The American Wind Energy Association (AWEA) announced that seventeen of its members have agreed to voluntary operating restrictions to reduce wind turbine speeds in the fall to minimize the number of bats killed during their migration season. According to the AWEA, the new policy results from more than 10 years of research by the Bats and Wind Energy Cooperative and others. It is anticipated that the changes may reduce adverse impacts to bats from operating wind turbines by as much as 30 percent.
According to the U.S. Fish and Wildlife Service (FWS), migratory tree-roosting bats including hoary bats, eastern red bats and silver-haired bats account for the majority of bats killed. These bats are not protected by the Endangered Species Act. The Indiana bat, a federally endangered species, also is vulnerable to wind turbine operations and fatalities have been documented. More information about the impacts of wind farm operations on bat foraging and migration is available at http://www.fws.gov/midwest/wind/wildlifeimpacts/ inbafatalities.html.
The new AWEA policy will involve slowing blade rotations to fewer than one revolution to three revolutions a minute, depending upon blade length, during low-wind speed conditions when bats are most likely to take to the air. The new policy has been announced at a time when there is growing focus on the FWS’ enforcement of the Migratory Bird Treaty Act (MBTA). In a recent decision, the Fifth Circuit reversed Citgo Petroleum Corporation’s conviction on the Clean Air Act and MBTA violations at its Corpus Christi facility holding that the MBTA’s ban on takings only prohibits intentional acts that directly kill migratory birds. In this case, the court determined that the concept of “taking” is limited to deliberate acts done intentionally to migratory birds. This latest ruling appears to set up a spilt in the circuits where in the Fifth, Eighth and Ninth Circuits agree that some intentional act is required for a criminal violation while the Second and Tenth Circuits interpret the MBTA more broadly.
Originally passed in 1918, the MBTA was not intended to address the industrial situations confronting the wind energy today. The law should be amended and/or interpreted in a manner consistent with the Fifth Circuit's recent Citgo ruling to make its application to industry, and particularly the wind farm operations, fair and reasonable.