# All humans vanish. How many other species die? **URL:** \ **Category:** Factual Questions\ **Created:** [March 25, 2015, 4:48am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924 "2015-03-25T04:48:17Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [March 25, 2015, 4:48am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924/1 "2015-03-25T04:48:17Z")
I See subject. Not necessarily on an evolutionary scale, although humans-as-stepped-on-butterfly is interesting too. I’m primarily thinking fauna; I suppose there are biota galore that exit when we do. I started thinking about this when looking at pugs, a dog which, apparently, cannot be born except by Caesarian. Although not a species, they are Unfit to Live. Then I progressed to thinking about the ecosystem of animals. II Are biota fauna? III “Ecology” is to “ecosystem” as “ethology” is to …? Can’t think of the word. ---
**Author:** ![Shagnasty](https://avatars.discourse-cdn.com/v4/letter/s/9dc877/32.png) [@Shagnasty](https://boards.straightdope.com/u/Shagnasty)\ **Post date:** [March 25, 2015, 5:10am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924/2 "2015-03-25T05:10:07Z")
My examples aren’t whole species either but they still represent potentially billions of individual animals. There are certain species that only exist in the number if not form that they do because they are symbiotic with human populations. They include dogs, rats, mice, squirrels, pigeons, many domestic cats and most farm animals among many others. The vast majority of domestic horses, cows, sheep and chickens cannot survive in large numbers on their own because they will be among the first to be hunted down by an explosion of top-level predators or face sickness and/or death through starvation. However, death to humans doesn’t mean that nature would be back in natural harmony in any reasonable amount of time. There are other species like domestic pigs that do extremely well in the wild because they are large, aggressive and will eat just about anything. Feral hog populations are an extremely serious ecological problem in the American Southeast and Texas in particular. Even with no hunting limits and kill on sight policies, it is still extremely difficult to keep them from destroying the habitat for many other species. It is hard to predict exactly what would happen if unchecked ecology were allowed to prevail but it wouldn’t be pretty for an extremely long time. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [March 25, 2015, 5:26am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924/3 "2015-03-25T05:26:32Z")
Well, I started out thinking exactly along those lines, with domesticated animals and the the limits of ferality. (Band name.) And I was thinking that cats will/can go on being cats, at least in the short run, and dogs dogs, just that if I were a pug I’d start worrying sooner. As for number and “form” of course–pure breeds depends on whose definition of purity. ---
**Author:** ![coremelt](https://avatars.discourse-cdn.com/v4/letter/c/4491bb/32.png) [@coremelt](https://boards.straightdope.com/u/coremelt)\ **Post date:** [March 25, 2015, 5:54am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924/4 "2015-03-25T05:54:14Z")
I don’t see why any species would go extinct, except for a very few that don’t currently exist in the wild and are only kept alive through captive breeding programmes. Dogs, cats, horses, chickens, pigs, sheep and goats all have existing feral populations in various parts of the world that would thrive without us. Lots of heavily domesticated breeds would die out, but their feral cousins who are the same species, would survive. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [March 25, 2015, 5:57am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924/5 "2015-03-25T05:57:05Z")
> [@Shagnasty](#): > > There are certain species that only exist in the number if not form that they do because they are symbiotic with human populations. They include dogs, rats, mice, squirrels, pigeons, many domestic cats and most farm animals among many others. The vast majority of domestic horses, cows, sheep and chickens cannot survive in large numbers on their own because they will be among the first to be hunted down by an explosion of top-level predators or face sickness and/or death through starvation. 😕 But none of these species is in the slightest danger of becoming extinct. Does the OP want examples of species that will become extinct, or examples of species where a lot of individuals will die even though the risk of extinction is nil? > [@](#): > > There are other species like domestic pigs that do extremely well in the wild because they are large, aggressive and will eat just about anything. Feral hog populations are an extremely serious ecological problem in the American Southeast and Texas in particular. Even with no hunting limits and kill on sight policies, it is still extremely difficult to keep them from destroying the habitat for many other species. That is all even more true of the species that you listed above that you seem to think are examples of near extinction. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [March 25, 2015, 6:04am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924/6 "2015-03-25T06:04:37Z")
