Are Wind Turbines Really a Threat to Birds?

Image: Getty Images

With the concern over climate change and its effects only multiplying, along with the rising energy demand, harnessing energy from renewable sources is a must. Wind is arguably one of the most important renewable energy sources that the world must take advantage of to decrease reliance on energy from fossil fuels. In the United States, the nationwide share of wind energy in 2020 was 8.4%, a massive increase from 20 years ago in 2000 when this figure was just 0.1% (Wind Electricity). More wind farms are sprouting up in many areas across the US and the world because as wind energy technologies have advanced, costs have gone down. Many of these technologies still face challenges that need to be addressed, so that wind energy utilization becomes widely accepted and implemented around the world. One of the chief criticisms of wind turbines by both climate change deniers and concerned environmentalists is that wind turbines negatively impact wildlife. Though wind energy may pose a threat to wildlife and marine life, researchers are continuously developing new technologies, regulatory guidelines are becoming stricter, and other concerns, namely climate change, are causing greater harm to birds overall.

Compared to climate or other human constructions, wind turbines are not at all a significant cause of bird deaths overall. According to the US Fish and Wildlife Service (FWS), wind turbines contribute to an average of 234,012 bird deaths in the US per year (Threats). But this should be taken into perspective. Approximately 3 billion birds die annually in the US, so wind turbine deaths are only a very small fraction of a percent. Further, when compared to the 2.4 billion bird deaths or 80% of all deaths that cats cause, it can be seen that wind turbines do not pose a significant threat (Threats). Though bird deaths caused by oil pits are also minimal, at 750,000 deaths, nonrenewable resources pose a higher risk to birds than do wind turbines (Threats). Yet, these numbers do not consider the effects of climate change like habitat loss due to land conversion. One study estimates that with current global warming projections, by 2100, 900 bird species will experience an over 50% reduction in range; range means a decrease of livable habitat area (Jetz). FWS states that "habitat loss is thought to pose by far the greatest threat to birds, both directly and indirectly, however, its overall impact on bird populations is very difficult to directly assess." So while there may not be exact figures, ultimately, climate change reducing the area of livable habitats for birds will have a much more destructive effect on bird populations than wind turbines. Climate change is fueled by anthropogenic carbon dioxide emissions, 25% of which are generated by the energy/electricity sector in the US (Sources). Shifting the energy sector away from fossil fuels towards renewable energy is critical to hinder the effects of climate change and to prevent bird deaths. 

Technologies and strategies are being developed to reduce the number of birds who fly into wind turbines. Throughout their evolutionary history, birds flew at the height of many wind turbines through mostly unobstructed, empty skies. Because wind turbines have only recently appeared on their evolutionary timeline, birds are not well equipped to recognize the large blades as something that they need to fly around. The blades are spinning quickly, at about 300 kilometers per hour and they are white. The rapid spinning motion of the white blades creates a smearing effect in the sky that can make blades harder to spot for birds. A 2020 study by a Norwegian research group offers a straightforward way to minimize bird collisions. The study suggested that implementing visual cues for birds may improve the visibility of the turbines for birds, thus giving them a chance to avoid collision. The visual cue they tested was color: they painted one blade of wind turbines black because previously lab experiments indicated that this would reduce the smearing effect resulting from white blades (May). The study concluded that the fatality rate of birds, especially birds of prey, had dropped by over 70% in the turbines with one black blade compared to traditional all-white turbines (May). Although this was "resource demanding given that they had to be painted while in-place," but "if implemented before construction, this cost will be minimized" (May). So, since wind energy is yet to become a dominant stream of energy, most wind farms have yet to be built, meaning that the black paint approach could be more cost-effective as more wind farms are built. And for the wind farms that are already operational and have high bird collision rates, this method can still be applied without making any drastic changes to the wind farm itself. Therefore, while this method may be a bit costlier at existing wind farms, it still has the potential to be implemented there, as well as at new projects, making it quite a versatile solution.

Image: Audubon

Another technology that can be applied at new or existing wind farms is a monitoring system called IdentiFlight. The system uses artificial intelligence and high precision optical technology to detect birds flying nearby and "determine 3D position, velocity, trajectory, and protected species of interest, all within seconds of detection" (How Does). Then, the tower-mounted optical units combined with algorithms to identify flying and then shut down turbines if the bird's speed and trajectory indicate it is on a collision path with the turbine; in total, the turbine is usually slowed for only two minutes. The Identiflight system was initially tested at the Top of the World wind farm in Wyoming. An independent study comparing an area of turbines without Indentiflight towers installed to an area without them, found that after IdentiFlight was installed at the Top of the World wind farm, "the number of fatalities at the treatment site declined by 63% between before and after periods while increasing at the control site by 113%. In total, there was an 82% reduction in the fatality rate at the treatment site relative to the control site" (McClure). According to IdentiFlight, while their system does slow down wind turbines when a bird is detected in a kilometer's radius, "energy production loss is minimized" (How Does). This system is already showing very promising results, and its artificial intelligence and algorithms only become more accurate the more birds the system detects. Over 100 IndentiFlight towers have already been installed around the world. In addition to the technologies discussed, countless others aim to prevent bird fatalities, and are helping to cut down bird fatalities (How Does). However, even though such methods and technologies - like painting turbines and bird detection systems - are becoming more popular, it is still critical to impose regulation that dissuades wind farms from tolerating high levels of bird fatalities.

