Okay, bird lovers who don’t want to watch rare songbirds thunk into wind turbines have a point—turbines do kill birds. But a new study shows that fossil fuel plants kill more.
It seems weird, kind of, that birds are so bad at flying. You’d think if you had specifically evolved to do something—i.e., skimming through the air trilling a beautiful song of joy—you would also have evolved a sense of how to do it without being killed—i.e., that if a scything blade/giant building is right ahead, don’t wham straight into it. However, the way birds navigate is complex, and frontal vision isn’t necessarily the main sense they’re using. Bird vision has evolved for hunting small animals or insects, so they can be extremely sensitive to movement while less able to detect static objects.
In his forthcoming study in the journal Renewable Energy, Benjamin K. Sovacool of the National University of Singapore proposes a new way of contextualizing the number of bird deaths caused by energy generators. He takes a bunch of studies of wind farms, nuclear power plants, and fossil fuel plants in Europe and North America from 2009 and shows the number of bird deaths per gigawatt hour of energy produced. It seems sort of crude and awful, but if we accept that some bird death due to human activity is inevitable (God, humans—we’re just machines for killing the universe’s happiness, seriously), this seems like a reasonable way to measure efficiency.
Actually, I partially take it back about humans—Sovocool finds that the main thing killing birds is in fact cats. But Sovocool’s study concludes: “Wind farms killed approximately 20,000 birds in the United States in 2009 but nuclear plants killed about 330,000 and fossil fueled power plants more than 14 million.”
The bird deaths caused by wind turbines are the result of collisions—with moving or stationary turbine blades, towers and nacelles (a kind of cover that houses the generator and gearbox), and distribution lines. Wind turbines can affect other flying species too, even if they’re just flying nearby: bats don’t even have to collide with the turbines, as the change in air pressure near the blades can cause internal hemorrhaging in these little guys. And some birds are more vulnerable than others; apparently ducks are especially clumsy fliers, and heavy birds like swans or cranes are particularly prone to collisions.
Like wind turbines, nuclear power plants kill birds through collision. However, Sovocool notes, they also kill birds through uranium mining. Open pit uranium mining can cause the formation of contaminated lakes, which kill hundreds of birds per plant.
Fossil fuel plants—coal, oil, and natural gas—have the same problems. Sovocool points out that these plants “induce avian deaths at various points throughout their fuel cycle: upstream during coal mining, collision and electrocution with operating plant equipment, and poisoning and death caused by acid rain, mercury pollution, and climate change.” Coal mining causes deforestation, which reduces bird habitat and nesting areas. In fact, because fossil fuel has such a heavy impact on the environment as a whole, Sovocool finds that it affects the entire life-cycle of birds, reducing births as well as causing deaths: “Mercury exposure to albatross, falcons, mallards, terns, gulls and other seabirds, woodstorks, pheasants, and bald eagles has been proven in laboratory studies and biological monitoring of real birds to lead to fewer eggs, fewer produced young, and reduced survival rates.”
Then there’s climate change, which is so far-reaching and unpredictable in its effects that it’s hard to estimate exactly how badly it will affect bird populations. Sovocool offers this snapshot of what we can expect: “Looking at the mid-range scenarios in climate change expected by the Intergovernmental Panel on Climate Change, Thomas et al. projected that 15–37% of all species of birds will be committed to extinction by 2050.”
So while wind turbines have their problems, they seem to be better for birds than the other sources of energy on which we predominantly rely. Personally, I’m waiting for the day when cats make up for their inherent amorality by inventing some kind of nap-powered generator. It really seems like the least they can do. Until then, while it’s not fun to watch the endangered bald eagle brain itself against a wind turbine, it’s probably the best way to keep at least a few of them around.
