I like birds, on the whole. I can’t identify more than one or two (maybe just chickens and ducks), but I’m happy to listen to some cheerful chirping in the morning. Certainly I would prefer to listen to a singing bird than to watch it fly, squawking, into the churning blades of a windmill.

I suspect I’m not alone, which would explain the strong emotional reaction windmill-related bird deaths have elicited. It’s been a loud enough public outcry that some projects have been brought to a full halt.

In the United States, the American Bird Conservancy estimates that wind power kills between 10 to 40 thousand birds per year. By any metric, that’s a lot of birds.

The thing is – and I don’t wish to sound insensitive to the lives of our feathered friends – there are a bunch of other things that kill more of them. A lot more.

Every year, an estimated 10,000 migratory birds die between 11 p.m. and 5 a.m. in the city of Toronto after colliding with brightly lit office towers.

According to American statistics, buildings and windows kill up to an astounding 980 million birds each year, and another 80 million die from vehicle collisions. Power lines kill a further 130 million, and yet another four to five million die from hitting communication towers. Ingested pesticides take down an additional 67 million birds. House cats kill 100 million.

These numbers suggest that to match the less-than-fearsome killing power of communication towers alone, Canada would need to multiply its windmills by a factor of 100.

However, nobody is deciding between windmills and communication towers or pesticides. The real choice is between windmills and the forms of energy they propose to replace – oil, coal and gas. If windmills cause fewer avian deaths than these forms of energy, then the “windmills kill birds” argument shouldn’t be the primary cause of staled turbine development projects.

The 1989 Exxon Valdez oil spill, for example, killed between 100,000 and 300,000 birds. Beyond direct deaths, repeated exposure or ingestion of oil can damage populations through reduced health.

Mercury exposure, acid rain and forest dieback – all impacts of fossil fuel emissions – have decimated entire bird populations, and many avian deaths can be generally attributed to climate change.

The population reductions caused by the energy sources that turbines aim to offset massively outstrip deaths from windmills, but don’t carry the same kind of emotional resonance.

"When you look at a wind turbine, you can find the bird carcasses and count them,” explains John Flicker, past-president of the National Audubon Society. “With a coal-fired power plant, you can't count the carcasses, but it's going to kill a lot more birds."

The practical solution is to build very large wind turbines, since these are so high off the ground most birds fly right under them. However, this is sidestepping the issue. The “wind turbines kill birds” argument is propped up by emotional reasoning, and wind power advocates are better served by directly confronting these worries – calling on statistics which place bird deaths in stark perspective – if they wish the argument to really go away. 

Read about more wind turbine concerns in Stu's previous post, "Not In My Backyard".

The Renewable Energy blog showcases weekly posts by Stu Campana on current renewable energy issues. With fascinating projects underway across the country- from community solar power in Milton, Ontario to wind farms in Pictou County, Nova Scotia- Stu will connect these stories through attention to the broader scientific perspective, international political climate, and social variables they involve.