Beware of estimates from environmentalists published as headlines. Exaggerations do no one any favours.
The average bird and bat deaths per turbine comes down to 333 – 1,000 deaths annually
I’m no fan of wind farms but these numbers set off my BS detector. I do hate to see such scary but unsubstantiated numbers reported prominently in this way. Bird deaths due to wind turbines are not insignificant, but readers who genuinely care about such things are, in effect, being lied to; many will accept the numbers as fact. They do their cause no favours when they repeat the ‘facts’ (ad nauseam). The rest of us think ‘yeah right’. It is the environmental equivalent of “crying wolf” and it stirs the environmentalist in me because of the harm such irresponsible reporting does to causes which responsibly reporting genuine concerns.
Yesterday’s article in Canada Free Press supposedly reports the presentation of Mark Duchamp, president of Save the Eagles International (STEI), speaking at the First Scientific Congress on Wind Energy and Wildlife Conservation in Jerez de la Frontera, Spain. However it seems to be attributed to Duchamp himself, which instantly sets off alarm bells.
Duchamp has long been claiming that most turbine-associated deaths are grossly underreported and that it is foolish to allow environmental impact assessments to be directed and controlled by wind farm developers.
He claims that a new Spanish guide for evaluating the impact of wind farms on birds and bats by conservation organisation SEO/BirdLife (PDF here in Spanish) vindicates his concerns.
“This is what I have been claiming for years”, laments Mark, who has been banned from ornithology forums as an unwelcomed messenger of bad news. “I am now vindicated, but that won’t save the birds”, he says.
From my limited read of teh report itself (both scanning the Spanish and using Google Translate in parts) it explains how assessments can under report mortality, and sets out good practice in monitoring, aiming to improve the regulation of planning and impact assessments in Spain.
But Duchamp seems to be at odds with both sides. He is quoted elsewhere as saying:
“We cannot count on mainstream ornithologists and bird societies to save bird life from the windfarm threat. These derive much of their income from the windfarm business, and that creates a powerful conflict of interest that clouds their vision and corrupts their conscience.”
This is another reason to take his estimates with a pinch of salt.
The actual headline figure does come from the SEO report – from a box on page 11 ["How many birds are killed at wind farms?", extrapolating from very low rates of detection and supposing high (95%) rates of disappearance].
Nullius in verba of course – I needed to look at a few examples or real assessments. A quick review of actual surveys show typically a tenth of the headline figure. That is bad enough I suppose.
Most of the studies I looked at already included compensation for such things as low detection rate and high ‘disappearance’ of carcases due to predation. This study Impact of wind turbines on birds in Zeebrugge (Belgium) explains the accepted correction – the Winkleman Method:
Used formula to determine the total number of collision fatalities (Na=found number of collision fatalities, Cz=correction factor for search area (= 100/z, where z= the proportion searched surface (in %) of the total surface which should have to be searched), Cp=correction factor for scavenging (= 100/p, where p= the proportion of birds (in %) that were removed by predators during a scavenging-test, Ce=correction factor for search efficiency (= 100/e, where e= the proportion of birds (in %) that were found by the investigator).
A scavenging test, for those who want to know, leaves out fresh carcases for a set period and assesses the loss.
This study concluded there was a “significant impact” on breeding colonies of terns from a wind farm near the Port of Zeebrugge:
The mean number of terns killed in 2004 and 2005 was 6.7 per turbine per year for the whole wind farm, and 11.2 resp. 10.8 per turbine per year for the line of 14 turbines on the sea-directed breakwater close to the breeding colony. The mean number of collision fatalities when including other species (mainly gulls) in 2004 and 2005 was 20.9 resp. 19.1 per turbine per year for the whole wind farm and 34.3 resp. 27.6 per turbine per year for 14 turbines on the sea-directed breakwater.
These figures were not just observed numbers, but corrected figures of up to ~500 birds in one windfarm per year for a single windfarm of 25 turbines. Overall this gave a mortality rate between 0.6- 3.7% on adult breeding pairs across three tern species.
This was in a ‘high fly area’ beside breeding colonies. Could mortality go up from this area’s 20/turbine/year to 1000/turbine/year? That’s nearly three per day per wind turbine. If levels really were that high would detection be that difficult? At least scavengers and predators would benefit. Anyone for a few studies to see how fat foxes are getting?
I suppose there are some who think this is the price we must pay for renewable energy. There are enough bogus numbers spouted in support of wind turbines. I just hope those opposed to wind farms do their own technical due diligence and aren’t taken in by the hyperbole of this article. ‘Null Points’ to CFP for allowing this to be published.