When a massive handwavium accident happened on Earth, 99.9% of all flight-capable birds worldwide, instead of dealing with it, answered with "Nope, gone to heaven."

Basically, they died instantly.

Birds that do not fly, like chickens, penguins, ostriches, and so on, are fine. Birds that were able to fly but weren't flying at the moment, not so much (not at all).

What are the worst-case scenario for this mass-extinction event? How screwed is the rest of the world, the surviving species, like, dunno, humans?

Assume an ordinary 2020's world, just like ours.

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    $\begingroup$ I think chickens can fly, just not very far. $\endgroup$ Mar 31 at 16:40
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    $\begingroup$ Dead are the birds which are flight capable as species or as individuals? There are many individual birds of flying kind which temporary or permanently are incapable to fly. $\endgroup$
    – Alexander
    Mar 31 at 17:16
  • $\begingroup$ @Alexander Does the answer to that question significantly change the answer to Mindwin's question? $\endgroup$ Apr 1 at 16:43
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    $\begingroup$ @Daniel Wagner Depends on what kind of answer is it :) If species can survive on individual level, there is a good change of repopulation, particularly for livestock and pet birds. If not, there will be lasting consequences. $\endgroup$
    – Alexander
    Apr 1 at 17:08
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    $\begingroup$ A good (nonfiction) book dealing with biodiversity and extinction is Half Earth by E.O. Wilson. From that book I agree with Daniel B's assessment that it would be apocalyptic. $\endgroup$
    – L.T.Smash
    Apr 1 at 21:24

5 Answers 5


Insects swarm, crops die, people starve, society collapses

The death of all birds would be apocalyptic in short order.

While John O's question covers a lot of aspects of birds' place in the ecosystem, it misses a very important one. Birds eat insects. A lot of insects. 400,000,000 tons of insects a year. For a sense of scale, that's more than the combined mass of all of humanity.

One of the causes of the Great Chinese Famine, which killed >10,000,000 people, was the systematic and misguided extermination of sparrows, which resulted in massive spikes in insect populations.

Removing the world's bird population will turn every habitable area into something like this:

enter image description here

At which point they will very rapidly become non-habitable.

Wheat, rice, potatoes, corn, soybeans, all will become food for the endless swarming pests. Everything that grows will be eaten, down to the last shred of grass. Cattle and wild animals alike will starve for lack of feed. The world will slowly but inexorably starve.

You might have a few holdouts survive on preserved food for a few years, but since agriculture will be impossible, eventually, they will likely starve as well.

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    $\begingroup$ Insects are not birds, and OP specified birds. There is nothing implausible about "we would all starve" here, @Goodies. The stability and security of the West is an illusion. Take away our agriculture, and that civilization will crumble within one missed harvest cycle and disintegrate after two. $\endgroup$
    – Daniel B
    Mar 31 at 20:12
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    $\begingroup$ @Goodies Humans won't adjust because we won't have food. We need crops to survive, and bugs eat crops. The degree to which 'humans destabilize the biome' relative to an instantaneous extinction of all bird species is literally two orders of magnitude smaller. Over the last 500 years, humanity has driven ~150 species of birds to extinction. Here, we'd be rendering 10,000 species extinct in a second. $\endgroup$
    – Daniel B
    Mar 31 at 23:53
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    $\begingroup$ @DanielB The biosphere won't completely collapse. There are plenty of things that eat insects which will do just fine, for example. It'll be a mass extinction event sure, but enough varieties of things will survive that the world will evolve its way to a new normal, such that you wouldn't be able to tell it had happened in a few million years. That "new normal" will of course take long enough to emerge that it's not relevant on a human timescale. But we're not talking about humans suddenly stranded on a lifeless rock, either. There's biomass they can eat (like insects!). $\endgroup$
    – Ben
    Apr 1 at 0:03
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    $\begingroup$ I don't think it will be that bad, medium term - we would still have animals to eat (insects won't eradicate grass) as well as everything from sea. Obviously, that society collapses and a lot of people die are pretty much given - one year you get a lot of insects that eradicate vegetables, the next year insects are dead by no food left, the next decade ecosystem finds a new equilibrium with fewer species (and specimens) left. $\endgroup$ Apr 1 at 12:02
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    $\begingroup$ Can humans not eat insects? $\endgroup$
    – Jafe
    Apr 1 at 13:22

You do get to tell us how your premise works, of course... but chickens fly just fine. Modern breeds are heavier (more meat), and being heavy they have trouble with sustained flight. They'll never fly 5000 miles south for winter, but to get to a low roost above where predators will get them is pretty doable for all but the heaviest.