Image: Identiflight

 In the United States, existing legislation strongly dissuades companies' wind farms from neglecting wind turbine bird fatalities, holding them accountable for this negligence. The Migratory Bird Act (MBTA) is a long-standing law (over 100 years old). The law is a nationwide implementation of international bird conservation treaties "intended to ensure the sustainability of populations of all protected migratory bird species" (Migratory). The law prohibits killing or inflicting other types of harm onto migratory bird species, including raptors, the category of bird species most often killed by turbines. In 2012, FWS passed stricter voluntary guidelines to respond to concerns about wind turbines causing harm to wildlife, particularly birds. They aim to provide wind farm developers and staff with sound guidelines to help them select a site that will not interfere with wildlife, minimizing any current adverse effects on wildlife from construction and operation (Migratory). Even though the guidelines are voluntary, FWS can refer to them for prosecution under the MBTA; before these guidelines came out, the Justice Department had never prosecuted a wind energy company for not complying with the MBTA (Bennet). Two years after the guidelines were passed, two major wind energy companies - Duke Energy Renewables and PacifiCorp Energy - were prosecuted for bird fatalities at their wind farms. Both companies pleaded guilty - penalties of $1 million and $2.5 million respectively were imposed - and the companies acknowledged that they knew that the wind farms they had constructed were likely to kill birds (Bennet). They were immediately ordered to develop and implement plans to mitigate bird fatalities. The Top of the World wind farm discussed earlier is actually operated by Duke Energy Renewables, so the IdentiFlight technology could be one of their mitigation efforts (Bennet). As these examples demonstrate, it is in wind farm/energy companies' best interest - both economically and legally - to comply with the FWS guidelines.

While bird fatalities due to wind turbines are a current issue, it is essential to consider these fatalities in the broader view. Bird fatalities due to wind turbines are extremely low compared to other causes, namely the impacts of climate change driving habitat loss. And even with these low fatalities, numerous technologies, from the simple to the highly advanced, are being developed and implemented at wind farms around the world to reduce bird deaths. Moreover, the government takes bird deaths very seriously: companies are incentivized to comply with guidelines and legislation to protect birds or face monetary consequences and be forced to adopt mitigative measures. Overall, it is critical for society to not dwell on minor problems like minimal bird deaths due to wind turbines but continue to develop technologies that will help minimize the effects of climate change, which will be devastating to both birds and people.

Works Cited

Bennet, Molly. "How New Technology Is Making Wind Farms Safer for Birds." Audubon, spring 2018,www.audubon.org/magazine/spring-2018/how-new-technology-making-wind-farms-safer-birds.

"How Does a Bird Detection System Work?" IdentiFlight, www.identiflight.com/how-it-works. Accessed 9 Mar. 2022.

Jetz, Walter, et al. "Projected Impacts of Climate and Land-Use Change on the Global Diversity of Birds." PLOS Biology, 5 June 2007, https://doi.org/10.1371/journal.pbio.0050157.

May, Roel, et al. "Paint it Black: Efficacy of Increased Wind Turbine Rotor Blade Visibility to Reduce Avian Fatalities." Ecology and Evolution, vol. 10, no. 16, 26 July 2020, pp. 8927-35, https://doi.org/10.1002/ece3.6592.

McClure, Christopher J. W, et al. "Eagle Fatalities Are Reduced by Automated Curtailment of Wind Turbines." Journal of Applied Ecology, vol. 58, no. 3, 20 Jan. 2021, pp. 446-52, https://doi.org/10.1111/1365-2664.13831.

"Migratory Bird Treaty Act of 1918." U.S. Fish and Wildlife Service, www.fws.gov/law/migratory-bird-treaty-act-1918. Accessed 9 Mar. 2022.

"Sources of Greenhouse Gas Emissions." United States Environmental Protection Agency, www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions. Accessed 9 Mar. 2022.

"Threats to Birds." U.S. Fish and Wildlife Service, www.fws.gov/library/collections/threats-birds. Accessed 9 Mar. 2022.

"Wind Electricity Generation and Share of Total U.S. Electricity Generation, 1990-2020." U.S Energy Information Administration, www.eia.gov/energyexplained/wind/electricity-generation-from-wind.php. Accessed 9 Mar. 2022. Chart.