Saturday, November 17, 2012

Is wind-farm bat kill an urban myth?

Who knows why I got interested? I don’t read James Delingpole, because frankly the guy’s a dill. On the spectrum of “dills who are climate deniers”, his name appears near the “you’re a dill for even wondering what this dill says” end of the scale.

But for some reason I did, and therefore for some reason I came across his obsession about bats being killed by their “lungs imploding” because of air pressure around wind farms.

OK, at first glance, the Mythbusters would start at “plausible”. Barotrauma – the scientific term, which you use if you’re not apparently writing for an audience of idiots who’ll switch off even if you provide the definition in the third par – can happen even to mammals as big as humans, if (for example) we break the rules when diving.

Delingpole avoids the scientific term, either because (a) his science would fit in a matchbox without removing the matches, or (b) he’s a cynical dead shit who’s trying to snow-job readers who don’t do science. Take your pick

Bats are smaller than people, wind farms generate pressure differences, QED bats flying through wind turbine turbulence could die from barotrauma. Or, in the condescending “I know more than you but let’s use small words For the Dummies” tone of Delingpole, their “lungs implode”.

I wish I didn’t obsess about such things, I really do, but after a bit of a trawl through the scholarship, on a Saturday night why-do-I-do-this: it’s probably not true.

The whole “wind turbines kill bats through barotrauma” thing seems to arise from just one paper – this one:

Now, there are some problems with the paper that seems to form the entire scholarly basis for Deligpole’s obsession about barotrauma killing bats around wind farms.

The first is entirely my own work: the number of bats the author says was killed in a single night (188 victims): because by the time the research reached Scientific American, the timeline had stretched to “between July and September”.


That’s significantly more dead bats than any other research identified. For example, this article in Europe said bats are being killed at “unprecedented rates” when the number – without a timeframe in the abstract, and I don’t get paid for this blog, so I didn’t buy the article – yielded a sample of 39 dead bats.

Yes, species, geography and season will impact the numbers, but going from 188 bats in one night, to 188 bats over some months, to 39 dead bats over any unspecified time-frame being “unprecedented” – that should give rise to questions, at least.

Here’s another contradictory number: - which says wind farms in the area of the study kill 20 bats each year.

Now to the substance of the issue.

From – as far as I can find – one paper originating the idea of barotrauma, from which all else have followed, Delingpole has formed an urban mythology that wind farms make bats implode.


This study - - gives barotrauma as a very minor cause of death, comparing dead bats around turbines to dead bats in cities. It also notes that freezing specimens will give misleading results, because frozen cells (for example in the lungs) look a lot like pre-mortem barotrauma.

Bats die because, like birds, they fly into large structures (their sonar, after all, is attuned not to a skyscraper, but to hunting insects).

The foundation of “bat barotrauma” comes from one, single, and as far as I can tell, un-replicated study.

But we all know about cherry-picking the science, don’t we?

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