What is making birds drop from the sky?

Maria Mounsey- Wildlife Ecology

Benjamin Gontijo- Animal Science

Matthew Bieda- BCT

Shoulders hunched, neck lowered, a predator stalks its prey. Long claws imbed into the soft dirt below. One, two, three steps, a slow lower to the ground, stalking, waiting in silence. A long tail trails behind an athletic and deadly body, softly, it playfully swishes back and forth. Wait. wait. Wait. Locking large, round, golden eyes on its target, a slight pur escapes. Next is a flurry of feathers and cries. As the rustling begins to slow, the predator admires its kill, carefully pacing around it, pawing at the spread wingspan. Ruthlessly, the predator claws at the kill, pondering what to do with it, as the feathery mess lets out one last breath.

You may not have immediately imagined a house cat as a menacing and deadly predator, though to common bird they are exactly that. The inarguable truth of domestic cats is the significantly high number of birds they kill each year. Perspective is the trojan horse in this equation. You may never have seen a cat kill a bird, you may not own a cat, you’re probably thinking, there are a lot of birds to go around. You may think that cats don’t pose a significant threat to bird populations. You may think that, until the number of deaths by cat is compared to something as trivial as the amount of bird and bat deaths by wind turbines.            

Wind turbines are truly a brute force in combating the independence from fossil fuels, though recent arguments have been debating this claim. Many say that wind turbines are killing too many birds, and are a significant threat to bird populations. Wildlife organizations are combative to environmentalists, each claiming which piece of the environment is to be dominantly protected. Birds are being killed by wind turbines,  there is no arguing with that fact. Though in comparison, wind turbines are not a driving force of bird extinction. Wind turbines do not pose a significant threat to birds and bats, instead they are a valuable source of renewable energy. As of a study conducted in 2013, in the United States, domestic cats kill 3.7 billion birds each year (Raasch 2013). In a similar study, it was calculated that wind turbines kill between 200 thousand and 300 thousand birds per year, a startling difference (Koch, 2014). Of course, death is death, and should be mitigated and reduced whenever possible, though it is extremely important to identify the miniscule portion of birds we are losing in comparison to the immensely successful and necessary strides to a greener future.  

Many people claim the use of wind turbine farms cause a significant threat to a multitude of birds and bats annually. There were a number of statistics showing death to birds and bats by wind turbines,  though it is necessary to put this claim into perspective. As mentioned previously by (Raasch 2013), cats cause more deaths to birds annually than wind energy, “Cats that live in the wild or indoor pets allowed to roam outdoors kill from 1.4 billion to as many as 3.7 billion birds in the continental U.S. each year” (Raasch 2013). More than one billion bird deaths is an alarmingly steep idea to conquer. The population of domestic cats in the world won’t drop with the knowledge of this statistic, so it’s hypocritical to think the same should apply to wind turbines. Cats as predators possess a real threat to eliminate populations of bats, “In Rome, a Hypsugo Savii roost disappeared after two years of predation by cats, cases that were brought into shelters totaled 20 fatalities in two years (Ancillotto, Serangeli, & Russo 2013). It seems that bird and bat mortality is being used as a scapegoat for many people to show their disapproval of the very useful wind energy.

Before running into the specifics of wind energy, it’s important to master the basics. A wind turbine is a sizable machine, typically encompassing a wheel which spins due to  large panes being blown by wind, therefore generating electricity that can be redirected. Wind turbines can be used in large scales which harness the energy and direct it towards a power grid or smaller ones which can be used to power a specific home or municipal building (Siemens Energy 2013). Wind turbines have various different designs, each design can be used in different environments from large to small, “VAWTs have been proven to be effective in rooftop and small scale applications” (Kumar et al. 2016). Many times wind turbines are grouped together to create wind farms, in order to generate significant amounts of electricity. This energy is immensely less guilty than that derived from coal. Wind energy is clean, in that no coal is being burned. No pollution is being released or created in the generation of the electricity, creating no greenhouse gas emissions. Wind is also a consistent and renewable source, and isn’t influenced by drought or other significant threats to our natural landscape (Siemens Energy 2013).

