Abstract
The Fowler Ridge Wind Farm (FRWF) is collectively owned by BP Wind Energy, Sempra US Gas & Power, and Dominion Energy. The project currently consists of 355 wind turbines in three phases in Benton County, Indiana. A post-construction casualty study of bats was conducted by Western EcoSystems Technology, Inc. (WEST) within Phases I and III in 2009, and within Phases I, II, and III in 2010 and 2011. A total of two Indiana bat (Myotis sodalis) carcasses were found, one in the fall of 2009 and one in the fall of 2010. The results of research at the FRWF in 2010 and 2011 completed under Scientific Research and Recovery Permits (TE15075A-0 and TE15075A-2) were used by the FRWF to design an operational monitoring strategy designed to reduce Indiana bat casualty rates. The operational monitoring strategy was implemented at all but nine turbines at the FRWF in the fall of 2012, and included feathering turbines below a cut-in speed of 5.0 meters per second (m/s; 16 feet per second [ft/s]) from August 1 to October 15. The nine turbines not included in the operational monitoring strategy were part of a separate research project conducted by the US Geological Survey (USGS) and Bat Conservation International (BCI).
The primary objective of the 2012 research was to conduct monitoring that provided an accurate estimate of all bat mortality that can be used to reliably determine if a 50% reduction in mortality from control turbines in 2010 has been achieved. A secondary objective of the 2012 research was to detect changing trends in bat mortality over time, including analysis of casualty patterns in relation to temperature and wind conditions.