
Investigating the scale of bird deaths caused by wind turbines
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Charlotte MacDonald
Hello and thanks for downloading the More or less podcast. We're the program that looks at the numbers in the news and in life and in the sky. I'm Charlotte MacDonald. If there's one thing Donald Trump definitely doesn't like, it's wind turbines, or windmills, as he calls them.
Donald Trump
You know the windmills, boom, boom, boom. They kill so many birds. You look underneath some of those windmills. It's like a killing field of birds.
Charlotte MacDonald
It's been suggested that Trump's dislike of windmills goes back to a golfing dispute. In the early 2000 and tens, a brave soul proposed building a wind farm off the coast of a golf course he owns in Scotland. Trump fought back, labeling the wind turbines monsters and even testifying against the plan to the Scottish Parliament. But it's the cost to bird life that now seems his main concern.
Donald Trump
But I've restricted windmills in the United States because they also kill all your birds. You know, they wipe out. You know, it's interesting if you shoot a bald eagle in the United States, they put you in jail for five years. And yet windmills knock out hundreds of them. They don't do anything. You know, the thing makes it so. And of course, it's like a graveyard for birds. If you love birds, you'd never want to walk under a windmill because it's a very sad, sad sight. It's like a cemetery. We put a little. We put a little statue for the poor birds.
Charlotte MacDonald
Earlier this year, he posted on Truth Social claiming wind turbines were killing birds by the millions. But is he right? Do wind turbines kill millions of birds a year?
Dr. Hannah Ritchie
It's not completely wrong. I think with this statement, the S on the millions is probably doing some heavy lifting.
Charlotte MacDonald
This is Dr. Hannah Ritchie, Deputy editor at Our World in Data and senior researcher at the University of Oxford.
Dr. Hannah Ritchie
I think my best estimate is that in the US wind turbines probably kill between 1 and 2 million birds every year. So with the million statement, that's broadly right, but I think it's missing a lot of context.
Charlotte MacDonald
Okay, let's get into the details of this number, and let's start with the basics. We're going to focus on the United States because that's what Trump's comments were referring to, and it's where we have reasonable data. How do we count how many birds are killed by wind turbines each year? It turns out those bird cemeteries Trump was talking about aren't far from the truth.
Dr. Hannah Ritchie
Yeah, so figuring this number is very difficult. I mean, there's no big national database where we store all of the different birds killed by wood turbines every year. It's often extrapolated from these smaller scale studies. So what researchers will do is that they. They'll go out to a wind farm and they'll basically count the number of bird carcasses that they find.
Charlotte MacDonald
Sounds like a fun way to spend your weekend. It's important to note that these studies only measure the birds killed by onshore wind farms. It's much harder to measure birds killed by wind turbines in the ocean, and the data on that isn't reliable anyway. You can use the data from counting dead birds to calculate a rate of deaths per wind turbine. Hannah found all the studies she could that did this to see if they agree. They did not.
Dr. Hannah Ritchie
So most of the studies I looked at were in the range of 4 to 18 birds killed per wind turbine per year. So that's a fourfold difference. So the difference there is large.
Charlotte MacDonald
The problem is that dead birds are hard to count. Sometimes small birds get missed. Sometimes wild animals eat Dead birds before they're counted. The number and type of dead birds also varies depending on the location.
Dr. Hannah Ritchie
Some particular species, such as eagles, raptors, shore like birds, they tend to be at higher risk. And that's for a couple of reasons. The main one being that they will often use kind of ridge tops to get lift when they're flying. And that's obviously a very, very good spot to put a wind turbine. It's very windy there. You'll also get migratory birds that will go through the same spot over and over through migration patterns, and they also tend to be at higher risk.
Charlotte MacDonald
To account for the bird count problems, scientists try to model the number of birds that might die but not be counted. Hence the big range of answers.
Dr. Hannah Ritchie
So if we take the range of figures for the number of birds killed per turbine per year in the U.S. so 4 to 18, we multiply that by the number of turbines in the U.S. we get this estimate between 300,000 and about 1.3 million birds killed across the U.S. every year.
Charlotte MacDonald
Hannah thinks that because there's a risk of underreporting in the dead bird count, the higher numbers are more likely to be in the right ballpark.
Dr. Hannah Ritchie
So naturally, picking the higher number is maybe more honest and adjusts for that.
Charlotte MacDonald
So Hannah reckons a figure of maybe 1 to 2 million birds being killed every year looks justifiable. President Trump is roughly right. As long as you think millions means 2 million and not 100 million. But as so often on this program, the numbers don't tell the whole story.
Dr. Hannah Ritchie
Yeah. So my estimate is that wind turbines probably kill between 1 to 2 million birds every year in the U.S. but to put that in context of other hazards, kind of top of the list is cats. Now, cats probably kill just over 2 billion. Right. So 1,000 times higher than my estimates for wind turbines. Those figures come with a lot of uncertainty. They're not precise in any way. I tried to figure out how many birds do they kill per cat, and it works out around 20 per year for a kind of feral outdoor cat. Now, that probably seems reasonable to me.
Charlotte MacDonald
And it's not just cats that are more deadly for birds than wind turbines.
