Oct 29 - Pantagraph

Though concerned, local bird experts continue to support wind farms despite a recent Illinois Department of Natural Resources study that concluded turbines can kill large numbers of bats.

Wind farm companies estimate just two birds are killed by each turbine annually. If true, that fact places turbines far behind other sources of significant avian mortality, such as windows and coal-fired power plants. Earlier national studies have shown turbines kill as few as three of every 100,000 birds.

But, DNR has cited a study done at the Crescent Ridge wind farm project in Bureau County that found its 33 turbines killed three times more bats than birds in a year. Dead birds numbered 31. The tally of dead bats was 93. That finding was consistent with research done earlier in West Virginia.

"Take the most conservative estimates of mortality and multiply them out by the number of turbines planned and you get very large, probably unsustainable kill rates," Merlin D. Tuttle, president and founder of Bat Conservation International, told the Washington Post. "One year from now we could have a gigantic problem."

While more research is done to learn why bats are more vulnerable than birds, local scientists and IDNR urge planners to take care to avoid putting wind farms where bats and birds could be affected.

"The number of bats killed is troubling," said Given Harper, a bird expert who chairs Illinois Wesleyan University's biology department. "Turbines generate sound, heat and electromagnetic fields, but their relationship to bats has not been determined. Other studies suggest that mortality may be higher in bat species that migrate, but there have been few studies that have determined if the bats that have been killed by turbines are local or migratory.

"... Given the location of the turbines near Moraine View (State Recreation Area near LeRoy), I doubt that many bats will be killed there. However, they are just starting to conduct a study there that will give us that information," he said.

"It is all consistent with the wind turbine mortality studies I've seen before," added ornithologist Angelo Capparella of Illinois State University's biology department, who was a spokesman for the John Wesley Powell Audubon Society during hearings on a wind farm proposed for western Mclean County and eastern Woodford County. Audubon supported the project as long as the turbines were carefully placed to avoid routes birds migrate along or places they congregate, such as Evergreen Lake.

"As Jack Darin of Illinois Sierra Club indicated, much more significant mortality occurs with fossil fuel energy production," Capparella said. "Indeed, the windows of our buildings and houses around town kill many more birds not to mention road kill and cats. So, I see no need to alter support of wind projects here ...

"We do want to see studies done of the wind projects here to confirm that (bird) mortality is insignificant, and the companies intend to do that," he continued. "Also, we support studies to assess ways to minimize mortality further through siting and design changes; bat mortality is an issue. In my experience, the industry has been responsive to these concerns."

DNR recommended the General Assembly take no immediate regulatory action.

The U.S. National Research Council released a study earlier this year that indicated two species of bats, the hoary bat and the eastern red bat, are most vulnerable. The Illinois Audubon Society says both only migrate through Illinois and are found here only in summer.

Scott Richardson is Pantagraph outdoor editor. Phone (309) 820- 3227 or email srichardson@pantagraph.com  Read past outdoor and fishing columns or take part in online discussions at www.pantagraph.com/blogs .

Read past outdoor and fishing columns or take part in online discussions at www.pantagraph.com/blogs .

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