One thing not factored into the cat numbers is how many birds would be killed in a non-suburban, non-house cat habitat anyway. That is, birds are preyed upon by bobcats, other birds, snakes and such. House cats are replacing these apex predators in suburban environments.
Interestingly, I worked for (landscaping) almost 40 years in a neighborhood in Irvine,CA. Many people had outdoor cats and there did not seem to be a noticable deficit of birds (though that's a guess). In the early 90s coyotes moved in and starting on preying cats so everybody brought their pets indoors. The rabbit and rat populations subsequently exploded! I would see hundreds of rabbits mowing down people's lawns in the morning drive to the site. Residents could not grow veggies or fruit because rats would eat them ( A pair of bobcats did take up residence for awhile and controlled the problem but they were killed by rat poison put out by folks). Interestingly the coyotes could never control the varmint problem--in direct opposition to local environmentalist theory.
Anyway, you would think with this dearth of outdoor cats the bird populations would flourish...not so! It is just a relatively barren avian ecosystem with the usual suburban denizen-- lots of crows,a few pigeons, mockingbirds, and a few finches. Why is this? It's probably because the crows and rats are eating nestlings and eggs of more diverse species!
A fair point for the US but I can tell you from travelling in other countries that stray cats (and dogs) pretty much overrun many towns across the world.
Indeed there can certainly be too much of anything. Our former neighborhood in Fort Worth, TX had a lot of outside cats plus a high feral population. We still had Jays and Martins nesting in our trees so apparently the elevated habitat was protecting them but I imagine the pressure on avian population was high.
To be thorough, humans directly slaughter orders of magnitudes more birds each year. Completely understandable that Hannah doesn't discuss the factory farming of chickens and turkeys, as she has her lane where she's making such a big difference. But the brutality of today's chicken factory farms and industrial slaughterhouses absolutely dwarfs everything else in the developed world.
Offshore wind *can* be problematic in the wrong location, if migration routes and frequent feeding routes aren't considered. In the UK at least, it's not possible to get an operational license without at least 2 years worth of bird studies.
Offshore there is less benefit to higher towers, so the swept area is lower to the sea (the buffer zone is lower) meaning the risk can be higher to birds like gannets. Also...offshore death stats will be more challenging as there are many fewer carcasses to count!
Another idea would be to establish an environmental ceiling on how many birds a given turbine can kill. Once the number is exceeded, the turbine stops for a designated time...even at the expense of the operator and/or consumer.
I'm reminded of how the US Department of Agriculture has been actively trying to kill birds to protect sunflower crops for decades...
...populations kept rebounding. They continue to search for ways to limit their damage. But bats don't breed as quickly as say Blackbirds, so rebounds are difficult if not impossible.
On solutions, I know it antithetical for mainstream economists to call for limits that may 'eat into profits', but at some point isn't profit of capital over profit of life a bit anti-ethical?
This was very interesting, but I was confused by two sections. First, in your table of estimates, one column is "deaths per GWh per year", which I can't get my head round. That implies deaths would scale with power, not with energy production. Surely if you run a turbine for 2x as long, producing twice as much energy (but at the same power output), it'll kill 2x as many birds, not the same amount (all else equal)? Further discussions all seem to be in deaths per unit energy, not power, so is this just a typo-type error?
Second, when discussing the breakdown of deaths attributed to fossil fuels, the breakdown is by GWh, but surely this must mean by *deaths per* GWh?
Given the rapid increase in size, there are some issues with scaling up "birds strikes per turbine", to the total TWH produced in the US.
As you show later, smaller turbines have more strikes per turbine, but a large proportion of the annual energy produced will come from the bigger turbines, albeit many fewer of them. I'm not sure if this would increase, or decrease the overall number - but the trends are very clear, smaller, older turbines are getting to the ends of their economic lives and being replaced by much larger modern turbines. (admittedly this is all a bit academic as the message is the same - it's not exactly worth worrying about, we could just cull 10% of cats and that would have a much bigger impact - just don't tell my cat that!)
Also, for bats, there are detection systems that can scan the area in front of the turbine and shut down if significant bats are in the area, it doesn't usually harm production much as it's lower wind periods in the dawn and dusk (maybe 2 hours a day if I remember correctly).
I think this is the original paper you're referring to but likely paywalled for most, I have read it. Seems relevant as it is population level study with before and after data and compares to another human disturbance in fracking and shale wells.
