The trouble with turbines: An ill wind

With turbines threatening some bird and bat populations, researchers are seeking ways to keep the skies safe for wildlife.

Marc Bechard turned a worried eye skywards as he walked among the limestone hills at the southern tip of Spain. It was October 2008, and thousands of griffon vultures — along with other vulnerable raptors — were winging towards the Strait of Gibraltar and beyond to Africa. But first they had to navigate some treacherous airspace. The landscape on either side of the strait bristles with wind turbines up to 170 metres high, armed with blades that slice the air at 270 kilometres per hour.

Bechard, a biologist at Boise State University in Idaho, and colleagues from the Doñana Biological Station in Seville, Spain, had been hired to help the birds make it safely past 13 wind farms in Cádiz province. Each time the researchers spotted a raptor heading towards a turbine, they called the wind farm’s control tower. Within minutes the blades slowed to a stop, and one more migrating bird soared past unharmed. Then the turbine swung back into action.

When the biologists weren’t looking up at the sky, they were scouring the ground for carcasses of griffon vultures (Gyps fulvus), Spanish imperial eagles (Aquila adalberti) and other species. The Spanish Ornithological Society in Madrid estimates that Spain’s 18,000 wind turbines may be killing 6 million to 18 million birds and bats annually. “A blade will cut a griffon vulture in half,” says Bechard. “I’ve seen them just decapitated.”

Wind turbines kill far fewer birds in general each year than do many other causes linked to humans, including domestic cats and collisions with glass windows. But wind power has a disproportionate effect on certain species that are already struggling for survival, such as the precarious US population of golden eagles (Aquila chrysaetos canadensis).

“The troubling issue with wind development is that we’re seeing a growing number of birds of conservation concern being killed by wind turbines,” says Albert Manville, a biologist with the US Fish and Wildlife Service in Arlington, Virginia.


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7 responses to “The trouble with turbines: An ill wind

  1. Does any wind turbine company not have the permit to kill eagles?

  2. Seems to me that chicken wire fences on either side of the windmill couldn’t be all that expensive.

  3. I think Obama gave all turbines permits to whack eagles. Not sure how many per turbine……(Seriously, there are permits. Only turbines get them, not any fossil fuels.)
    A 400 foot tall chicken wire fence seems a big much. Plus, eagles can go right through that! (They get hit by trains and recover. They go through windshields and end up alive and in the car and MAD.) So cross off the chicken wire. :)
    On the other hand, why can’t turbines be shrouded like fans? Sure, it’s a bit more money and work, it might look kind of funny, but that should stop the slaughter of raptors. Bats will still explode like little hand grenades, but the raptors will be saved. And isn’t that the important thing–saving the planet and the raptors?

    • “A 400 foot tall chicken wire fence seems a big much.”

      Hey, nothing succeeds like excess!

    • A shroud that could stop a big raptor would probably exceed the load bearing capacity of the tower for current designs. I’m guessing these mods would double the cost of the windmill, making it even more uneconomical.

  4. I guess we just have to go back and redesign the turbines. I know it’s going to cost a lot but we do want to save the birds and the planet, right? :)
    Perhaps we could just use a light-weight shroud that eagles, etc, don’t like the sight of. Anyone up for testing what eagles fine offensive and fly away from???

  5. Catch all the eagles. Put them in cages where only specialist conservationists can get at them.

    Repeat above solution as necessary.

    Problem solved.

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