and all pertinent daily periods. Changes in
behavior and mortality, as well as methods for predicting mortality events should be reported to the Service.
5. The monitoring plan should include a robust adaptive management component that describes the studies to be conducted, anticipated outcomes (hypotheses to be tested), and a subsequent series of responses addressing those outcomes. Monitoring should be conducted to determine if the selected responses actually result in a reduction of fatalities. Adaptive management trials should begin on some of the turbines in Year 1 of operation.
6. The operation of the facility should be conducted in order to reduce anticipated bird and bat mortality. In particular, there is mounting evidence that bat activity and mortality occur primarily at low wind speeds. Studies should be conducted on the effectiveness of modifying project operations to reduce anticipated bird and bat mortality (such as modifying cut-in speeds, and feathering or stopping blades during the peak of migration or during high-risk weather events). To facilitate data collection in a consistent manner at multiple wind power sites, we recommend that Pinnacle Wind Force, LLC participate in studies similar to the ongoing curtailment study at the Casselman wind power project in Somerset County, Pennsylvania (Arnett et al. 2009).
7. Mortality searches should use dogs to improve detection rates in medium and low visibility habitats (Arnett 2006).
8. Fatality estimates should include complex estimators to account for project site variations, particularly for scavenger activity (Huso 2008); daily searches at some tower sites, as well as weekly searches at other towers (Huso 2008, Kerns et al. 2005); large sample sizes of appropriate carcasses (Arnett et al. 2008, Huso 2008); and corrections for habitat variation (Arnett et al. 2008).
9. Due diligence must be practiced in identifying carcasses. Photographs of all bird and bat carcasses should be taken. Except for bat species of the genus Myotis, other carcasses may be used for determination of scavenging rates and searcher efficiency; however, small tissue samples (such as a feather, toe clip, or small wing punch) should be taken if there are questions about identification. All Myotis bat carcasses should be sent to the WVDNR with the researcher's determination of genus and species, date of collection,
and turbine number where the carcass was collected. Unidentified bat carcasses should be specially marked with a request for identification from WVDNR bat experts. Should WVDNR staff be unable to conclusively identify these carcasses, and/or conclusively determine through process of elimination that the unidentified carcasses are not Federally-listed endangered or threatened bat species, then Pinnacle Wind Force, LLC
should provide funds to the WVDNR for genetic testing at a lab selected by WVDNR and the Service.
10. Survey reports should be submitted to the Service's West Virginia Field Office and WVDNR after each study season and annually by December 31.
11. To help predict raptor impacts, we recommend that Pinnacle Wind Force, LLC fund research on raptor migration patterns in the area, including bald and golden eagles. This could include modeling raptor migration pathways along the Allegheny Front or contributing to ongoing radio telemetry studies by the National Aviary.
12. If nesting bald eagles are found within the project area at any time during the operational life of the project, then the Service's Bald Eagle Management Guidelines (Service 2007) should be followed to avoid disturbance during critical nesting times. We have excerpted pertinent portions of the guidelines for your reference (Enclosure' 1). Due to the risk of
bald eagle strikes once a nest has been established, the Service may recommend that wind turbine operation cease if a nest is found within 1320 feet (400 meters) of a turbine. Additional management considerations may be recommended if it appears that the breeding bald eagles are foraging along or adjacent to the turbine string.
13. If a bald or golden eagle, or a Federally-listed threatened or endangered species is found during a mortality search, then Pinnacle Wind Force, LLC will notify the Service's West Virginia Field Office and WVDNR within 24 hours and discuss how to modify operations to avoid impacts in the future.
14. If it is not possible to avoid impacts to Federally-listed species or to bald and golden eagles, then Pinnacle Wind Force, LLC may pursue incidental take permits under the Endangered Species Act and Eagle Act, respectively. Pinnacle Wind Force, LLC may also. apply for such permits prior to construction.