When I was recently reading an article about wind turbines, it was mentioned that it is a common occurrence for birds to be hit and killed by the blades. So, I did some more reading to find out how many birds are killed by wind turbines every year.

How many birds are killed by wind turbines every year? The results of a recent scientific study concluded that over 300,000 birds were killed by wind turbines every year across the entire globe. 

Even though wind turbines are highly regarded as environmentally friendly alternatives to alternative sources of electricity such as fossil fuels, there has been an increasing amount of reports over the years that the blades are responsible for bird deaths.

If this issue is as severe as it sounds, what is the real environmental cost of being environmentally friendly? 

Related: Sucking The Life Out Of Bats (Are Wind Turbines To Blame?)

The Statistics: How Many Birds Are Killed By Wind Turbines Every Year

Wind turbines generating electricity. Windmills for electric power production. Landscape with wind mills generating energy on the field and colorful blue sky with clouds at sunset in spring in Germany

With all the buzz of wind energy and the positive environmental impacts that wind turbines have left behind in just a few short years, there has been an equal amount of skepticism regarding the new form of clean electricity.

Although wind turbines have been proven to lessen the negative effects that fossil fuels and greenhouse gases have inflicted on the earth, they have also been proven to be the cause of some environmental issues of their own.

These issues deal specifically with wildlife species within the area of the wind turbines, with flying species of animals that are the most targeted by the machines’ massive spinning blades.

 The idea that flying animals such as birds and bats are often killed due to wind energy and a large number of turbines being built all over the world has been around as long as the turbines themselves.

These animals have been known to get caught in the spinning rotor blades that can rotate at speeds of almost two hundred miles per hour,  or even die in mid-air while flying through the area of the blades.

 Although the blades might not ever come in direct contact with the animals that fly past them, the intense turbulence usually creates high levels of pressure throughout the atmosphere, which can become too much for their lungs to handle.

If a small bird is flying through the air for a set period of time and suddenly runs into extremely high pressure, it will be hard for it to adjust to the breathing patterns that would be required to continue flying in that area of the sky.

Additionally, the small lung capacity of these tiny flying animals most likely does not have the range to survive under these breathing conditions in the first place, which will cause their lungs to explode, killing them in mid-air before they are able to reach their destinations. These claims have been the center of multiple case studies and scientific research projects. 

While most of this research has resulted in the same conclusion, different groups of scientists have disagreed on the statistics as well as the action that should be taken to prevent them from growing. 

The study began when a group of scientists studied all of the birds within a specific area and tracked their flying patterns. Those involved in the research became involved in watching exactly where the birds went throughout the day and night and tracked their deaths when they happened to come in contact with the nearby wind turbines.

The final results of the research revealed the statistic that a total of approximately 300,000 birds die from coming in contact with wind turbines every year. 

Hundreds of millions of birds are killed each year by cars and even running into buildings. Over 3 billion birds are killed yearly by house cats. it is a fact that birds are frequently killed and injured by wind turbines, but they are more likely to die at the end of a cat chase rather than by flying into the blades of a wind turbine.

How Wind Turbines Kill So Many Birds

When the topic of bird deaths by wind turbine comes up, it is important to understand the functions and capabilities of the average turbine that can be found in nature almost anywhere today.

Knowing the functions of a wind turbine including how they move their blades, as well as their maximum rotation speeds, will help to paint a better picture of how they can potentially be so harmless to nearby wildlife. 

To start with the basics, wind energy is harnessed and converted into electricity using a machine called a wind turbine. These machines can come in a variety of different sizes, from smaller, residential-scale turbines to even larger utility grade machines that have the ability to provide energy to multiple communities of people all at once.

Regardless of the size of the turbine, most of them will have an average blade length of approximately 50 feet. This number will increase with the individual turbine, but this should give you a general reference for how large the blades can possibly be.

Wind turbines are commonly found in nature within rural areas, usually planted in large fields of grass or among existing farms with cattle roaming around their bases. 

They can also be constructed in mountainous regions and deserts in locations all around the world. Alternatively, wind turbines can also be found inside the ocean. This type of machine is regarded as an offshore turbine and extends out from the ocean off of a base that is located below the water level.

Offshore wind turbines can have adverse effects on various sea animals, including seabirds that fly through the air with the spinning blades of the large aquatic machines. 

Both onshore and offshore wind turbines serve the same purpose: creating electricity from the earth’s infinite source of wind. They both consist of multiple individual components that all work together to complete these functions. One of the biggest pieces on the outside of the turbine is the tower.

The tower is the long vertical structure that holds the turbine’s blades up so it can capture the wind as effectively as possible. This piece can be constructed of solid steel shaped into a cylinder or can have an alternate pattern such as lattice that intertwines thin metal rods similar to a basket weave.

When turbines have a lattice tower, it becomes easier for birds and other flying animals to perch on them or even create nests. This is very dangerous because this keeps them very close to the spinning blades and makes it more likely for them to get injured or killed by the machines when the wind starts blowing. 

The two main components of every wind turbine that completes most of the actions associated with converting electricity are the nacelle and the rotor blades.

