Maine’s first wind energy project has been stalled by the possibility that its giant, 400-foot-high turbines could kill birds and bats.

Perhaps it was inevitable.

Like hydroelectric dams, wind turbines are a mixed bag ecologically, and nearly every project divides environmentalists, sparking arguments over whether turbines’ ability to provide cleaner air and slow global warming can outweigh the local harm to wild creatures.

California’s Altamont Pass has become infamous as the site where developers did everything wrong, and hundreds of turbines kill a hundred or more birds every year.

But more modern wind developments have reduced bird mortality tremendously. In fact, one such project, in the Allegheny Mountains of Pennsylvania, has seen no bird kills since it was built in 2000.

Yet, despite the gains, Maine Audubon last week filed an appeal of the approval that the Maine Department of Environmental Protection had granted for Evergreen Wind Power LLC to construct 33 turbines atop Mars Hill Mountain in central Aroostook County, citing concerns that the project could prove deadly.

“We’re excited about the potential for wind power in the state … the majority of wind farms don’t cause problems. But when they do, they cause big problems,” explained Jody Jones, a wildlife biologist with Maine Audubon, who recently attended a national conference on wind power and wildlife.

Location, Location

Worldwide, most bird mortality past and present can be attributed to bad placement of turbines.

Unfortunately, the same wind currents that make mountainous areas good wind resources also serve as highways for most migratory birds.

Thermal updrafts, particularly on the northwest side of small mountains, are used by hunting raptors, like hawks and eagles, that glide on the winds.

Altamont Pass is located in one of the nation’s busiest migratory corridors – a bird I-95 – as well as a known feeding area for a large raptor population.

Biologists don’t know that Mars Hill Mountain is in such a corridor, but they don’t know that it isn’t, either.

Most scientists assume that birds migrating through New England probably follow the coastline, far east of Mars Hill, but the research has never been done.

“We just don’t know what’s happening in the interior of Maine,” Jones said.

General surveys conducted by local birders indicate that more than 70 species of birds, including federally protected bald eagles and state-protected golden eagles and peregrine falcons, have been seen near Mars Hill Mountain.

Although none of the protected birds are known to nest any closer than Fort Fairfield, about 20 miles to the north, all are believed to migrate through the area, particularly in the fall, according to the U.S. Fish and Wildlife Service.

Migrating birds are at particular risk of colliding with turbines because they tend to travel at night – and even in daylight some birds’ eyes are not able to discern the blurred outer edges of a rotating blade.

Federal biologists were concerned enough about the potential risk in Mars Hill to propose, at a minimum, three full years of pre-construction study before the turbines are constructed, according to a March letter written by Gordon Russell, supervisor at the U.S. Fish and Wildlife field office in Old Town, in response to a request for technical assistance by Evergreen.

“In the absence of adequate pre-construction data on migratory bird usage of the airspace at the proposed turbine site, Evergreen Windpower proceeds with this project at its own risk,” the letter reads.

“There is a liability there,” Russell said.

Attractive Nuisances?

The turbines in Mars Hill simply pose the lowest possible risk to birds because of their slowly rotating blades and streamlined design, answer the project’s supporters.

“These are not bird-killers,” said Pete Didisheim of the Natural Resources Council of Maine, a wind power advocate.

Studies from throughout Europe and America back them up, showing that old-style wind turbines, with lattice-work construction (like the Eiffel Tower) attract birds by providing irresistible artificial perches.

Modern turbines, like those proposed for Mars Hill, are smooth metal cylinders with no ledges where birds may perch or nest, and mortality at these sites tends to be drastically lower.

There’s no doubt, however, that lights do attract birds to turbines, creating a quandary because safety lighting is required by federal aviation rules.

However, research indicates that changing the color of lights, or choosing lights that flash instead of burning constantly may help to repel birds. Evergreen has promised to do whatever it can, within the bounds of federal law, to reduce the risk.

But over the past five years, a new controversy has emerged as biologists realized that bats were also being killed by turbines. One oft-cited study from West Virginia found that nearly 500 bats were killed by 44 turbines in just three months last fall.

“We don’t know exactly what’s happening with bats. They’re flying around and they’re coming too close, and they’re getting whacked,” said Richard Hoppe, a state wildlife biologist based in Aroostook County.

Northern Maine may have as many as five resident bat species, and information about their lives is even harder to come by than bird data.

Some biologists theorize that the bats are attracted to the insects that gather around the turbines’ lights and are killed when they venture too close to feed.

Others suggest that bats may not use their sonar while migrating, so they cannot sense the turbines’ presence.

“There are a lot of theories, but nobody really understands,” Jones said.

Advocates of wind power counter that no one understands why thousands of migrating songbirds fly head-on into skyscrapers each year, yet construction projects aren’t held up for this risk.

According to the U.S. Fish and Wildlife Service, collisions with buildings kill 98 million birds per year, while communication towers kill another 4 to 5 million – with the estimated figure for windmills at less than 500 annually, with most of those occurring at a handful of badly located sites.

“This is already a developed site, with a ski area, and ATV trails, and six cell towers – some taller than the turbines are going to be,” said Peter Gish of UPC Wind Partners, Evergreen’s parent company, arguing that Audubon is calling for an “unfair standard” for wind turbines as compared to other types of development.

“There is no evidence whatsoever that this is a migratory bird path,” he said.

Gish may be right. Mars Hill may be an ideal wind turbine site with few risks to wildlife, but Jones would like to see scientific evidence to that fact so errors are not made with this first project, harming wildlife and leaving an indelible black mark on wind energy production in Maine, she said.

Initially, the Department of Inland Fisheries & Wildlife had also recommended further study before even allowing the turbines to be built – precisely what Maine Audubon is demanding now.

Ultimately, the state agreed to the project in exchange for Evergreen’s promise to do after-the-fact studies for one year and to address any problems with solutions like shutting down turbines during sensitive times or adjusting lighting.

But despite the department’s OK, the endorsement was tempered with a statement that the Mars Hill project is not to be seen as a precedent for how future wind developments should be handled.

“Just to say that there’s no problem is not a good way to site future developments,” Hoppe said. “You have to come up with some quantitative data to show that there’s no problem.”

Seeing the Forest

Meanwhile, environmentalists, including Didisheim, argue there is plenty of data to move the Mars Hill project forward – data about eight Maine counties violating federal air rules and data about the state’s temperature rising as global warming increases.

If the Earth’s climate changes enough, the bird and bat species Audubon seeks to protect will have died out or moved north, Gish said.

“Wind power can counteract this trend that’s going to be just devastating for all these species,” he said. “They are literally missing the forest for the trees.”

Didsheim, whose organization endorsed the Mars Hill development from the start, said that the project’s minimal cost pales in comparison to its ecological benefit.

A 50-megawatt wind farm like the one proposed for Mars Hill can provide 25,000 homes with clean, renewable electricity. That means hundreds of tons of the pollutants that contribute to smog and global warming removed from the air. In terms of carbon dioxide, the most plentiful greenhouse gas, the benefit is equivalent to taking 17,000 cars off the road, he said.

Consider the acreage that is destroyed when mining companies literally cut the tops off mountains to access coal deposits; consider the war being fought, in part, to guarantee oil reserves in the Middle East; consider the millions of dollars spent to clean up and store the indestructible nuclear waste from now-closed power plants like Maine Yankee – wind power looks better and better, Didisheim said.

“It’s important not to think about wind in isolation,” he said. “There’s no perfect, impact-free way of getting power.”