In comparison, coal, which ranks third largest of the United States energy sources, is destroying our environment. With the added pressure to figure out better options for the energy crisis that doesn’t involve carbon based fuels, wind energy is a bright spot, “ the cost will reduce nearly 45% for offshore and 25% for onshore wind systems by 2050 due to the continuous research and large investment in offshore wind power technologies” (Kumar et al. 2016). The process of mining coal, one of the two methods of extracting coal, creates deadly acid mine drainage. The Center for Climate and Energy Solutions explains acid mine drainage is created by “a chemical reaction between water and sulfur bearing rocks” which then leaches into rivers, streams, and other bodies of water that used to be major habitat areas and sources of clean drinking water, rendering them toxic and contaminated. Coal is also a large contributor of greenhouse gases, specifically methane. Methane has a global warming potential that is 23 times higher than CO2.  The Center for Climate and Energy Solutions states, “The EPA estimates that coal mine methane contributes 8 – 10 percent of human-made methane emissions worldwide”. With the knowledge that coal is a force to be reckoned with, I think it’s safe to settle on the positive wind that turbines blow.

There are other causes of bird and bat deaths that are more significant than those caused by wind turbines. Mathieu G. Lundy, a researcher at the School of Biological Sciences in the UK, explains that Climate change also has an effect on bats, “Climate influences the biogeography of bats, their access to food, timing of hibernation, reproduction and development, frequency and duration of torpor and rate of energy expenditure.” ( Lundy, Montgomery, & Sherwin, 2012 ). This is so much more than an argument about avian mortality. Climate change is happening because of a constant exploitation of natural resources. We must turn to more energy efficient ways of creating and using energy to slow the effects of climate change for our earth (Lundy et al., 2012). Clean wind energy is an immensely efficient way to benefit the environment. Wind energy is charged with the mortality of many birds and bats, but those deaths  are minimal compared to other causes such as death by cats and buildings in large cities, and especially the mortality rates occurring because of climate change (Lundy et al. 2012). Lundy communicates that birds and bats are at a higher risk from climate change, and we know wind turbines are an efficient way to help mitigate effects of climate change.

The location of wind turbines plays a significant role in determining where it is safe and practical to all associated parties to implement wind energy. During a study to figure out if bats were attracted to wind turbines, the researchers found, “It is important to note that while this is true, over two years of study during migratory seasons only two birds, not bats were ever found dead”, (Jameson & Willis 2014). Wind turbines might attract more bats but there is no evidence to suggest that they play a significant role in their fatalities. It is further mentioned that most bats attracted to wind turbines are migratory, “Lasiurus borealis, Lasiurus cinereus, and Lasionycteris noctivagans, comprise 78% of fatalities at wind energy facilities across North America”, (Korstian, Hale, & Williams 2015). These bat populations are some of the most common bats in the world and their population sizes have always been stable. Tree and cave roosting bats are at a specifically high risk from climate change because of changes in vegetation and fluctuant climates. (Lundy et al., 2012). As for European and North West African bats, Lundy says that 11 species in these areas who have not originally roosted in caves and trees are restricted to do so, and because of this are at risk. All because of the range of changing climates.  Now as we mentioned to help mitigate climate changes, green renewable energy sources must be the future. Wind turbines do this productively, thus benefiting various bat species.

Many question how wind turbines can directly benefit their lives. On first look, it can seem like wind energy companies want to construct these massive structures jutting out into the sky that citizens will look at every day. It is easy to believe wind turbines will disturb the environment and every community near it. These assumptions make it near impossible to believe wind turbines could do any good. Many believe in the common misconception that having wind turbines near a residence will help reduce the cost of electricity. This is not necessarily true. The communities that directly border wind energy turbines might not see a decrease in their electricity rates because the wind energy companies can and most likely will outsource some of that energy to make more money (Hall, D. M., & Lazarus, E. D. 2015). However, there are widespread economic benefits from being the community that houses wind turbines for the wind energy companies. The most important benefit that cannot be understated are jobs and research, which has directly been seen throughout Maine, “[wind energy production] has already brought more than $25 million in research and construction funds for Maine and created 300 construction jobs” (Hall, D. M., & Lazarus, E. D. 2015). The University of Maine spearheaded community outreach programs that developed trust and spread information that wouldn’t normally be available to these communities. A better relationship between communities and wind turbine companies is a plus, especially when there are much worse alternatives. In this sense, both sides of the business are working together to make the wind energy field as profitable and beneficial to both parties as possible.