> [@coremelt](#): > > I don’t see why any species would go extinct, except for a very few that don’t currently exist in the wild and are only kept alive through captive breeding programmes. Any species dependent on human intervention for survival will, by definition, become extinct. This isn’t just the species that are kept alive in zoos. It’s those species that are being kept alive by constant [programs to control predators](https://en.wikipedia.org/wiki/Kakapo#Kakapo_Recovery_programme), weeds or fire, those that are dependent on human supplemented feeding of wild populations and so forth. There aren’t huge numbers of these species, but I would imagine they number in the thousands. To that we can add the species that don’t need any assistance at the moment, but that are ultimately dependent on human modifications of the landscape that aren’t intended to assist the species. It’s hard to say for sure how many such species there are, probably a few thousand more. ---
**Author:** ![Terminus\_Est](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/terminus_est/32/3087_2.png) [@Terminus\_Est](https://boards.straightdope.com/u/Terminus_Est)\ **Post date:** [March 25, 2015, 6:14am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924/7 "2015-03-25T06:14:02Z")
Head lice and pubic lice live only on their respective areas of the human body and infest no other species (which have their own species of parasite.) These two species of louse would be toast if humans were to go extinct. Among plants, maize is absolutely dependent on human propagation due to the ear being enclosed by several leaves. Offhand, I can’t think of any other crops for which this is true. ---
**Author:** ![coremelt](https://avatars.discourse-cdn.com/v4/letter/c/4491bb/32.png) [@coremelt](https://boards.straightdope.com/u/coremelt)\ **Post date:** [March 25, 2015, 6:18am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924/8 "2015-03-25T06:18:13Z")
The IUCN Red List of ‘extinct in the wild’ species is here: > **[IUCN Red List extinct in the wild species](https://en.wikipedia.org/wiki/IUCN_Red_List_extinct_in_the_wild_species)** > > Version 2014.2 of the IUCN Red List of Threatened Species identified 78 (40 animal, 39 plant) extinct in the wild species, subspecies and varieties, stocks and subpopulations. > For IUCN lists of extinct in the wild species by kingdom, see: It’s only 79 species, I would have expected much higher, as Blake points out this doesn’t include ones kept alive through predator elimination programs. ---
**Author:** ![DataX](https://avatars.discourse-cdn.com/v4/letter/d/e99b99/32.png) [@DataX](https://boards.straightdope.com/u/DataX)\ **Post date:** [March 25, 2015, 6:20am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924/9 "2015-03-25T06:20:00Z")
> [@Terminus\_Est](#): > > Head lice and pubic lice live only on their respective areas of the human body and infest no other species (which have their own species of parasite.) These two species of louse would be toast if humans were to go extinct. > > Among plants, maize is absolutely dependent on human propagation due to the ear being enclosed by several leaves. Offhand, I can’t think of any other crops for which this is true. Damn - you took my pubic lice answer, but yours was more complete anyway. The Daily Show had an interview with some researcher in the last year or so talking about how the relatively recent shaving bald trend has made it difficult to find specimens of pubic lice… ---
**Author:** ![buddy431](https://avatars.discourse-cdn.com/v4/letter/b/6a8cbe/32.png) [@buddy431](https://boards.straightdope.com/u/buddy431)\ **Post date:** [March 25, 2015, 6:23am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924/10 "2015-03-25T06:23:47Z")
> [@coremelt](#): > > I don’t see why any species would go extinct, except for a very few that don’t currently exist in the wild and are only kept alive through captive breeding programmes. Dogs, cats, horses, chickens, pigs, sheep and goats all have existing feral populations in various parts of the world that would thrive without us. > > Lots of heavily domesticated breeds would die out, but their feral cousins who are the same species, would survive. Some of those feral populations depend heavily on humans though. I’ve heard speculation that feral dogs, for example, would eventually be out-competed by wolves were humans to completely disappear (at least where wolves exist). Feral cats seem to depend pretty heavily on people too, and I don’t know much about feral chickens, but they seem to live fairly exclusively around people. Now, I’m not sure any of those would strictly go extinct. Dingoes prove that dogs can do OK in the wild, at least when they don’t have too much competition. Domestic cats are very little changed from wildcats, which themselves seem to do fine for themselves even without humans. I don’t know how much chickens have changed from the jungle fowl they are derived from, but I can imagine them doing OK in the tropics. I do think it’s safe to assume that all of these species would be drastically reduced in number, even compared to the feral populations that do exist today. ---
**Author:** ![Horatio\_Hellpop](https://avatars.discourse-cdn.com/v4/letter/h/e5b9ba/32.png) [@Horatio\_Hellpop](https://boards.straightdope.com/u/Horatio_Hellpop)\ **Post date:** [March 25, 2015, 6:27am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924/11 "2015-03-25T06:27:03Z")
About fifteen years ago I heard a scientist on TV address this. He said one type of lice feeds in human eyebrows, and it would die without us. Head and pubic lice would adapt to some other species, but eyebrow lice would not. Sorry, no cite available. ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [March 25, 2015, 6:29am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924/12 "2015-03-25T06:29:59Z")
