Wind farms and abuse of statistics: bird edition

When "wind farms are dangerous" really just means "there are a lot of birds".

When dealing with large numbers, it helps to have an idea of the expected order of magnitude. That way, you can know whether it is merely the number which is large, or the thing it's describing as well.

For instance, if I tell you of a country with 140,000 people in long-term unemployment, it's rather important for you to know if I'm talking about the US (population 280 million) or Luxembourg (population 525,000).

That's a test a Spectator article, Wind farms vs wildlife, failed quite badly this week.

The author, Clive Hambler, is a lecturer in biological and human sciences at Oxford university, and quotes a number of statistics to demonstrate how dangerous wind farms are to wildlife. For instance:

Every year in Spain alone — according to research by the conservation group SEO/Birdlife — between 6 and 18 million birds and bats are killed by wind farms. They kill roughly twice as many bats as birds. This breaks down as approximately 110–330 birds per turbine per year and 200–670 bats per year. And these figures may be conservative if you compare them to statistics published in December 2002 by the California Energy Commission: ‘In a summary of avian impacts at wind turbines by Benner et al (1993) bird deaths per turbine per year were as high as 309 in Germany and 895 in Sweden.’

Similar claims are made throughout. Apparently the annual death toll of bats in the US and Canada is "up to three million", "Norwegian wind farms kill over ten white-tailed eagles per year", and so on.

What is missing is any context through which we can examine these numbers. It might change our interpretation of the figures to know that:

Domestic and feral cats have also been considered a major source of anthropogenic-caused mortality with estimates near 100 million annual bird deaths [in the US].

Or that, on roads near wetlands in Canada:

223 birds were killed per mile per year.                                                                                            

Power lines in the US are estimated to kill:

…approximately 130 million birds per year.                                                                                                        

While we're banning things, we may want to keep an eye out for that scourge of the avian world, windows:

97.6 to 976 million bird deaths per year in the U.S. due to collisions with windows… based on an estimated 1 to 10 bird deaths per structure per year from a fatality study in New York.

All those figures come from a 2005 paper by the US Department of Agriculture.

In other words, even with the massive figures from Spain – figures which show deaths per turbine per year two orders of magnitude higher than equivalent figures cited in the above paper, which are based on an assumption that for every confirmed death, there's nineteen uncomfirmed, and which come from a set of guidelines which explicitly concludes wind farms are OK for birds if built correctly (pdf) –  wind farms kill fewer birds than cats, power lines, roads or windows. That comparison would have been rather useful to include in the original piece. With that in mind, the numbers in the piece become less a demonstration of the awesome mortality of wind farms, and more a confirmation that yes, there are a lot of birds in the world.


It's been pointed out on Twitter that I'm not comparing like to like. Spain is smaller than the US, of course. Thankfully, the USDA also estimates the number of birds killed by wind farms in America: between 20,000 and 37,000 a year. I let you draw your own conclusions from the discrepancy.

Wind Turbines in Spain. Photograph: Wikimedia Commons

Alex Hern is a technology reporter for the Guardian. He was formerly staff writer at the New Statesman. You should follow Alex on Twitter.

Photo: Getty Images
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The buck doesn't stop with Grant Shapps - and probably shouldn't stop with Lord Feldman, either

The question of "who knew what, and when?" shouldn't stop with the Conservative peer.

If Grant Shapps’ enforced resignation as a minister was intended to draw a line under the Mark Clarke affair, it has had the reverse effect. Attention is now shifting to Lord Feldman, who was joint chair during Shapps’  tenure at the top of CCHQ.  It is not just the allegations of sexual harrassment, bullying, and extortion against Mark Clarke, but the question of who knew what, and when.

Although Shapps’ resignation letter says that “the buck” stops with him, his allies are privately furious at his de facto sacking, and they are pointing the finger at Feldman. They point out that not only was Feldman the senior partner on paper, but when the rewards for the unexpected election victory were handed out, it was Feldman who was held up as the key man, while Shapps was given what they see as a relatively lowly position in the Department for International Development.  Yet Feldman is still in post while Shapps was effectively forced out by David Cameron. Once again, says one, “the PM’s mates are protected, the rest of us shafted”.

As Simon Walters reports in this morning’s Mail on Sunday, the focus is turning onto Feldman, while Paul Goodman, the editor of the influential grassroots website ConservativeHome has piled further pressure on the peer by calling for him to go.

But even Feldman’s resignation is unlikely to be the end of the matter. Although the scope of the allegations against Clarke were unknown to many, questions about his behaviour were widespread, and fears about the conduct of elections in the party’s youth wing are also longstanding. Shortly after the 2010 election, Conservative student activists told me they’d cheered when Sadiq Khan defeated Clarke in Tooting, while a group of Conservative staffers were said to be part of the “Six per cent club” – they wanted a swing big enough for a Tory majority, but too small for Clarke to win his seat. The viciousness of Conservative Future’s internal elections is sufficiently well-known, meanwhile, to be a repeated refrain among defenders of the notoriously opaque democratic process in Labour Students, with supporters of a one member one vote system asked if they would risk elections as vicious as those in their Tory equivalent.

Just as it seems unlikely that Feldman remained ignorant of allegations against Clarke if Shapps knew, it feels untenable to argue that Clarke’s defeat could be cheered by both student Conservatives and Tory staffers and the unpleasantness of the party’s internal election sufficiently well-known by its opponents, without coming across the desk of Conservative politicians above even the chair of CCHQ’s paygrade.

Stephen Bush is editor of the Staggers, the New Statesman’s political blog.