The Bloomington-based John Wesley Powell chapter of the National Audubon Society wants Invenergy LCC to do a little more bird watching.

On Wednesday, Angelo Capparella, the chapter’s conservation chairman and a bird expert at Illinois State University, asked Woodford County zoning officials to require the wind farm company to redo a study of the potential impact its turbines might have on birds.

Capparella plans to repeat the request when McLean County officials discuss the company’s plan next month.

Joel Link, director of business development for Invenergy, said at Wednesday night’s hearing: “We’re willing to analyze that data further. It’s not in our interest to impact habitat negatively.”

Most of the proposed wind farm lies in western McLean County, but the area straddles the McLean-Woodford county line and includes the wildlife-rich Mackinaw River Valley, the Evergreen Lake area and nature preserves adjacent to the proposed wind farm and farther east.

Capparella stressed the Audubon chapter is not against wind farms. The chapter supported another wind farm located in eastern McLean County.

But Capparella said Invenergy’s study, which is mandated, made no mention of the nearby preserves and underestimated the number of birds, including raptors like bald eagles, that migrate through the region each year. “We discovered the assessment document was very incomplete,” Capparella told the Pantagraph.

Both issues might be mitigated by careful placement of the turbines and by setting aside other suitable bird habitat in the area, he said.

Capparella said he knows of no ornithologists at ISU contacted by Invenergy for its study, adding the company did not contact members of the Audubon Society, the ParkLands Foundation, which owns nearby preserves, or the Mackinaw Ecosystem Partnership.

Link said Invenergy used Department of Natural Resources data and a bird atlas as the basis for its study. He said he’s glad local experts are willing of offer more information, and the company is willing to look at it.

He said the company doesn’t want to delay the permit process for that review, however.

In general, wind farms have taken care to locate turbines away from bird migration paths after a much-publicized case in California where many raptors were killed.

Capparella noted state and federal laws require the Illinois Department of Natural Resources and the U.S. Fish & Wildlife Service to conduct a bird impact study a year after the turbines go online.

“We are here to help, not to hinder,” Capparella said. “We are willing to provide what we consider to be accurate data for free so they can do the modeling and make sure the sites are safe and meet the usual standards.

“It could turn out that even with updated information that everything is OK,” Capparella said. “We suspect that could be the outcome. The worst thing that could happen is if the wind farm makes a mistake in sites.”