Wind turbines – where endangered birds go to die

September 25, 2013 by  
Filed under Wind Energy Tips


SUB: how wind farms slaughter native wildlife, and worsen our health


With a healthy environment at the forefront of everybody’s minds lately, New Zealand is jumping headfirst into wind energy as a supposedly “clean, green” alternative to the current array of ways to generate electricity.

On the surface, it seems ideal. Wind is clean, free and renewable, and is described by the New Zealand Wind Energy Association to be “crucial to New Zealand’s energy future” – but are we looking at it through rose tinted glasses?


Wind farms are being hailed as the eco-friendly power source set to take the country by storm. In reality, while we may be protecting the earth from allegedly harmful toxins and gases, could the wildlife, and perhaps even the public, be suffering?

Wind turbines, while not burning any fuel or emitting any gases into the atmosphere, are an unreliable and expensive energy source. For example, Meridian had planned to construct a 52-turbine wind farm in the Moawhango Ecological District, an area which its own engineering experts admitted would have a capacity factor of only 36%, according to the Rangitikei Guardians, a group set up to oppose industrial wind schemes and educate the public on the impact. Furthermore, wind turbines also pose a serious threat to native New Zealand bird species, as well as our dwindling population of bats through the risk of collisions, habitat loss, and internal damage from changes in air pressure.

Research on bird strike at wind farms in New Zealand is pitifully minimal, and while companies looking to build wind farms are required to evaluate the area they wish to build in to see how it will affect the wildlife, proper studies into how many birds and bats are killed by them have not been done.

International studies, however, paint a worrying picture.

In Spain, the Spanish Ornithological society estimates that up to a shocking 18 million birds are killed annually by the country’s 18,000 turbines. Marc Bechard, an American biologist, told Nature “A blade will cut a griffon vulture in half”.

New Zealand power companies say nearly 500 wind turbines are currently operational, with more under construction. If a million birds are being killed by every thousand wind turbines in Spain, it can be estimated then that New Zealand wind turbines may be killing 200,000 to half a million birds annually.

A Wisconsin University study notes that while the turbine blades appear to be moving deceptively slowly, at the tips the speed can reach up to 280km/h. Many birds die from direct collision with turbine blades, as well as other parts of the turbine such as towers or nacelles- the ballast units behind the blades. It isn’t clear why this happens, but the general belief is that the motion smear from the movement of the blades is too fast for the birds to pick up. It has also been suggested that some birds are unable to divide their attention between hunting prey and scanning the horizon, meaning they do not realise they are flying straight towards an obstacle.

Sherri Lange, who was appointed CEO of the North American Platform Against Windpower in 2011, told Investigate,  “Certain species such as the Whooping Crane in the USA are bound for extinction as turbines continue to proliferate along major migration corridors.  There is so much cover-up and fraud [about] the dead birds and bats that it is hard to fathom in this day and age”.

The debate on the topic is split down the middle. Many believe that the number of birds killed by wind turbines is insignificant compared to those killed by cars and other man-made structures. It is possible, however, that the number is not being correctly represented.

“Searchers (who do the dead bird and bat counts for the developers) are told to bury excess of what certain numbers they are told to recover in their counts,” says Lange. “They are also given scant areas, or lesser populated areas, to search in.  Much of what they see and count is left overs, as most has already been scavenged naturally.  We can only wonder at the real numbers.”

The biggest issue is that these turbines are putting stress on declining species of bird and bat. Altamont Pass in California is home to wind turbines  responsible for killing around 65 golden eagles per year, according to ecologist Shawn Smallwood who has spent a great deal of time working in the area.

One of New Zealand’s native birds at risk from the wind farms is the New Zealand Falcon, our country’s only endemic bird of prey, which is capable of flying at speeds of up to 200km/h. (insert footnote: Gerard Hutching. ‘Birds of prey – New Zealand falcon’, Te Ara – the Encyclopedia of New Zealand, updated 1-Mar-09

Of the three forms of New Zealand falcon, two are classified as nationally vulnerable and one is classified as endangered. The Falcon has already lost much of its habitat due to human interference. Overseas wind farms often have high mortality rates when it comes to birds of prey, due to the height at which the birds fly and the fact that they often fly along the wind pathways that are ideal for wind turbines. This does not bode well for the New Zealand Falcon.