Turkeys, too. Ducks. Geese. Most of the fowl that we eat, all of them gone.

Thus, no more chicken tendies... for anyone.

If that weren't bad enough, we have some birds who are competent pollinators of exotic plants. Hummingbirds mostly, but others as well. Some of those plant species are already endangered, so you're looking at a minor extinction event beyond just the birds themselves.

Other ecosystems rely on birds for food... reptiles a bit. Those populations if already endangered, could easily be pushed over the edge. Snakes, lizards, alligators and crocodiles maybe.

The good news is that this isn't without its benefits. So-called "bird flu" will be a thing of the past. The flu, as you all are no doubt aware, is a virus that likes to jump species. In particular, it will favor pigs and birds as well as ourselves... and birds being highly mobile are very good vectors. It's not as if one farmer's pigs are visiting the other farmer's pigs 10 miles down the road late at night. But birds will easily cover that distance in minutes, and may do so every day. They'll poop in the pig pens, pick it over for food, and then move on to the next. And then go poop on your car door handle. (Feces aren't a particularly viable mechanism, just one chosen to illustrate things in general.)

With those birds gone, it's quite possible that the flu will become less adaptive and widespread. It's possible flu epidemics would become a thing of the past entirely (though there's little hope for it becoming extinct itself).

Longer term though, there are other problems. Some of the richest phosphate deposits are from birds (bird poop again, I keep circling back to it). These things take tens of thousands of years to develop, but when ocean birds nest on certain islands generation after generation, their feeding on fish but pooping on shore in places where it doesn't wash away quickly tends to concentrate good old phosphorous there. That will cease. This won't become a problem for a long time, if ever, but it does demonstrate how many cycles and systems are being affected by their absence.

Similarly, birds have alot to do with how new islands are colonized at sea. Some seeds and animals can be washed ashore aboard detritus, but birds tend to carry alot with them as well. And not just islands, new lakes may actually be seeded by birds, who carry fish eggs with them in their guts, or snails on their feet.

If evolution ever replaces birds with something else (it's not guaranteed, some niches are difficult to learn to exploit), it will be many millions of years before that organism takes over the skies again.

We aren't in any immediate danger of becoming extinct in this world, or even becoming involuntary vegetarians. But the loss of the turducken as the pinnacle of culinary art will be grieved for all eternity.

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    $\begingroup$ Good answer. Also true that bird poop creates phosphate, but for every crap they take on land they take 5 over the sea which basically fertilises the water around those islands even more. Fish and other animals eat it. Wipe out the birds and you lose a lot of fish. Bird poop is a huge part of the food chain around island nesting sites. $\endgroup$
    – Kilisi
    Apr 1 at 1:36
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    $\begingroup$ It seems that bats would quickly start moving into many of the niches now cleared by birds. Insects could also quickly adapt to filling some of the smaller slots. $\endgroup$
    – prosfilaes
    Apr 1 at 16:15
  • $\begingroup$ @prosfilaes Bat McNuggets? $\endgroup$
    – John O
    Apr 1 at 16:23
  • $\begingroup$ That's artificial selection, not natural. Humans will quickly breed something to fill any niches; I suspect rodent McNuggets, though lizard, frog or penguin might be possibilities. Guinea pig McNuggets are most reasonable; the rest would probably take significant breeding. $\endgroup$
    – prosfilaes
    Apr 1 at 16:42

We'll survive, but it's gonna take alot of lasers

Lasers have already been shown capable of being employed to take down mosquitoes. We'll just need to modify and scale this existing technology to handle the bugs of all the shapes and sizes normally eaten by birds that are now extinct. Note that we won't have to fight the bugs forever:

99.9% of all flight-capable birds worldwide [will be dead].

