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:
“How many thousands of birds of all shapes and sizes do the wind farms kill each year? strange that the age doesn’t report this …..”
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:
“As Australia pushes to meet its Mandatory Renewable Energy Targets, wind farms are proliferating across the country…. But overseas experience shows that thousands of rare birds are being killed by turbines each year, and no one has a solution to the problem.”
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.
The picture does not change when we turn to the available evidence concerning impacts of wind energy on threatened species in Australia. Published studies by Cindy Hull, an avian ecologist with Hydro Tasmania, report the documented deaths of birds and bats at two wind farms in Tasmania. A total of 245 bird deaths and 54 bat deaths were documented over a 10 year period and the deaths were overwhelmingly from species classified as not under threat.
Wind energy has a much smaller impact on bird species than other forms of electricity generation. Benjamin Sovacool, a Danish energy policy researcher, reviewed available risk estimates and found that wind power and nuclear power produce 0.3-0.4 bird fatalities per gigawatt-hour of electricity produced, whereas fossil-fuel power produces 5.2 bird fatalities per gigawatt-hour of electricity produced.
As development of wind power in Victoria is displacing brown coal-fired electricity generation, there are good grounds for believing it is bringing relative benefits to birdlife on a state-wide basis.