One recent study in California’s Altamont Pass[i] found the turbines were killing 183% of the local owl population. How, you may ask, can a windfarm kill more owls than exist in the area? What researchers found is a harbinger of what may happen in New Zealand – having killed off local birds of prey, the wind farms effectively lure birds from outside the area who come to fill the void. Wind farms are like black holes where owls go to die. Not good news for moreporks.

The study found turbines kill more birds of prey when the land beneath the blades is grazed by cattle or sheep. The dung, say researchers, attracts insects who in turn attract rodents. The more owls, falcons and hawks knocked out of the sky, the more rodents are left to breed, and the more birds of prey arrive looking for takeaways – only to be chopped up by the blades.

Some solutions have been offered for the protection of our wildlife – for example, painting the blades with bright, contrasting patterns could help birds pick up on them more easily. There has not been much research put into this, however, and the protest has been uttered that the result might be an eyesore on the landscape. When it comes to the death of our native bird species, many of them threatened or even endangered, critics ask the obvious question: is that any excuse?

When it comes to bats, the situation is even grimmer. New Zealand is home to only two native land-based mammals. These are the long-tailed bat and lesser short-tailed bat. Both of these species are under threat, and the lesser short-tailed bat is the last of its family. It’s no wonder, then, that any unnecessary deaths of these two species are something to start worrying about.

Bats are occasionally able to avoid collisions with wind turbines, as they use echolocation to watch out for obstacles. The problem with this is that their sonar range is around 60 metres, and flying at a speed of up to 60km/h gives them mere seconds to react to the sudden appearance of a turbine in their path. With a tip travelling at 280 km/h, the bat’s sonar may have detected a clear space that mere seconds later is filled with cold steel by the time the bat reaches the spot. (insert footnote: Veronika Meduna. ‘Bats – Bats in New Zealand’, Te Ara – the Encyclopedia of New Zealand, updated 1-Mar-09)


Even if the bats are lucky enough to avoid a collision, the change in air pressure as they pass the turbine can cause barotrauma. This is a condition akin to the bends that scuba divers get if they ascend to the surface too quickly. The sudden drop in air pressure causes internal haemorrhaging in the bats – the capillaries around their lungs explode. This air pressure change is not something that their echolocation can detect, meaning that bats are at high risk of being killed this way when they fly through wind farms.

Bruce Rapley, an independent scientist who is currently completing his PhD in acoustics and health told Investigate “The air pressure variations caused by the flying blades cause the lungs of bats and small birds to implode.  They find their lungs ‘explode inwards’ and they die an agonizing death by suffocation”.

The death of bats has a wider effect on the ecosystem than one would assume. Bats are highly important to the agricultural industry, as they prey on insects that would otherwise destroy crops, saving the industry millions of dollars. The decline of these bat species would affect ecosystems all along their migration routes.

A study conducted by forest and wildlife ecology professor David Drake and a former master’s student Steven Grodsky in the US looked into the injuries suffered by bats around wind farms. Not only were there the obvious results of bat collisions with turbine blades, but 75% of the bats inspected had broken bones, most of which were in the wings. Most of the bats had fractures, as well as ruptured organs.  A rough 50% of the bats studied were also shown to have middle to inner ear ruptures, and injury that would no doubt disorient the animals. This hints that the estimation of bat deaths from wind turbines is probably incorrect, as disoriented bats would be able to fly away before dying. This means that there will be more dead bats than just the ones found on the ground at wind farms.

It doesn’t stop at direct collisions and barotrauma. The construction of a wind farm can be responsible for the habitat loss of many different species of birds and can interfere with the habitats of bats also.

And, as if the collisions, barotrauma and habitat loss weren’t enough, there’s another thing to be thrown into the mix: wind turbines have been shown to pose a significant threat to human health.

“Wind turbines do, without question, impose a severe impact on

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