One of my fondest memories from my first visit to Prince Edward Island in Canada was driving with friends through the eastern part of the island, admiring the bucolic scenery and the mesmerising wildlife. Travelling in a car of “tree huggers”, we were pleasantly surprised at the sight of statuesque wind turbines peppered between patches of woodland. It was exciting to see this small corner of eastern Canada going “green”.
At the time it didn’t occur to me that here was one of Mother Nature’s ironies: one of the most rapidly increasing forms of clean energy can also have deadly consequences for wildlife. Wind turbines – a technology that many view as a necessary component in the fight against climate change – can kill airborne animals, leaving lasting implications throughout the food chain.
From direct collision deaths to displacement from feeding or nesting areas, to habitat degradation or loss, wind farms can have negative impacts on biodiversity, with birds and bats being particularly affected.
The tug-of-war between wind turbines and wildlife preservation is alive and well in Souris, Prince Edward Island in Canada, where The Prince Edward Island (PEI) Energy Corporation wants to add seven new turbines to the 10 currently in place. This would include the use of larger turbines, both in height and in the area swept by their blades. While the province says the greater height of 175 metres, compared with the 125-150m existing turbines in the region, and larger blades allows for more energy production, both the size and the location of the wind turbines are causes for concern to the local PEI Wildlife Federation.
“These windmills will be some of the tallest in the world and will have adverse effects on birds and bats,” says Fred Cheverie, watershed coordinator of the Souris and Area Branch of the PEI Wildlife Federation. “It will be located in an area that is comprised of a series of wetlands that are nesting sites for many species of birds and other wildlife.”
According to Cheverie there are 52 vulnerable species of birds that pass through the area, as well as four endangered species. Bat populations on the island, too, are vulnerable having been decimated by white nose syndrome. “But we have some recovery in this area,” he adds, which would increase the likelihood of bat-turbine collisions.
Cheverie is concerned that the wetlands – which are also an important area for carbon sequestration – will become fragmented by the roads leading to the turbines. He says the site chosen for the wind farm in Souris is located “in the midst of one of the most pristine natural sections of land left on Prince Edward Island.”
The site is next to a section of land called the Red Triangle, which is designated by Canadian Wildlife Service as an area of refuge and protection for migratory birds. PEI Energy Corporation changed the layout of its wind farm to avoid this triangle and insists it is taking steps to reduce its environmental impact, but Cheverie remains concerned about the additional turbines.
More widely, a 2013 study predicted that the expansion of wind turbines in Canada over the next 10-15 years could lead to the killing of approximately 233,000 birds and displacement of 57,000 pairs annually. Another study found wind turbines kill an estimated 140,000 to 328,000 birds each year in the US. It is worth noting that data from 2014 revealed that bird deaths from collisions with power lines in the US numbered 12 to 64 million, but the latter are more prevalent than wind turbines so it is a tricky comparison.
Failing to address the harm posed to wildlife could lead to “a regulatory or economic slowdown in the wind power production that is needed to tackle climate change”, write the US’s National Wildlife Federation’s legal advocacy director Jim Murphy and research associate Lauren Anderson in a 2019 report. Murphy says that while collision risks “are obvious”, it’s essential for wind turbine companies to also be aware of habitat impacts. “Habitat risks involve how wind farm siting impacts wildlife behaviour and activity, such as avoidance, breeding and rearing young,” he says.
In fact, one study led by Maria Thaker, a professor of ecology at the Indian Institute of Science’s Center for Ecological Sciences, found that the ecological impact of wind farms ripples out into the surrounding ecosystem. Conducted in the mountain plateaus of India’s Western Ghats, Thaker and her colleagues discovered almost four times more predatory birds in areas without wind turbines, while observing more lizards around wind farms.
“We found that density and activity of birds were much lower in areas with wind turbines and that meant that lizards were experiencing less predation risk,” says Thaker. “And so, lizards were increasing in number without the typical check of population growth by predation.”
To her surprise, the findings revealed the surrounding food chain had been altered because of the wind turbines. “This can have consequences for other aspects of the food chain, such as other species that birds eat or species that lizards eat,” she says.
Thaker says she doesn’t believe ecosystems at wind farms “are going to be destroyed and damaged beyond repair, but they have shifted the species composition (meaning which species are there) and the way these species respond.” She adds that the death of birds and bats is not the only reason for the environmental concern. “The creation of roads, and human activity under the windfarms disturbs large mammals and so they avoid the area as well.”
It’s why Murphy says finding the right place for turbines is vital. “Good siting is must, as is following the wind energy guidelines developed by the US Fish and Wildlife Service. These guidelines provide a series of best management practices to help avoid, minimise, and compensate for wildlife impacts,” he says. “It is also crucial that wind energy companies comply with key wildlife laws like the Endangered Species Act and Migratory Bird Treaty Act. In practice, this means working with wildlife agencies and stakeholders to identify suitable sites, and using technology and operating practices that reduce impacts on wildlife.”
