Kilowatts and Killed Bats

Researchers alarmed at large number of dead bats at Tucker wind turbine site

May 09, 2004

By Jim Balow
Staff Writer

The whirling blades of the 44 wind turbines atop Backbone Mountain in Tucker County killed more than 2,000 bats and nearly 200 birds last year, according to estimates from researchers hired to study bird and bat deaths at the site.

While many say the bird deaths are relatively insignificant, the bats are something else, something totally unexpected, and something totally unexplained.

“It’s by far the biggest bat mortality event I know of worldwide, and, as far as I know, the biggest mortality event of any animal,” said Merlin Tuttle, director of Bat Conservation International in Austin, Texas.

Tuttle has been studying bats for 45 years and founded the research group 22 years ago. He read the February report, “A Study of Bird and Bat Collision Fatalities at the Mountaineer Wind Energy Center, Tucker County, West Virginia.” He’s trying to raise money to conduct a follow-up study this year.

Tuttle and other critics have questions about the methodology and conclusions of the first study. He thinks the number of estimated dead bats, as alarming as it already is, could easily be twice as high.

“The reality, I think, is closer to 4,000,” Tuttle said this week. “I believe that to be the consensus of other experts. One of the things experts have said: This sampling wouldn’t pass scientific peer review.”

As required by the state Public Service Commission, the wind power site owners, FPL Energy, hired a consulting firm to study bird and bat deaths in the first year after the turbines went into operation. They hired Paul Kerlinger of Curry & Kerlinger LLC, who has done similar studies at a number of wind power sites across the country.

Kerlinger designed the study and hired Jessica Kerns, a doctoral candidate at the University of Maryland’s Center for Environmental Science Appalachian Laboratory in Potomac, Md., to do most of the field work.

Between April 4 and Nov. 11, 2003, Kerns and an assistant searched the site 36 times, mainly in the spring and fall. Because it normally took two days to search all 44 towers, they spent 61 days in the field. Rounds were spaced about nine days apart in the spring, seven days in the fall.

They walked concentric circles around each turbine and two weather towers, usually just after dawn, looking for dead birds and bats on the ground. They found 69 birds and 475 bats, which they picked up, bagged, froze and sent off for identification. (The species and numbers of dead birds and bats found are shown in tables accompanying this article.)

Most of the birds killed were small common migrant songbirds, including 21 red-eyed vireos.

Very small numbers of other bird species were killed, usually just one or two — a robin here, an indigo bunting there, one red-tailed hawk and two turkey vultures.

Researchers found 33 dead birds on one night. They learned that someone had left on bright sodium vapor lights outside an electrical substation on a foggy night, which they believe attracted birds to their deaths. They discounted those results and warned people to keep the lights off.

Seven species of bats were identified, none of them endangered.

Next, based on the samples, the researchers tried to estimate the total bird kill over the entire year. They performed a searcher efficiency test, where volunteers put out random bird carcasses to see how many the searchers could find — about one in four.

They also did a test to estimate how may dead birds got carried off or eaten by predators. They put all those results into a formula to extrapolate total kill numbers.

Kerns, a biologist who is doing her Ph.D. dissertation on the Mountaineer site, said she is more concerned about the bat kills than the birds. “The birds were pretty minimal ... when you consider the large-scale impacts elsewhere, like windows and cats,” she said.

“Are 150 significant? Red-eyed vireos make up one-half of the deaths. The rest are one or two per species. Red-eyed vireos tend to hit the turbines. I don’t know why. Maybe it’s the higher population.

“I don’t like to find 500 bats. It was quite a surprise. When we started seeing bats last fall, we started putting out feelers to other wind facilities. Is that significant? We don’t know. Most of the bat populations are in the hundreds of thousands or millions.”

Paul Kerlinger, the designer of the study, said he’s been doing bird/turbine research for 10 years. He said the results of the Mountaineer study are “pretty much what I expected with respect to birds. It doesn’t appear there were significant bird impacts.

“With bats, I did not expect the numbers,” he said. “I’m not a bat expert. At other sites, the numbers are not large...

“I don’t like the fact these projects kill birds, but it’s not biologically significant. People say ‘How do you know?’ I say ‘show me the numbers.’

“Bats? I really don’t know the answer to that. I’m not a bat expert.”

Environmentalists in West Virginia are divided on their support of wind energy.

Some say the towers are ugly and a threat to wildlife. Others view it as an alternative, non-polluting energy source.

The West Virginia Highlands Conservancy, after much debate, agreed not to fight a proposed wind project in 2002, but asked the Public Service Commission to set up a process for determining good sites.

Some of its members have formed splinter groups to oppose wind energy projects.

