By Howard Meyerson
Wind power has been a growth industry in Michigan, but one viewed with enthusiasm and concern. Standing high over the landscape, the long-bladed turbines can be seen for miles, powerful symbols of progress and a greener age for electric power production. But as wind’s prominence as an energy source has grown, so has scientists’ and wildlife managers’ concerns about its impacts on birds, bats, and other wildlife.
“The raw numbers (from company reports detailing bird and bat deaths from collisions) are not very high, but it’s hard to know what the actual mortality is,” said Scott Hicks, the East Lansing field supervisor for the U.S. Fish and Wildlife Service (USFWS). “We absolutely want to see more information and encourage every wind development to collect it.”
A 2014 report by the American Wind Wildlife Institute, a partnership of the wind industry, wildlife management agencies, and science and environmental organizations, states: “Fatality rates for most publicly available studies range between three and five birds per megawatt per year… Bat fatality rates can be substantially higher than bird fatality rates, especially at facilities in the Upper Midwest and eastern forests.”
Dead bats and birds
In Michigan, that could translate to approximately 8,760 dead birds each year, and 13,000 bats, according to mortality rates calculated in a 2013 Oklahoma State University study done by Scott Loss, an assistant professor of natural resource ecology and management. The Michigan Public Service Commission reported in August that Michigan has 881 utility-scale wind turbines. Their combined production capacity is 1521.7 megawatts, enough to power approximately 550,000 homes, according to energy industry experts.
Loss examined bird mortality rates across the U.S, taking into account newer monopole designs. They cause fewer bird deaths than earlier lattice designs. His findings, published in the journal Biological Conservation in May 2013, found bird mortality runs from 2.47 to 5.76 birds per megawatt, depending on the region. He estimates the number of birds killed by U.S. wind turbines to be as high as 327,586 birds a year—a number likely to climb.
“The total amount of bird collision mortality at U.S. wind facilities will likely increase with increased wind energy development in the coming decades,” Loss states in his study. “Scaling our estimates to the scenario projected to meet the DOE’s 20 percent goal (a six-fold increase from current generation capacity) produces a mean mortality estimate of 1.4 million birds.”
Hicks and other scientists studying the question say operating wind turbines do not result in enough deaths to cause population declines. In fact, they rank low, according to the USFWS, compared to the number of deaths due to collisions with communication towers, building windows, motor vehicles, high-tension wires, and even predation by cats.
Bird-smart siting practices encouraged
But they do contribute, and so wind companies are encouraged to consider bird-smart siting practices and employ the best management practices and mitigation technologies. Pre- and post-construction monitoring field studies are also encouraged to provide comparative data about those impacts. An 82-page set of voluntary land-based siting guidelines is available to wind developers from USFWS. Michigan has no such guidelines.
“From a wildlife protection standpoint we have little regulatory authority if they build [wind turbines] on private land,” explains Karen Cleveland, the all-birds biologist with the Michigan Department of Natural Resources (MDNR). “If they build on top of an endangered species, or on state land, we can say something. We do tell them that once they have it built and start killing birds they will be in big trouble—and that we’d like to give them advice about how not to do that.”
Cleveland, who has consulted with wind developers, said fewer wind companies are making inquiries these days. The initial push was driven by the 2008 Michigan law that created the state’s Renewable Portfolio Standard, which called for producers to provide at least 10 percent of the electricity from renewable sources by 2015. Tax incentives were offered to those who built. But a 2012 ballot initiative to increase the standard to 25 percent by 2025 was defeated by voters and resulted in a drop off of interest.
“We don’t have a strong public will for increased renewable development,” Cleveland said. “I haven’t had any contact this past year with wind companies. They had to meet a timeline to do it by the 2015 deadline for federal tax incentives. It’s really tapered off a lot since then.”
Most companies do study impacts
Most existing wind power companies work with the USFWS, according to Hicks. Wind farms require a substantial investment. Investors want to know their risks. Few want to be hit with expensive fines for violations of the Endangered Species Act, Migratory Bird Treaty Act, or Bald and Golden Eagle Protection Act. More and more are conducting the recommended pre- and post-construction monitoring studies.
“Early companies may not have shared that information with us, and there are a few who do their own thing, but a lot of them are in contact with us,” Hicks said. “Most are making a good faith effort to follow the guidelines and recommendations. Bald eagles are doing well in Michigan. The number of nests keeps going up.” He knows of only one Bald Eagle that was killed in a collision with a Lower Peninsula wind turbine, along with three Red-tailed Hawks and four Turkey Vultures, 44 birds in total. Those figures come from two post-construction reports and two other preliminary reports.
“That’s not all that was killed,” Hicks said. “That’s only what was found. We don’t know about scavenging or search efficiency.”
The species of greatest concern in Michigan are raptors, night migrating songbirds, and bats, according to wildlife managers. Work is now underway to learn more about pelagic species, those Great Lakes water birds that could be affected by any future proposals to build offshore wind farms.
Dave Luukkonen, a wildlife research biologist at MDNR, has been surveying waterfowl and other species to better understand where they gather and how many there are. His work is part of a region-wide effort by the Great Lakes Wind Collaborative and Great Lakes Commission to frame future research needs for that purpose.
“What we’ve found is that Lake St. Clair has much higher pelagic bird densities,” Luukkonen says. “Peak populations of diving ducks there are 500,000 to 600,000 birds; some flocks are 12 miles long. From a continental perspective, that’s an important area [for birds]. Then there are other areas. Long-tailed ducks make pretty heavy use of Lake Michigan.”
Offshore wind development, Luukkonen explains, presents two types of potential impacts: direct mortality caused from flying into turbines and the indirect erosive effects of birds being excluded from significant staging areas because they do not tolerate the towers’ presence. For diving ducks, like the Canvasback or Scaup, that’s a potentially bigger impact.
“If they build, they may not come,” Luukkonen warns. “That’s important to diving ducks, gulls, and bald eagles. I think the public views wind energy as green, which is true, but there are impacts, and we have some concerns.
“We’re interested in better understanding the potential impacts and minimizing them.”
© 2014 Howard Meyerson
Appears in the November/December Jack Pine Warbler, magazine of Michigan Audubon.