26
votes
Black paint on wind turbines sharply reduces bird death but there are issues
Link information
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- Title
- Could Black Paint Protect Birds from Wind Turbines?
- Published
- May 28 2025
- Word count
- 588 words
I wonder if other colors can be just as effective. The article mentions this study in South Africa where they're using "signal red" instead of black, and the included photo also has it use stripes rather than paint the entire blade. It mentions some manufacturers also already paint turbines with red tips due to civilian air safety requirements.
That article also goes into how the weight of the paint can have an effect, and explains more of the technical details and challenges with implementing it.
I'm surprised no one has built a drone for this yet. Seems like the perfect task.
The Drone Bird Company does more or less what you're describing I think
I'm guessing the windy conditions are the limiting factor, since strong winds can easily push them around and they'd need to remain in place while applying paint to specific areas.
I remember a doing a module during my Physics degree many years ago about biomimicry; one of the things mentioned was integrating reflective UV stripes onto skyscraper glass, because spider webs also reflect UV and birds can see/avoid it. Some studies had shown that this glass did significantly reduce bird collisions.
Obviously there's a big difference between static glass and rotating turbine blades, but I wonder if there are ongoing tests using a similar principle.
I've gone down a rabbit hole on the claim that "wind turbines kill a lot of birds" and honestly, after researching as much as I could, I think its mostly fabricated. If you look at multiple sites they all make the same claim - high estimates of millions killed - but no one seems to have any proof. This is typical in the studies: "We systematically derived an estimate of bird mortality for U.S. monopole turbines by applying inclusion criteria to compiled studies, identifying correlates of mortality, and utilizing a predictive model to estimate mortality along with uncertainty." So the studies looked at other estimated studies and made up their own estimates? Is that hard science? What happened to direct observation? Video monitoring? Thermal image tracking cameras at a fixed site?
The MOST I could find was a few pics that showed a few birds laying at the base of a turbine and even those, the photographer admitted he collected the birds from around the area and grouped them together to emphasize the shot. I believe this is the shot that's most used: https://climatechangedispatch.com/the-sinister-truth-about-bird-killing-wind-farms/
IF turbines were killing a lot of birds, somebody somewhere would have video or photographic proof of it. Or a study that shows how bird deaths were monitored and there were dozens or hundreds killed. It doesnt seem to exist. And without obvious proof, I am skeptical of the estimates.
While the "millions of birds" number absolutely feels like an exaggeration to try to get people more worked up about it (in the same vein of PETA exaggerating animal abuse allegations), I don't think that means the problem is nonexistent.
Honestly I think the bigger concern for ecologists isn't the number, but the fact that of the birds that DO die, there are many endangered species. A single death can have a BIG impact on that species' chance of long-term survival/recovery, as it cuts down the possibility for at least one mating pair and can potentially orphan chicks or eggs leading to their deaths.
Literally, the first point of this article says:
So this problem's relevance is based on a very case-by-case basis. In that vein, that also is probably why there have been limited studies. The significance and impact will vary for each location, so you can't just use the numbers counted from one or even five locations to estimate a global average or impact. One farm may have 100 fairly common birds a year get killed, but another could have 6 deaths belonging to a critically endangered species with a population under than 250. Those are two very different impacts.
Reminds me of the Bearded Vulture in the Netherlands. The species is at risk and I think only a handful exist here.
One of them decided to headbutt a train and the bird obviously folded like paper and became news. It wasn't the fact that birds hit trains, it's that this specific bird's death is significant enough to impact the species.
If we can somewhat cheaply prevent another endangered bird from hitting a turbine it's a good thing.
Agreed that it's a problem worth thinking about and quantifying, but it needs to be compared against the relative harm of spinning up an equivalent amount of non-wind energy to make a decision one way or another. I suppose the alternative is requiring less energy as a society, but that doesn't seem like it'll be happening any time soon.
I'll have to see if I have time for my own rabbit hole.
Do you have a similar question about glass skyscrapers on migration routes? How broad is your claim?
No I would believe a claim about skyscrapers killing millions much more readily than turbines. On our own acreage we have birds killing or at least stunning themselves so regularly that we put tape on the two most often hit windows to keep more from hurting themselves. Window injuries on a large building make sense to me. A big narrow blade that takes a great deal of precision and bad luck to hit just doesn't.
What percentage of the time is the blade passing through the relevant range? If it's in any given section of its range 3% of the time (making up that number, to be clear) wouldn't it make sense that it'd kill 3% as many birds as a building of the same size, times the number of windmills in the farm?
I dunno about that. Google says a typical turbine has a crossection width of 10 ft which thins down to a couple of feet at the tip, so maybe it averages 6 ft? But its constantly moving so the bird has to not only be hitting that 6 ft blade but at the perfect time. A half second early or late and it probably gets a rude bit of turbulence.
As opposed to a skyscraper with reflective glass. The birds are attracted to their own image, mistaking it for other birds, or think they can fly right through. My very unscientific analysis.
I'd say the movement actually makes it a bit easier to hit, since it means more potential places where they'd crash into a blade rather than just three stationary positions. I'm just thinking of trying to throw something between the blades of a fan, much easier when you don't have to time it. I'm pretty sure wind turbines spin slower than fans, but the principle seems similar enough to me.
I'm not an engineer or a mathematician, but I think the function to determine that probability should include the speed of the blade and its size and also the speed of the bird and its size. A goose or a stork or a swan should be at more risk than a swallow or a finch.
Well now you also have to consider the height at which different birds fly, and the location of the turbines in which birds are relebant. Here they're mostly placed in cornfields and the birds at risk would be red-tailed hawks, blackbirds, crows, specific migratory fowl and local songbirds, etc. vs by or off the coast where seabirds may be the most at risk.
More math
What it if was an African Swallow?
Is this a Monty Python reference?
Possibly. If your mother smells of elderberries.
Monty Python was hit and miss for me. All my friends were into them for a while.
I find its a whole lot funnier if you're extremely tired. But sometimes annoying too.
This doesn't really matter. If the blades weren't moving, then a bird which would have hit a moving blade would instead miss the stationary blade, and vise versa. (I mean, ignoring that birds would almost certainly avoid a large, opaque, stationary obstacle.) In fact, you get a bit of bonus "range" on the spinning blades because they can hit a bird which "missed" them from an instantaneous cross-sectional area perspective.