Many of the earlier studies suggest population level with before and after studies are required and suggest there should be detectable influence on bird numbers and diversity.
This study finds otherwise with no detectable effect from wind farms, but also does find such a change for fracking and shale wells.
I actually think it is OK despite some limitations as rather than just looking specifically for a mortality effect at wind farms it uses three independent data sets to look for any effects overall over time.
I'm sure there's a lot of missed bird mortality elsewhere than wind farms but actually no-one even bothers looking for it or at it usually.
Quantifying the Effects of Energy Infrastructure on Bird Populations and Biodiversity
Please correct me if I am wrong, but I beleive your message about wind farms killing birds only relates to Horizontal Axis Wind Turbines (HAWT) not Veritical (VAWT). I personally do not believe that HAWTs is the Wind Farm of the future, VAWTs make much more sense and one reason is that far less birds are filled by them, if almost any.
If you really want to complete this bird killing discussion....you should look into VAWTs.
And there are other reasons why those HUGE HAWTs are just the result of lazy engineers and scientists, who did not look into VAWTS long enough to make a education choice - of of which is the waste they are producing from HAWTs that fall apart, explode, etc.
You might want to check the tables/charts I put in my first post on the subject of VAWTs.
VAWT vs HAWT is 100% not about "lazy engineers". There may be some advantages to VAWT offshore, but the construction, operations and maintenance of them pose significant challenges that, to date, have totally outweighed any of the benefits. And for birds, offshore, due to the blades on VAWTs coming much lower I suspect bird issues could be higher (not my area of expertise).
The Sovacool bird study is so non-scientific and nonsensical that it is so not cool, and should be denounced more strongly.
He assumes a large percentage of bird species will go extinct because of warming, for which there is no evidence of, and then extrapolates that if X% of species go extinct then that same number of birds will die. There are 50 billion birds on earth and more than 10% are sparrows, starlings, gulls and swallows. If the ivory-billed woodpecker becomes extinct (0-10 individuals currently suspected to exist) it won’t have a noticeable effect on the total bird population. Any species threatened with extinction necessarily has few individuals, white rhinos going extinct would be a loss, but won’t change the number of large mammals in Africa. His nuclear study is even worse as the rebuttal you linked to states (a barely operating mine in Colorado once had a kerosene spill which killed 40 Canadian Geese (a much disliked bird) in a one-time accident and he extrapolated that to be per kilogram of uranium produced over all years at all locations as though it was caused by the actual amount of uranium mined.
By giving any respect to these kind of ridiculous and biases studies does not increase my confidence in any other statistics you state, and I don’t want anyone to question he quality of ourworldindata statistics, which are too important to tarnish with bad data.
Thank you for putting this problem in context, Hannah. It's often very difficult to see the counterfactual of what a technology would replace (both good and bad), so looking at the numbers here for wind power was helpful for me.
They cost more to run than use. Cost more to the land owner than anyone. No easy way to recycle them. They are a criminal enterprise sell out to the UN Elite
I would add they are enterprise of treason. Accepting bribes from the UN and the Elite for their green agenda is giving away your country. Treason sell out they are. The purpose is to move humans off the lamd into density. Nothing more nothing less.
One thing not factored into the cat numbers is how many birds would be killed in a non-suburban, non-house cat habitat anyway. That is, birds are preyed upon by bobcats, other birds, snakes and such. House cats are replacing these apex predators in suburban environments.
Interestingly, I worked for (landscaping) almost 40 years in a neighborhood in Irvine,CA. Many people had outdoor cats and there did not seem to be a noticable deficit of birds (though that's a guess). In the early 90s coyotes moved in and starting on preying cats so everybody brought their pets indoors. The rabbit and rat populations subsequently exploded! I would see hundreds of rabbits mowing down people's lawns in the morning drive to the site. Residents could not grow veggies or fruit because rats would eat them ( A pair of bobcats did take up residence for awhile and controlled the problem but they were killed by rat poison put out by folks). Interestingly the coyotes could never control the varmint problem--in direct opposition to local environmentalist theory.
Anyway, you would think with this dearth of outdoor cats the bird populations would flourish...not so! It is just a relatively barren avian ecosystem with the usual suburban denizen-- lots of crows,a few pigeons, mockingbirds, and a few finches. Why is this? It's probably because the crows and rats are eating nestlings and eggs of more diverse species!
