Ajax wrote on Oct 29^th, 2013 at 8:21am:

Ajax' question intrigued me. As usual, the answer isn't simple.

Do Wind Farms Really Kill Birds?

By Bill King, Lynn Trakell and Emma Bennett

Wind farms are usually accused of making people sick. Now critics claim they also threaten endangered birds. Bill King, Emma Bennett and Lynn Trakell debunk another wind farm myth

The 2013 Victorian duck hunting season began in March with an illegal all-species shoot-up at the Box Flat wetland near the small town of Boort. An informant told the Coalition Against Duck Shooting that around 2000 birds were killed, including around 80 Freckled Ducks (an endangered species), and many other species that could not conceivably have been mistaken for ducks.

A week later, a group from the coalition conducted a two hour search at Box Flat and found 43 dead Freckled Ducks and a total of 156 carcasses, along with 13 wounded birds, which were taken into care. The Department of Primary Industry later reported finding 915 bird carcasses at Box Flat, of which 760 were “game” species.

There are two good arguments against duck hunting that tend to persuade many who accept – or at least tolerate – other kinds of hunting: that it further threatens a number of already endangered species and that it is a particularly cruel sport, with around a quarter of the birds surviving being shot, some later dying of their injuries.

That same concern for animal welfare has entered, honestly or otherwise, into the debate over renewables. If we’re concerned about hunting deaths, shouldn’t we also worry about bird strike at wind farms?

Some readers, commenting on The Age’s story about Box Flat, ran that line:

Quote:

A few weeks later, the ABC’s Occam’s Razor science program ran a segment by Sue Taylor, a Melbourne naturalist and author, that took a similar tack:

Quote:

We agree entirely with calls to value our birdlife more highly – especially threatened species. Whether environmentalists are devaluing our birdlife and treating it as disposable in their blinkered pursuit of clean energy is another matter.

While the Victorian state government has been quite unmoved by the arguments against duck hunting, it has found the arguments against wind power persuasive. Victorian planning laws for wind farms are among the most restrictive in the country.

Unlike the claims that wind power causes illness among people living close to wind farms, claims that wind turbines kill birds and bats do have a basis in fact. The causal process is very straightforward — birds and bats fly into the rotating blades or towers and are killed stone dead.

However, unlike many wind farm critics, we insist that in deciding matters of acceptability, the likely number of deaths does matter. So does relativity with other human activities which impinge on nature — particularly different means of generating electricity — and their impact on birdlife.

So far as we know, no authoritative estimate has yet been made of the total number of birds and bats killed each year in either Victoria or Australia as a whole by collisions with wind turbines.

Emma Bennett, one of the authors of this article, has conducted over 5500 surveys at six wind farms in Victoria. Her data is consistent with less than one bird being killed per turbine per year. The bulk of published studies from overseas are also consistent with these figures. She also found no rare or threatened species killed by wind farms.

Further, small wind farms, like the community wind farm in Leonards Hill, can report zero bird collisions, a finding which is consistent with similar sized wind farms overseas. The science strongly suggests that birds avoid flying through smaller wind farms and simply go around them.

As of the end of 2012, there were 454 turbines in operation in Victoria and 1559 across Australia. In other words, the probable number of birds killed by wind turbine collisions in Victoria for the whole of 2013 would be much lower than the number killed at Box Flat in a single morning of male bonding.

[continued ...]

An edited transcript of an Ockham's Razor broadcast from 5 May 2013.

I have been involved in the investigation of the effect of wind farms on birds and bats for about 13 years at both Hydro Tasmania and Roaring 40s Renewable Energy. I work in this area due to my interest in birds, but also because I worry about our planet. I want to play my part (as small as it is) to reduce the catastrophic impacts of climate change and to protect species.

I have always had a fascination with wildlife, and I want to do my part to assist in its protection. I also love scientific research, in particular the testing of an idea, the challenge of designing a really good study, and perhaps most of all, the analysis of the data once it’s collected.

It’s exciting when you analyse data and see patterns emerge, particularly if they are unexpected. It is particularly surprising when an expected effect is not supported by the evidence, which challenges our assumptions and paradigms. But that’s science—it is designed to be objective.

A good study aims to tease out real patterns from the 'noise', and to make sure that results are not affected by our biases, expectations or other factors. We seek to identify the meaningful trends, the real effects, and let the data speak for itself.