Peter Shoenfeld, chairman of the Conservancy’s wind energy committee, serves on the technical review committee of the Mountaineer bat and bird study.

“I just don’t think the problem with birds amounts to anything compared to large mortality that occurs all the time — running into windows, running into cars,” he said.

A national study in 2001 said between 60 million and 80 million birds die after hitting vehicles and at least 98 million die after crashing into buildings or windows in the United States alone.

“With bats, there does appear to be a serious problem,” Shoenfeld said. “I’m not in a position to say how serious.”

Shoenfeld, a semi-retired mathematician, questioned the study’s methodology.

“I was concerned about the sampling issues, the extrapolating.” He said the number of birds found — 36, not counting the one-time incident — is too small a sample. He wondered why researchers didn’t do a separate predator test for bats.”

He provided follow-up projections that show the bat kill could be twice as high — 4,000 — using formulas used by other scientists.

“Something that’s gone on through the history of the project, I expect there will be unfair criticism of the report.”

Unfair or not, after hearing a reporter was writing about the study, two people called the Sunday Gazette-Mail to offer their opinions.

Dan Boone, who identified himself as a wildlife biologist who owns a farm in Garrett County, Md., questioned the estimate of about 2,000 dead bats. “That in my opinion is a grossly underestimated figure.

“The issue is what is the impact from these facilities if they’re to be located on these ridges, and the failure to do studies before construction. The industry’s own guidelines call for preconstruction studies of wildlife impact.”

Boone noted that the PSC has issued permits for at least two, even larger, wind power facilities in West Virginia before the results of the Mountaineer study were known.

“That’s not to say these facilities can’t be built. We need to be more judicious in siting facilities.”

Linda Cooper of Morgantown, a member of a new multistate group called Citizens for Responsible Windpower, said the group was formed to ensure that wind projects, when built, are done responsibly.

Like Boone, she said she feels the Mountaineer study methodology was flawed. “The level of independence is subject to question. There was no peer review, no statistical analysis. The sampling frequency was inadequate.

“I’m a researcher in human health. I know about the scientific method. If this is the best that can be done, we’re really in trouble.

“The point I’d like to make, the turbines are built on what is considered to be a major [bird] flyway. Others are planned in a flyway. We currently have no siting regulations. It’s asking a lot of the public to finance projects in a major tourism resource without siting regulations.

“It’s difficult,” Cooper said. “Wind power has divided the environmental community. To say this is the best solution, that it’s something to embrace, is not something we should be doing.”

Steve Stengel, a spokesman for FPL Energy in Juno Beach, Fla., said the study’s technical review committee met three or four times to provide peer review of the protocol and results of the study.

Members included people from the U.S. Fish and Wildlife Service and West Virginia Division of Natural Resources.

“You can look at it two ways. If you look at the number of collisions of birds, I think you will find the Mountaineer facility is probably consistent with other facilities across the country. We’re always looking at ways to reduce collisions.

“Clearly the number of bats was higher than what you’d like to see,” Stengel said. “We’re committed to finding out more about bat-turbine interaction.”

More bat research planned this year

“We’re going to continue to study bat-turbine interaction at the Mountaineer facility, specifically this fall,” Stengel said. “We’re still finalizing our plan. Our study will focus on bats this year.”

FPL Energy hosted a two-day conference of bat experts in February to discuss the problem at Mountaineer and other sites. As a result, Tuttle, of Bat Conservation International, and other bat scientists announced an industry-funded alliance to study the problem.

Tuttle said he’s trying to raise $150,000 to fund research this summer and fall in West Virginia. “FPL and us are trying to find a solution. We’re trying to determine what a proper mortality study should be.

“We’ll be going from weekly to daily searches. We need to correlate kills with fog, weather and insect catches to determine what is killing bats on our ridgetops. We have to ask: Are we attracting them in? Are we sonically attracting them? Are insects attracting them?”

He hopes to include radar tests. “I have a commitment from a world leading radar technologist who will be there for a week.”

The dead-bat searches may begin in late July, he said. Last year, researches missed several weeks of the prime bat migration season.

“We didn’t know how big an issue bats were until last fall,” Tuttle said. “Mortality [elsewhere] was so low. Bat searches were so scanty, and done at two-week intervals.”

Bats aren’t as well loved as birds, but maybe they should be, Tuttle says. “Bats are as important at night as birds are by day. They just didn’t get protected by the migratory act.” Some bird species are protected by the Migratory Bird Treaty Act.

“Bats are the primary predator of pests that cost farms and forests billions of dollars of damage annually.”

To contact staff writer Jim Balow, use e-mail or call 348-5102.
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