A fair point for the US but I can tell you from travelling in other countries that stray cats (and dogs) pretty much overrun many towns across the world.
Indeed there can certainly be too much of anything. Our former neighborhood in Fort Worth, TX had a lot of outside cats plus a high feral population. We still had Jays and Martins nesting in our trees so apparently the elevated habitat was protecting them but I imagine the pressure on avian population was high.
Great article 👏 Thanks.
To be thorough, humans directly slaughter orders of magnitudes more birds each year. Completely understandable that Hannah doesn't discuss the factory farming of chickens and turkeys, as she has her lane where she's making such a big difference. But the brutality of today's chicken factory farms and industrial slaughterhouses absolutely dwarfs everything else in the developed world.
This is not, BTW, a "Go Vegan!!!" comment. Just noting that in suffering per plate, chicken is the worst choice. https://www.onestepforanimals.org/about.html
I think it would be helpful to have a conclusion about whether wind farms are net positive for birds and bats compared to alternatives.
There are also some studies - to be treated carefully, as they are produced by turbine manufacturers - that suggest that offshore wind is not a major problem for birds. For example: https://group.vattenfall.com/press-and-media/newsroom/2023/unique-study-birds-avoid-wind-turbine-blades
An early study with input from the RSPB, Natural England and UK government: https://www.carbontrust.com/news-and-insights/news/pioneering-study-finds-seabirds-avoid-offshore-wind-turbines-much-more-than-previously-predicted?utm_source=dlvr.it&utm_medium=twitter
Offshore wind *can* be problematic in the wrong location, if migration routes and frequent feeding routes aren't considered. In the UK at least, it's not possible to get an operational license without at least 2 years worth of bird studies.
Offshore there is less benefit to higher towers, so the swept area is lower to the sea (the buffer zone is lower) meaning the risk can be higher to birds like gannets. Also...offshore death stats will be more challenging as there are many fewer carcasses to count!
Another idea would be to establish an environmental ceiling on how many birds a given turbine can kill. Once the number is exceeded, the turbine stops for a designated time...even at the expense of the operator and/or consumer.
I'm reminded of how the US Department of Agriculture has been actively trying to kill birds to protect sunflower crops for decades...
https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1154&context=icwdm_wdmconfproc
...populations kept rebounding. They continue to search for ways to limit their damage. But bats don't breed as quickly as say Blackbirds, so rebounds are difficult if not impossible.
On solutions, I know it antithetical for mainstream economists to call for limits that may 'eat into profits', but at some point isn't profit of capital over profit of life a bit anti-ethical?
This was very interesting, but I was confused by two sections. First, in your table of estimates, one column is "deaths per GWh per year", which I can't get my head round. That implies deaths would scale with power, not with energy production. Surely if you run a turbine for 2x as long, producing twice as much energy (but at the same power output), it'll kill 2x as many birds, not the same amount (all else equal)? Further discussions all seem to be in deaths per unit energy, not power, so is this just a typo-type error?
Second, when discussing the breakdown of deaths attributed to fossil fuels, the breakdown is by GWh, but surely this must mean by *deaths per* GWh?
Hannah, interesting article.
Given the rapid increase in size, there are some issues with scaling up "birds strikes per turbine", to the total TWH produced in the US.
As you show later, smaller turbines have more strikes per turbine, but a large proportion of the annual energy produced will come from the bigger turbines, albeit many fewer of them. I'm not sure if this would increase, or decrease the overall number - but the trends are very clear, smaller, older turbines are getting to the ends of their economic lives and being replaced by much larger modern turbines. (admittedly this is all a bit academic as the message is the same - it's not exactly worth worrying about, we could just cull 10% of cats and that would have a much bigger impact - just don't tell my cat that!)
Also, for bats, there are detection systems that can scan the area in front of the turbine and shut down if significant bats are in the area, it doesn't usually harm production much as it's lower wind periods in the dawn and dusk (maybe 2 hours a day if I remember correctly).
This may be relevant:-
https://pubs.acs.org/doi/suppl/10.1021/acs.est.3c03899/suppl_file/es3c03899_si_001.pdf
I think this is the original paper you're referring to but likely paywalled for most, I have read it. Seems relevant as it is population level study with before and after data and compares to another human disturbance in fracking and shale wells.