As you can probably assume, the rotor blade component is the large piece in front of the turbine that rotates around the tower when the wind begins to blow in order to collect its energy. The look of the blades is most similar to a set of airplane propellors or a spinning pinwheel. 

The blades are attached to the top of the tower and extend toward the top of the sky, the area in which most birds in that area will end up flying. Even though the rotor blades complete the action of turning and producing energy from the wind, there are many more components that allow this to happen.

Without the parts that are located directly behind the rotor in the nacelle, the blades would have no function. Even though it might look like the wind blows and the blades begin to spin around, there is actually a lot more to it than what meets the eye. 

The nacelle is a huge piece that sticks out behind the back of the rotor blades. It sits directly on top of the tower and essentially connects it to the blades.

The nacelle contains hundreds of smaller components that all work together in a system to send signals forward to the turbine blades to let them know when to start and stop spinning. This is also a potential component that local birds could choose to land on when flying through the area. 

The wind turbine’s process of spinning its blades begins when the speeds of the current winds are picked up by a small component called the anemometer. This piece usually sits on top of the nacelle and looks similar to a pair of horizontal helicopter blades.

Similar to an actual helicopter, they will begin to rotate and spin around when they are hit with the pressure of the wind. The function of this piece is to gauge the wind’s torque and send a message through the nacelle to the controller. 

The controller will then send its own message to the high or low-speed shafts, depending on the current speed of the wind, and they will initiate movement outward toward the blades, allowing them to rotate and collect the wind’s energy.

The speed that the controller relays to one of the speed shafts will depend on the minimum and maximum speeds that are programmed into the turbine.

When the anemometer senses a wind speed that is somewhere in between this range, it will give the controller the signal that the blades are safe to start spinning, and from there the controller will determine if they should spin at low or high speeds, depending on the corresponding speeds of the wind. 

If the anemometer picks up on low wind speeds that are barely above the turbine’s minimum, the controller will notify the low-speed shaft to push the movement forward toward the blades so they can carry out the action.

Every wind turbine has internal components built into the machine known as the cut-in and cut-out speeds, which are essentially the minimum and maximums speed ranges in which a wind turbine is able to spin its blades to safely and effectively collect energy from the wind.

As a result, there will be certain times where the blades do not spin at all. However, when the blades are spinning, which is more often than not for most turbines, they can reach very dangerous speeds when it comes to nearby wildlife.

Depending on the size of each individual turbine, they have the potential to reach maximum rotation speeds from one hundred miles per hour to as fast as two hundred miles per hour. 

How Wind Turbines Affect Other Animals 

To further prove the point that wind turbines cause multiple deaths to flying species of animals, there was a study that took place in the Appalachian mountains that tracked and observed the patterns of bats in the area.

General statistics have shown that the majority of bat deaths across the world come from wind turbines alone, especially in this specific location. Even though birds have been reported to suffer over 300,000 deaths each year by wind turbines, this number does not nearly compare to the number of bat deaths that occur due to the same cause.

The results of this study, in particular, showed that bat deaths by wind turbines account for over three-fourths of all possible causes of death that they might run into throughout the year. Even further, millions of bat deaths have been reported annually in connection to spinning wind turbines. 

Similarly to the birds as mentioned above, the bats will come in contact with wind turbines in a variety of ways. The first and most obvious cause of death is when the bats fly through the turbine’s spinning blades and get caught. Alternatively, they can fall victim to the unusually high levels of air pressure that fill the atmosphere surrounding each of the large wind machines. 

Although this study focused on bat deaths, additional information can be taken from the results of this study. More specifically, it was further confirmed that bird deaths by wind turbines are much less frequent than people make them out to be, especially in comparison to the bats.

Although any number of deaths to innocent wildlife that inhabit the areas where wind turbines are placed is much less than ideal, it has been a common argument among wind energy supporters that the death toll on flying animals is not nearly as large as it could be.

In other words, they have compared the statistics of deaths caused by wind turbines with all of the other causes of death that could fall upon these animals and considered the wind turbine crisis to be more of a minor issue.

Over the time that this has become a relevant issue, scientists and animal activists have proposed various solutions to limit the deaths of bats and other flying animals by wind turbines that happen so frequently. 

How Wind Turbines Can Be Improved To Decrease Yearly Bird Deaths 

In addition to the seasons throughout the year in which flying animals have more of a presence flying through the air, there are certain factors that actually attract the animals toward the wind turbines. Most of the wind turbines that are found all across the world today are painted the exact same color: white.

The color white has been chosen for wind turbines for a wide range of logical reasons including the aesthetic and protective properties it can offer to the large machines. However, this choice of color is not so beneficial to the animals that fly around in the area and frequently fall victim to the fatal machines. 

When the sunlight shines down on the wind turbines during the day, the light that is given off is reflected by the light colored paint. The turbines are essentially shining or glowing and stand out against everything else that surrounds them as a result.

This attracts swarms of flying bugs that will either gather in areas as close as they can get to the shiny reflective surface or land on the actual machines. So, how does this affect the bats if there are bugs around the turbines?