The key communication factor is that between million dollar companies and prestigious shareholders with the common fisherman or local community town hall. For a long time not enough was done to foster cooperation between both parties and that is why wind energy has stalled for a lengthy amount of time. Many communities in Maine responded to outreach meetings about offshore wind farms and still remember the news of the Cape Wind project. The Cape Wind (located in Cape Cod MA) project has been under development since 2001, but ran into fierce retaliation from wealthy landowners who were not part of the early process, (Hall, D. M., & Lazarus, E. D. 2015). The first impression these communities had of wind energy was disapproving to say the least. Emotional response is the most dangerous factor to a business aspiring to establish a market in a certain area. Emotional and initial responses by citizens are very hard to disprove. Information sharing is very important to how people communicate with each other and the way it is presented can have the biggest effects. The only information made readily available to communities in this situation, was from wealthy landowners. These landowners were dissatisfied with wind energy companies because they did not bother to keep communities informed on the project plans or liabilities. This can often be described as a, “nocebo effect”, where negative expectations lead to negative symptoms even before any experiences occur. (Crichton & Petrie 2015). The University of Maine is well aware of what happened with the Cape Wind project and are working to keep local communities informed and included. The Cape Wind project is a vital source of reflection and should continue to be critically analyzed to better further wind turbine projects. In the future, citizen participation is critical to any turbine movement. People want to feel heard, they want to feel listened to and acknowledged, which will need to happen if the wind industry wants to broaden.

In terms of Maine’s outreach programs, they exercised better communication on a local level. The University of Maine took steps to organize outreach meetings to the public, cushioning the project significantly (Hall & Lazarus 2015). The field of wind energy is a promising and growing industry; it has emerged as one of the leading replacements for carbon based fuels. Thus, communities know eventually there will be no choice but to be involved with wind turbines. The community outreach programs are absolutely pivotal to the resistance encountered by the wind energy movement, progress can be made in years or decades depending on how well each side cooperates with the other. Wind turbines will create job opportunities, will allow for greater sustainability of energy sources, can lower electricity rates for some communities, and will establish a beneficial relationship between local communities and powerful wind energy companies.

Wind energy is far from an established industry at this point in the United States, but it is emerging as one with a bright and windy future. Wind energy has the potential to lower electricity rates for multiple communities depending on location, and also can lead to increased job opportunities. Wind energy does not produce pollution, and does not have a substantial impact upon the environment, instead enhancing and nourishing the environment. Along with solar energy which is rapidly increasing its influence, wind energy has become a frequently mentioned source of energy to replace carbon based fuels. Carbon based fuels are decreasing in supply and are extremely harmful to the environment and produce waste. One of the bright spots in the wind energy field is proposed offshore wind farms for the US. This part of the industry has exponential value in store for the future because it eliminates the first and foremost cause of the resistant audience, the tedious eyesore on everyday life in communities housing the turbines. Wind energy comes with many more benefits for society than any disadvantages it produces as side effects, but there will be ways to mitigate those side effects. When dealing with offshore wind turbines one important problem is addressed, 11 projects for offshore wind turbines are in the advanced stages of development with only two sites under 11km in distance to the shore and all projects will be complete by 2020 (Hall & Lazarus 2015).