Many of the earlier studies suggest population level with before and after studies are required and suggest there should be detectable influence on bird numbers and diversity.
This study finds otherwise with no detectable effect from wind farms, but also does find such a change for fracking and shale wells.
I actually think it is OK despite some limitations as rather than just looking specifically for a mortality effect at wind farms it uses three independent data sets to look for any effects overall over time.
I'm sure there's a lot of missed bird mortality elsewhere than wind farms but actually no-one even bothers looking for it or at it usually.
Quantifying the Effects of Energy Infrastructure on Bird Populations and Biodiversity
https://doi.org/10.1021/acs.est.3c03899
Yes Thanks. I was trying to find a way to link a public access version.
That supporting info shows the data pretty well I think anyway, just a bit less background information and discussion
Dear Hannah,
Please correct me if I am wrong, but I beleive your message about wind farms killing birds only relates to Horizontal Axis Wind Turbines (HAWT) not Veritical (VAWT). I personally do not believe that HAWTs is the Wind Farm of the future, VAWTs make much more sense and one reason is that far less birds are filled by them, if almost any.
If you really want to complete this bird killing discussion....you should look into VAWTs.
And there are other reasons why those HUGE HAWTs are just the result of lazy engineers and scientists, who did not look into VAWTS long enough to make a education choice - of of which is the waste they are producing from HAWTs that fall apart, explode, etc.
You might want to check the tables/charts I put in my first post on the subject of VAWTs.
https://wasterush.info/vawt/
May I use some of your information in my next VAWT post?
Wholeheartedly,
Lesley
Wishing to encourage Everyone to find the Value in their Waste.
https://wasterush.info/ fossil fuel is ancient Waste. We can do better with today's Waste.
VAWT vs HAWT is 100% not about "lazy engineers". There may be some advantages to VAWT offshore, but the construction, operations and maintenance of them pose significant challenges that, to date, have totally outweighed any of the benefits. And for birds, offshore, due to the blades on VAWTs coming much lower I suspect bird issues could be higher (not my area of expertise).
You appear to have an agenda here.
great article, super balanced approach to the issue. I love how you interrogated every assumption.
The Sovacool bird study is so non-scientific and nonsensical that it is so not cool, and should be denounced more strongly.
He assumes a large percentage of bird species will go extinct because of warming, for which there is no evidence of, and then extrapolates that if X% of species go extinct then that same number of birds will die. There are 50 billion birds on earth and more than 10% are sparrows, starlings, gulls and swallows. If the ivory-billed woodpecker becomes extinct (0-10 individuals currently suspected to exist) it won’t have a noticeable effect on the total bird population. Any species threatened with extinction necessarily has few individuals, white rhinos going extinct would be a loss, but won’t change the number of large mammals in Africa. His nuclear study is even worse as the rebuttal you linked to states (a barely operating mine in Colorado once had a kerosene spill which killed 40 Canadian Geese (a much disliked bird) in a one-time accident and he extrapolated that to be per kilogram of uranium produced over all years at all locations as though it was caused by the actual amount of uranium mined.
By giving any respect to these kind of ridiculous and biases studies does not increase my confidence in any other statistics you state, and I don’t want anyone to question he quality of ourworldindata statistics, which are too important to tarnish with bad data.
Thank you for putting this problem in context, Hannah. It's often very difficult to see the counterfactual of what a technology would replace (both good and bad), so looking at the numbers here for wind power was helpful for me.
Oh God. Nit this again. Cats kill about 2 billions birds a year. In North America alone!
How many eagles, hawks, falcons and condors are killed by house cats?
How many bunnies, mice, and lizards are caught by swallows and doves?
They cost more to run than use. Cost more to the land owner than anyone. No easy way to recycle them. They are a criminal enterprise sell out to the UN Elite
I would add they are enterprise of treason. Accepting bribes from the UN and the Elite for their green agenda is giving away your country. Treason sell out they are. The purpose is to move humans off the lamd into density. Nothing more nothing less.
Having commented earlier, it is encouraging to see that the wind industry can behave responsibly. Another point of differentiation from the fossil fuel sector. This in today's news (Denmark cancels planned offshore wind project as area is redesignated as a bird sanctuary). https://reneweconomy.com.au/danish-offshore-wind-project-cancelled-after-area-redignated-as-bird-sanctuary/
thank you so much for your careful and considered work on these issues Hannah; fascinating and important in equal measure! _/\_