Dr. Hannah Ritchie
Buildings and cars and trucks are also very high on that list. So they kill maybe 600 million for buildings and around 200 million for cars and trucks. There are other big hazards like pesticides, communication towers. They are kind of in the order of magnitude of millions to tens of millions. And obviously, these hazards just don't get the same attention in terms of policy and media attention as wind turbines do. So I think the number is maybe correct, but I think the context surrounding it is missing to help us understand whether there should be a barrier to us deploying wind power or not.
Charlotte MacDonald
One thing that's definitely not true is that wind turbines are killing all the birds. The back of an envelope calculation is even harder for the total US bird population. But Hannah had a look at the data to try and give us a rough idea.
Dr. Hannah Ritchie
Some of the best estimates I've seen have been in the range of maybe 10 to 20 billion. So when you're think about the threat from wind turbines, you're Talking about maybe 1 million relative to 10 to 20 billion birds in total. So as a share of the total bird population, the threat is reasonably small.
Charlotte MacDonald
Birds also often reproduce pretty fast and have quite short lifespans. So there's a lot going on in this number. So what's the final verdict? Should the number of birds being killed make us reconsider our use of wind turbines?
Dr. Hannah Ritchie
I don't think the death toll from wind turbines should stop us from deploying wind power for a couple of reasons. I think the first one is that we are actually deploying clean energy for a reason. And part of that reason is to mitigate climate change and also it has the side benefit of mitigation air pollution. And both of those are relatively large threats to birds and wildlife at large. So there is some downsides in terms of bird loss to wind turbines. But on the flip side, the problem we're trying to solve also has downsides for, for this wildlife. I think what it does mean though, and I think this comes back to the types of birds that are most at risk, is that I think we also need to think carefully about where we're putting wind turbines and what we're putting in place to try to mitigate those risks. I don't think this is purely about total numbers. I think there are genuine risks to specific and often rarer species. And I think we do need to take that selection quite carefully.
Charlotte MacDonald
Thanks to Hannah Ritchie, Deputy editor at Our World in Data and senior researcher at the University of Oxford. If you've seen a number or another bird related hazard you think we should look at email more or lessbc.co.uk until next week. Goodbye.
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Episode: "Is Trump right that wind turbines are killing millions of birds?"
Host: Charlotte MacDonald (BBC Radio 4)
Guest: Dr. Hannah Ritchie (Our World in Data, University of Oxford)
Date: April 18, 2026
This episode fact-checks Donald Trump’s repeated claim that wind turbines (windmills) are “killing birds by the millions” each year in the United States. Presenter Charlotte MacDonald investigates the truth behind the numbers, consults expert Dr. Hannah Ritchie, and places the death toll from wind turbines in the broader context of bird hazards in the US.
“You know the windmills, boom, boom, boom. They kill so many birds. You look underneath some of those windmills. It’s like a killing field of birds.” – Donald Trump (02:01)
“It’s like a cemetery. We put a little statue for the poor birds.” (02:39)
Expert Analysis: Dr. Hannah Ritchie concedes there is some truth:
“It’s not completely wrong. I think with this statement, the S on the millions is probably doing some heavy lifting.” – Dr. Hannah Ritchie (03:31)
Explaining the Numbers:
Counting Challenges:
Statistical Range:
“If we take the range... 4 to 18 birds killed per wind turbine per year... we get this estimate between 300,000 and about 1.3 million birds killed across the U.S. every year.” – Dr. Hannah Ritchie (06:14)
Contextualizing the Number:
“But as so often on this program, the numbers don't tell the whole story.” – Charlotte MacDonald (06:49)
What kills more birds than turbines?
Dr. Ritchie notes:
“These hazards just don't get the same attention in terms of policy and media attention as wind turbines do.” (07:53)
“So as a share of the total bird population, the threat is reasonably small.” – Dr. Hannah Ritchie (08:46)
“I don't think the death toll from wind turbines should stop us from deploying wind power... We are actually deploying clean energy for a reason... to mitigate climate change... mitigation of air pollution. Both of those are relatively large threats to birds and wildlife at large.” (09:21)
“I think we also need to think carefully about where we're putting wind turbines and what we're putting in place to try to mitigate those risks.” (09:21)
On the S in “Millions”:
“The S on the millions is probably doing some heavy lifting.” – Dr. Hannah Ritchie (03:31)
On Cats as Bird Killers:
“Cats probably kill just over 2 billion [birds]. Right. So 1,000 times higher than my estimates for wind turbines.” – Dr. Hannah Ritchie (07:12)
Perspective on Population:
“When you think about the threat from wind turbines, you’re talking about maybe 1 million relative to 10 to 20 billion birds in total.” – Dr. Hannah Ritchie (08:46)
Policy Implication:
“I don’t think this is purely about total numbers. I think there are genuine risks to specific and often rarer species. And I think we do need to take that selection quite carefully.” – Dr. Hannah Ritchie (09:50)
Conclusion:
Trump's claim isn't exactly wrong—wind turbines do kill around a million or two birds per year in the US, but this is negligible compared to other hazards and the total bird population. The real risk lies in specific exposed or rare species, emphasizing the importance of careful wind farm placement, not halting wind energy development. The episode provides data-driven analysis, debunking both exaggeration and dismissal.