Due to the curvature of the Earth, visibility of the turbines is nearly impossible. The curvature of the Earth means that after a certain distance objects can not be seen, in this case beach house owners will not see the turbines. As well as eliminating a disadvantage there is an advantage; due to the higher velocity in wind speeds offshore, there is a huge economic benefit to wind turbines in the US (Hall & Lazarus 2015). Many communities do not look at the wind energy industry favorably, most of this resistance stems from being misinformed simply. As a result an emphasis has been placed on informing the public early in processes to enforce cooperation between local communities and wind energy companies. Outreach meetings started and the common themes included; benefits, infrastructure of the projects, and the impacts on the environment and communities  (Hall & Lazarus 2015). With improved communication to local communities, big companies in wind energy finally begin to work with local support to gain traction on any of the 11 projects alluded to. All the negative side effects that arose due to the Cape Wind project failing to cooperate with landowners early in the process can be fixed. When citizens have negative expectations, they are shown to stick until disproved by applying evidence of positive outcomes (Crichton & Petrie, 2015). Negative expectations will reverse only when completely disproved, putting an emphasis on the importance of public education. With increased cooperation between local communities who are often the biggest resistant audiences, and also the aforementioned benefits of wind energy, there are paths to a better system for wind energy. In order to combat bird and bat deaths, it is proposed that wind energy sites be better evaluated and alternative designs and methods be used. This way we can find alternative sites which can be better suited to harness wind energy while protecting the populations of bats and birds.

When imagining threats to bird and bat populations wind turbines may not come to mind first, but to some groups they are a realistic problem.  Perspective  is very important to truly understand how wind turbines affect their populations.  Deaths of birds and bats due to wind turbines are minuscule when compared to their deaths from the average household cat.  Deaths of birds and bats due to average household cats are minuscule when compared to their deaths from climate change. Wind energy is a great source of renewable energy with a misinformed resistance. Most people do not fully know the full potential and positive benefits wind turbines offer, not only to the environment but also economically. Wind Turbine benefits outweigh any negative effects on bird and bat populations. Although, much research is being done to help wind turbines and various flying organisms to coincide at optimum efficiency. Some people find these wind turbines disturbing to the eye and claim they disturb areas of the environment, but with education and incentives more communities can become cooperative and we can reap the benefits of this valuable source of renewable energy.


Ancillotto, L., Serangeli, M. T., & Russo, D. (2013). Curiosity killed the bat: Domestic cats as bat predators. Mammalian Biology, 78(5), 369-373. doi:10.1016/j.mambio.2013.01.003

“Coal.” N.p., n.d. Web. 18 Apr. 2016.Center for Climate and Energy Solutions.

Crichton, F., & Petrie, K. J. (2015). Accentuate the positive: Counteracting psychogenic responses to media health messages in the age of the internet. Journal of Psychosomatic Research, 79(3), 185-189. doi:10.1016/j.jpsychores.2015.04.014

Haley, A. Sherwin, & W. Ian, Montgomery, & Mathieu G. Lundy (2012). The Impact and Implications   of Climate Change for Bats. ResearchGate. Retrieved from https://www.researchgate.net/publication/228167919_The_impact_and_implications_of_climate_change_for_bats_Mammal_Rev_in_press

Hall, D. M., & Lazarus, E. D. (2015). Deep waters: Lessons from community meetings about offshore wind resource development in the US. Marine Policy, 57, 9-17. doi:10.1016/j.marpol.2015.03.004

Jameson, J. W., & Willis, C. K. R. (2014). Activity of tree bats at anthropogenic tall structures: Implications for mortality of bats at wind turbines. Animal Behaviour, 97, 145-152. doi:http://dx.doi.org.silk.library.umass.edu/10.1016/j.anbehav.2014.09.003

Koch, Wendy. Sept. 2014. Web. 18 Apr. 2016 “Wind Turbines Kill Fewer Birds than Do Cats, Cell  

       Towers.” USA Today. Gannett, 15

Korstian, J. M., Hale, A. M., & Williams, D. A. (2015). Genetic diversity, historic population size, and population structure in 2 north american tree bats. Journal of Mammalogy, 96(5), 972-980. doi:10.1093/jmammal/gyv101

Kumar, Y., Ringenberg, J., Depuru, S. S., Devabhaktuni, V. K., Lee, J. W., Nikolaidis, E., . . . Afjeh, A. (2016). Wind energy: Trends and enabling technologies. Renewable & Sustainable Energy Reviews, 53, 209-224. doi:10.1016/j.rser.2015.07.200

Raasch, Chuck. 30 Jan. 2013. Web. 18 Apr. 2016. “Cats Kill up to 3.7B Birds Annually.” USA Today.

       Gannett, Retrieved from        http://www.usatoday.com/story/news/nation/2013/01/29/cats-wild-birds-mammals-study/1873871/



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