Once the right site is settled upon, the interventions to save wildlife from wind turbines can go further. One option is shutting down the turbines at key moments. “Technology now allows at risk birds like eagles and condors to be identified long before they come into danger and give operators time to shut down turbines that might pose a risk,” says Murphy.
One of the more promising technologies being used on eagles is a tool called IdentiFlight, which is essentially a robot that can spot and recognise birds with high accuracy. One study found that IdentiFlight detected 96% of the bird flights that human observers saw, and spotted an additional 5.62 times more besides that the birders didn’t see. It misclassified nine out of a total 149 eagles as non-eagles, giving a false negative rate of 6%. IdentiFlight is currently employed at Top of the World Windpower Project in Wyoming, where Murphy says the technology is coupled with human surveillance to reduce bird collisions. “If the threat [of collision] can be determined with more precision, the curtailment can be more targeted.”
In terms of deterring wildlife from the turbines, Murphy says methods that involve acoustics “are showing promise at keeping bats from sites where they could collide with turbines”. One solution includes mounting Ultrasonic Acoustic Deterrents, or UAD devices, on the wind turbines themselves. The idea is that these devices make the airspace around the turbine aurally uncomfortable for bats, so they keep away from the turbine blades. Other deterrents include illuminating turbines with ultraviolet light or painting wind turbines purple. While these methods show promise, they also require further testing to prove their efficacy. As Murphy puts it, “the problem is far from solved”.
However, Thaker agrees with Murphy that the most important piece of the puzzle is location. “Co-existence is definitely possible, as long as wind energy companies are keen to minimise environmental impact,” Thaker says. Placing wind turbines on homes and buildings, as well as on land that is not an important wildlife habitat, would not impact the birds and bats so much, she adds. “What we must not do is convert large areas of natural land to wind farms because we’re rapidly running out of areas for wildlife to exist unhindered.”
It’s that fear of losing integral land that occupies Cheverie in his resistance to the new wind turbines in Souris. “These wetlands are composed of black spruce swamps, which are well known as nesting sites of many birds,” says Cheverie. “The freshwater ecosystem at East Lake is home to many waterfowl that nest there, including the blue winged teal, ring necked duck, American black duck and mallard duck, all of which are listed as species of importance by Eastern Habitat Joint Ventures Implementation Plan.”
An alternative might be sought in offshore wind farms, which have increased in popularity, particularly in the UK and Germany. However, Lena Bergstrom, author of a 2014 study on the effects of offshore wind farms on marine wildlife, says that efforts not to disturb the natural habitat are also a key aspect for offshore windfarms. “This means that the planner should take care to not disrupt the natural species composition in the area – minimise the risk of new invasive species, and of prevailing species becoming displaced.”
Areas that are essential for the recruitment or feeding of fish, birds and mammals “should be avoided”, she says. And while often offshore wind farms create permanent exclusion zones for fishing, which might protect marine life, Bergstrom says that careful planning of the landscape is essential to find the best possible spot. Monitoring the local habitat before the windfarm is built can also provide useful data for assessing cumulative effects and planning for mitigation of any negative effects on wildlife.
A spokesperson from the Canadian Wind Energy Association says that wind energy project developers ensure there are mechanisms in place to reduce potential risks to birds and bats, and to better understand impacts these animals, using tools such as its Wind Energy and Bat Conservation Review. Back in Souris, the PEI Energy Corporation says that protecting wildlife will be a critical part of its environmental management plan. “We do our utmost to avoid building on sensitive areas and we are committed to no net loss of wetland function,” a spokesperson for the corporation says. Based on the results from post-construction surveys completed at existing sites, the spokesperson continues, “the minimum estimated mortality proposed site is quite low when compared to the average avian and bat fatality rates. Despite these low numbers, we are committed to surveying the site closely.”
PEI Energy Corporation was not considering adding retrofits, such as radar and GPS to detect incoming flocks, but it did say that the new turbines would include “more features that reduce environmental impact and reduce noise levels”. At present, the windfarm is compiling the results of its environmental impact analysis, and awaiting permits before any expansion work can begin.
While it’s evident that turbines have impacts on wildlife, “wind energy is a critical part of the solution to climate change, which is the biggest current threat to wildlife”, says Murphy. And while studies have proven wind energy has impacts on ecosystems, Murphy says he believes that these impacts can be reduced to acceptable levels.
Which is a relief considering our planet is in trouble; almost daily we are exposed to dizzying facts, figures, and images about the climate crisis and multiple species of wildlife dying out. Undoubtedly climate change is our earth’s most imminent threat, and with wind energy helping to reduce greenhouse emissions, it’s no surprise that it continues to increase globally from Africa, to America, to Australia.
Perhaps the debate over the wind farm expansion in Souris, can best be seen as a reminder that there is no simple quick fix to save the planet. But with careful planning of sites, the development of urban windfarms, and new deterrents to prevent collisions, reducing carbon emissions with the help of wind could cost fewer animal lives.