For the Birds Radio Program: Minnesota Power to Install Flight Diverters to Protect Whooping Cranes

Original Air Date: Sept. 6, 2010

Minnesota Power will be installing flight diverters to protect flying cranes on their power lines along a 44-mile stretch between the Bison Wind project near New Salem, North Dakota, and a transmission center near Center, North Dakota.

Duration: 6′06″


I’m not the kind of person who pays attention to corporate press releases. But four different phrases in a news item from Minnesota Power last week caught my eye—wind power, Whooping Cranes, flight diverters, and Tom Stehn.

The Duluth-based power company has transmission lines along a 44-mile stretch between the Bison Wind project near New Salem, North Dakota, and a transmission center near Center, North Dakota. Wind power is clean energy, but it has the potential to kill a lot of birds and bats, so I’m still making up my mind about best practices. Researchers studying the effects of wind power find a lot of dead bats beneath the turbines—virtually none with wounds on their bodies. Bats don’t collide with them—rather, they die from something comparable to the bends. Apparently, bat lungs are extraordinarily vulnerable to changes in air pressure from turning turbines. Bats are also succumbing to a mysterious fungal disease called white nose, so as far as I’m concerned, we shouldn’t be proceeding with technology that contributes directly to their decline before we’ve developed sound ways to protect them. Birds collide with turbines in significant numbers, especially during migration, so in my view wind farms should never be placed on major migration routes. And prairie chickens and Sage Grouse abandon grassland areas with wind turbines, so wind farms are inappropriate there. I saw a huge wind farm in Indiana last month as I was driving home from the Gulf—it was sited in a huge agricultural area, the turbines set in fields of row crops, where few birds live anyway. That seems ideal.

Birds are also killed because of mercury and other pollutants released to the atmosphere by coal-burning power plants along with a host of other issues associated with burning fossil fuels, including climate change. Bird deaths at wind turbines are gruesome and unacceptable, but wind power is still an important alternative to fossil fuels. We just need to work harder to find ways to produce power and protect birds both.

Sadly, turbines are not the only bird killers related to wind power. Every year, an estimated 174 million birds are killed at high tension wires, which are abundant at wind farms as well as more traditional power plants. Bird vision is far superior to ours, so there is no question that they can see power lines. But virtually nothing else in nature is a straight line, and apparently the length and narrowness of these wires make it impossible for a flying bird to gauge its distance from one until it’s too late. When a large goose or crane realizes there’s a line right there, the poor bird tends to veer upward, crashing into the wire above. When I was in Nebraska during the 1990s, 17 dead Sandhill Cranes had been collected that day at the Rowe Sanctuary—they’d each collided with the power lines stretching across the Platte River.

Right now, power lines are the number one cause of mortality for the critically endangered Whooping Crane. There’s one surprisingly effective way to reduce kills at power lines—by stringing up little coils of wire called flight diverters at intervals along the lines. Tom Stehn, the US Fish and Wildlife Service’s Whooping Crane coordinator based in Aransas, Texas, someone I personally know and trust, says the three-dimensional coils prevent 50 to 80 percent of all collisions. The world’s entire wild flock of Whooping Cranes—the ones that breed in Wood Buffalo National Park in Canada and winter in Texas—numbers a mere 263 birds right now, and virtually all of them fly through North Dakota, so setting these flight diverters on Minnesota Power’s lines is an important strategy to protect them. Minnesota Power is putting 15,000 of these coils on 22 miles of new line and 22 miles of existing line to protect Whooping Cranes.

It’s very expensive to retrofit wires with these cheap little coils—in this case, those installed on existing line had to be put up via helicopter. But it’s cheap and easy to put them on as new line is being installed. It’s unfathomable to me why power companies don’t install them as a matter of course on every power line. But I’m extremely happy that Minnesota Power decided in this case to use them, and hopeful that they’ll eventually make it their policy to put them up on every line in their entire network.