I believe that the best way we can protect our wildlife is to conduct robust scientific research to understand the ecology of a species, the impacts it might be suffering and to investigate if there is anything we can do to minimise the impacts.   

We have been investigating the effect on birds and bats of the Bluff Point and Studland Bay Wind Farms in north-west Tasmania. We have conducted many studies, from monitoring required as part of our State and Commonwealth permits, to targeted studies that we have initiated to try to understand a specific issue, or where possible, to reduce an impact that has been documented.

We have learnt a lot in the last ten years at these wind farms.

Not all species of bird are at equal risk of collision with turbines. We’ve found that only about 20 per cent of the species present at these wind farms are involved in collisions with turbines. The vast majority of collisions involve birds colliding with moving turbine blades, and those at risk are the ones that spend time in the region that the blades move (which is called the rotor swept area).

Modern turbines have a rotor swept area of between 65-115m, meaning the blades sweep through the zone from about 35-125m above the ground, so any birds that don’t fly in this zone are very unlikely to collide (such as those that are only present in trees or shrubs).

Bird collisions with turbines are statistically rare events. What we need to know is whether the number of collisions that do occur could be having a negative impact on the conservation status of a species—that is, will it be pushed closer to extinction?

Similar to birds, there are specific features that make some bat species more at risk of collision. The primary factor again is whether the bat is present in the rotor swept area of turbines.

We have done a lot of work studying how eagles respond to the presence of turbines. A three-year observational study we conducted at these wind farms found that eagles adjust their movements through the wind farm once turbines are installed. They also alter their behaviour in response to whether the turbines were active or not, and under different weather conditions.

The key finding was that eagles demonstrated an awareness of the turbines, and usually actively avoided them.

One of our key areas of current research is determining what are the factors involved in collision risk. Only by understanding these factors can we hope to develop strategies to reduce the risk. 

There is a lot of research into the effect of wind turbines on birds and bats around the world. Until relatively recently, much of this research wasn’t published in the peer-reviewed literature. That’s not to say that the research hasn’t been thorough and appropriate, it just means that it hasn’t passed a formal peer-review process, which provides a layer of credibility. Also, sometimes this material is difficult to access, unlike that in scientific journals.

Part of my job is to keep abreast of all this research. It can be daunting, as there is a lot being done around the world. There are now some excellent scientific conferences held each year on the topic of birds and bats and wind farms, and this sharing of knowledge and findings is critical to the scientific process.

It’s interesting that while some of the issues found at wind farms are the same around the world, some are not. It’s important to remember that assuming what someone found at one site will automatically be found at another doesn’t constitute good science; assumptions need to be tested or strategies trialled.

While a lot has been learnt about wind farm effects, there is more to be learnt. 

Unfortunately in the area of wind farms there is a lot of misinformation and myths, even when scientific evidence exists. Inaccurate information or myths do not progress understanding or, in fact, save species. In my view it only muddies the water, distracts focus and wastes time.

[continued ...]

Great post CrissCross

Wind Turbines are relatively slow moving - they aren't jet engines.

Birds also kill themselves when they strike aircraft, windows, vehicles, eat snail bait, etc

If bird fatalities were made a regulatory requirement for industry There wouldn't be many industries unaffected or even prevented from setting up.

Lets be reasonable folks

(we wouldn't want ALL of us to become filthy smelly putrid clown puppet freak maggots now would we YOU filthy smelly putrid clown puppet freak maggots)

Chimp_Logic wrote on Oct 30^th, 2013 at 11:08am:


Chump....just because you are feeling better one day doesn't mean you can stop taking your medication...ok???

Go and take your pills. Come back when the voices aren't so loud and confusing.

That's bordering on personal insult. The point he's making is that we spend 10 billon dollars on subsidising corporations to buy fossil fuels. 

Wind turbines are private investments. They are mostly owned by large electricity generation concerns.

Now, if the voices in your head are not too strong, maybe you'd like to explain how it's affecting taxpayers?

Rider wrote on Oct 30^th, 2013 at 11:56am:


You didn't know that the fossil fuel and mining industries in Australia receive over 10 billion dolalrs per year in Subsidies and grants???

I agree with you - scrap ALL subsidies

Guess who will squeal the loudest MR RIDER?

Do your own research in who gets what if you're genuinely interested

But of course youre not.

We all know what sort of society youre interested in don't we Mr Rider you putrid clown stench freak