Since a common bird diet consists of bugs, they are naturally lured toward the spinning wind turbines in the presence of bugs. They might land on the turbines before they start spinning or completely disregard the rotating blades as they are pursuing their dinner.

This can be detrimental to them, because when animals are anywhere near these machines they tend to have a high probability of serious injury or death, in one way or another.

In regards to the topic of bat fatalities caused by wind turbines, there have been some helpful ideas proposed by various scientists over the years that could potentially lower the fatality rates caused by these machines.

Since it has been acknowledged that the bright white paint color that coats mostly all of the wind turbines that exist across the globe has inadvertently attracted several bugs toward these areas, there have been recent arguments for painting wind turbines an alternative color instead.

The new paint color would have to be much less reflective and be proven to attract fewer bugs to ultimately keep the bats as far away from danger as possible. 

A scientific study was performed specifically to determine which color would be the best replacement for white on wind turbines everywhere. The research began with a series of colored cards that were placed in a row and illuminated by a bright light one by one.

As each colored card displayed its reflection into the air, the number of flying bugs that flew toward it was recorded. The results of the entire study showed that the color purple was the least attractive color in the eyes of the flying bugs out of all other options.

As a result, there have been multiple debates between scientists since this information was discovered, rooting for wind turbines to have a paint makeover and become purple.

However, there are just as many people who are against this adjustment due to the aesthetic properties of purple turbines in nature as well as the potential damage that could be done to the inside of the turbines if the sunlight is not correctly averted away from the machines. 

An additional way to prevent bird deaths by wind turbine throughout each year is to simply turn off the machines during certain seasons when the larger than the usual amount of birds will most likely be flying through the area.

Many scientists that are interested in protecting wildlife have argued that there is virtually no reason for the turbines to remain functioning throughout the entire year, especially during a season where there is barely enough wind to harness and convert. 

Some people would argue that the use of electricity in an entire region couldn’t just stop to protect wildlife, however, this practice actually would not affect the energy supply and demand as much as you would think.

Thanks to new technology that allows wind turbines to compress the excess energy provided by the wind in order to save it for later use, additional energy supply could be harvested throughout all of the other seasons to supplement for the times the wind turbines are not functioning.

A relevant example of ways to protect birds from wind turbines was highlighted in an additional scientific study that was performed on bats. Even though the study did not focus on birds specifically, they are both flying species and the results of the research can be directly related in this case.

The scientific study that was conducted around the relationship of bat fatalities and wind turbines tested how effective certain methods of protecting them would really be. In response to the idea of putting a stop to wind turbine rotation in the event of low wind speeds and seasons where there is not much wind in the atmosphere, to begin with. 

They set out to validate and prove the point that holding the blades of wind turbines in one place more frequently would cut down on the majority of injury and death that bats endure when they inevitably come in contact with the powerful machines.

The conclusion of this specific study was that all bat deaths could be reduced by up to 90 percent if this plan were to go into effect all over the world. This theory had its fair share of opposition, with the popular argument that this would cause a large amount of energy loss.

However, it was further proven throughout the duration of the study that this claim is actually false. This information can be directly applied to the prevention of bird deaths because turning off the machines during bat migrating season would be equally beneficial to all species of flying animals in the area. 

In conclusion, wind turbines have been shown to cause a positive chain reaction in the environments in which they have been placed in recent years. Even though wind energy has been most beneficial, there are certain negative sides of the new wind machines that are not so environmentally friendly, especially when it comes to flying animals like birds.

Are the improvements in the atmosphere worth the consequences that must be faced by the wildlife that come in contact with the turbines?

Related Questions

Do Wind Turbines Have Any Other Adverse Effects on the Environment?

Wind turbines have been rumored to be directly linked to the creation of toxic lakes in China. This is due to the fact that some wind turbines are constructed with inner components that are made of rare earth materials.

These toxic minerals are mined in China, where the entire market for these products is controlled. Even though these products are banned in the United States, they are still frequently used within wind turbines.

On the plus side, wind turbines do not need these specific ingredients in order to be able to function properly, and the machines that do have rare earth materials inside of them account for under two percent of the number of turbines in the entire world. 

How Fast Can Wind Turbines Possibly Spin Their Blades?

Depending on the size and energy capacity of each wind turbine, they have the ability to reach speeds anywhere from 100 miles per hour to 200 miles per hour.

A small residential-scale wind turbine will most likely reach a maximum speed of somewhere around 5 miles per hour, where a large utility-scale turbine with several megawatts of capacity will be closer to the point of 180 miles per hour. 

Is It True That Wind Turbines Are Causing Global Warming?

Although it has been rumored that wind turbines cause global warming, this statement couldn’t be farther from the truth. Wind turbines have been known to move the hot air in the atmosphere down toward the ground level, but this action is not permanent and does not contribute to global warming in any way.

If anything, wind turbines have helped to limit global warming instead of causing more harm to the earth. 

Learn More

If you’re serious about learning more about wind energy, I recommend the Wind Energy Handbook on Amazon. This book is great for both students and professionals, and it holds invaluable information on the subject of wind power.