This still leaves 0.1% alive. Assuming 100 billion birds were alive before the disaster (I'm rounding to 100B for convenience), then 0.1% left makes 100M birds. Assuming birds grow at a rate of 2x/year, then in around 3 decades the avion population should return to origonal levels (2^30 = 1024). Correction: 1 decade (2^10=1,024; 100M•1024≈100B).

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    $\begingroup$ 2^30 is about a billion. You want 2^10 = 1024. $\endgroup$ Apr 1 at 16:46

(This answer assumes only flying bird species would be affected directly by this event, no other species!)

God hates dinosaurs ?

Another dinosaur disaster.. but some of the usual suspects will survive.. again..

Extinction events. Dino's have been there. One giant asteroid and a 20 years nuclear winter.. And they were already on the way out before that, for a few million years.. most of them cold-blooded and afraid of water. But some dinosaurs had managed to transform themselves into flying birds, or thrive in water. Only few dinosaurs remained unchanged, like crocodiles and ostriches.. Others developed not depending on flight, like chicken, penguins and partridges. These non-flying dinosaurs will survive this "handwavium event". But most of the other dinosaurs will just vanish again. Poor birds. 99.9%, This blow seems fatal. Is it, really ?

Some flying birds will survive, but loose their wings

According to the opening, flying birds would vanish. True for all predator birds and sea-thriving birds like seagulls: these really depend on flight every day and go extinct. But you'd get certain e.g. migratory birds, e.g. sparrows or geese individuals would survive the event. You'd have many jugs, that never flew. Some individuals will survive the event. Some were born with short wings, or non-functional wings. They don't fly, they try to survive on land, many would die in winter season - but they don't really depend on flight either. These birds can learn to live and thrive on land, in sunshine regions.

The main reasons birds need to fly: hunting, predators and season. Now suppose there's no predators used to chasing these surviving birds, and there is no relevant winter. The flight-incapacitated sparrow is in the right place; there is plenty of food. When the "hand-waved" event occurred, they were just lucky. This species will survive. It will copulate, lay eggs and their offspring will change the shape of their beak (see Darwin) and start to pick fruit and seeds all year.

Other species ?

What species would care.. Some plants depend on birds, to spread their seeds. But most birds are just seed-picking and mouse-eating anarchists, out of reach and not competing. Of course, mammal predators fancy a bird now and then, and everyone loves to eat doves, but prey-wise, there are few predator species that would especially suffer when birds vanish.

destabilized biome

Sure, the biome will be destabilized. With hordes of birds suddenly disappearing, their food will remain on the ground. Rodents could profit considerably; the real issue will be flying seed-eating insects like locusts, that were already mentioned in an earlier answer. They would cause havoc, but in time, locust swarms will disappear again, because the food gets exhausted. While the locusts roam around and procreate, other seed-eating species like hamsters and mice would suffer the consequences; many of these small mammal species could be overrun and get extinct.


Don't worry. Humans are a different league. They don't rely on evolution to adjust to changes - they have technology to compensate. Any biomass will do; humans can eat wood if needed. In the first years, the locust plague could cause ⅔ of the human population to die of hunger, but areas with high-tech means will adjust quickly. Humans won't go extinct easily.


Chickens will diversify to fill empty niches.

There are a lot of chickens. Chickens alone account for a substantial minority of all birds. In a fit of humility and passion these will be released to spread over the globe. Chickens will naturally fill the roles of their departed birdly brethren and sistren. In circumstances where chickens physiologically struggle to fill those roles, the world will react with understanding and accomodations.

I was thinking the penguin role might be the hardest but forgot penguins will be also be exempt from the great bird dying. Penguins can be imported from antartica to other places in the world where they will take over for ducks.

Also kakapos can come fill in for the goats if the goats have any trouble, or maybe stand ready as emergency goat backups.


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