Only a handful. Cows are extinct in the wild and I don’t see them surviving predation well enough to breed back to an Aurochs-like form. Possibly one or two other animals that exist only because of ongoing captive breeding programs. Pandas might recover as their habitat recovers, but might not. Then there’s all the parasites, like **Terminus Est** said. But also the less-harmful ones, like _Demodex_ mites etc. ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [March 25, 2015, 6:32am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924/13 "2015-03-25T06:32:28Z")
> [@Horatio\_Hellpop](#): > > About fifteen years ago I heard a scientist on TV address this. He said one type of lice feeds in human eyebrows, and it would die without us. Head and pubic lice would adapt to some other species, but eyebrow lice would not. Sorry, no cite available. [Mites](http://en.wikipedia.org/wiki/Demodex), not lice. And I don’t think the head and pubic lice would adapt, other species already have their own successful lice, plus human anatomy is different enough from any animal the lice are likely to try and migrate to. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [March 25, 2015, 6:38am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924/14 "2015-03-25T06:38:45Z")
> [@buddy431](#): > > Some of those feral populations depend heavily on humans though. Some populations, yes. All population, definitely not. > [@](#): > > I’ve heard speculation that feral dogs, for example, would eventually be out-competed by wolves were humans to completely disappear (at least where wolves exist). Firstly, they are the same species, so _Canis lupus_ can’t be driven to extinction by _Canis lupus_. And secondly, as you note, there aren’t many wolves in Brazil or New Zealand. > [@](#): > > Feral cats seem to depend pretty heavily on people too I don’t know where you live, but that isn’t true in Australia or the Americas, and the rest of the continents have functioning populations of genuine wild cats, so what happens to the ferals has no impact on the species. > [@](#): > > and I don’t know much about feral chickens, but they seem to live fairly exclusively around people. Nope. Plenty of populations of feral chooks with no human contact, and there are stable populations of wild jungle fowl to boot. So risk of extinction is nil. > [@](#): > > I do think it’s safe to assume that all of these species would be drastically reduced in number… Without a doubt. There won’t be 10 billion jungle fowl a week after humans become extinct. But there weren’t 10 billion 10, 000 years ago either, so that doesn’t men they are on the road to extinction. > [@](#): > > …even compared to the feral populations that do exist today. I would expect in increase in the numbers of most of those animals. Populations of feral animals are heavily controlled by humans in the modern world. Without that control the population of most species would explode. This is a good example of the type of unintentional human management that is keeping a lot of species alive. While populations of feral dogs and camels are controlled primarily for economic reasons, many species are likely to be exterminated by them if that control is removed. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [March 25, 2015, 6:44am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924/15 "2015-03-25T06:44:10Z")
> [@MrDibble](#): > > Cows are extinct in the wild and I don’t see them surviving predation well enough to breed back to an Aurochs-like form. Feral cattle are a significant problem in places such as Australia, Indonesia and Argentina. They aren’t going to become extinct. Oddly, feral cattle are one of the main threats to the existence of the banteng in Indonesia. So without human control, that species may actually be driven to extinction in that region by the feral animals. Ironically, a stable feral population will continue to exist in Australia. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [March 25, 2015, 7:26am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924/16 "2015-03-25T07:26:39Z")
I wondered about cattle, whether this whole somebody (some human)-has-to-milk me would spell their doom. But I figured eventually enough old ones and little ones would die off so their big old udders would get milked the nature intended, by their calves. Also, out-of-the blue: are you previous raft of posters Aussies, considering geographic citations and ungodly hour here in NYC? (Don’t need answer fast.) ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [March 25, 2015, 7:37am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924/17 "2015-03-25T07:37:49Z")
> [@Leo\_Bloom](#): > > I wondered about cattle, whether this whole somebody (some human)-has-to-milk me would spell their doom. That’s only dairy cattle. Beef cattle are largely maintenance free. > [@](#): > > Also, out-of-the blue: are you previous raft of posters Aussies, considering geographic citations and ungodly hour here in NYC? (Don’t need answer fast.) I’m in Oz. He’s in southern Africa somewhere, where it’s breakfast time. ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [March 25, 2015, 7:40am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924/18 "2015-03-25T07:40:18Z")
> [@Blake](#): > > Feral cattle are a significant problem in places such as Australia, Indonesia and Argentina. They aren’t going to become extinct. Aah, thanks, didn’t know that. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [March 25, 2015, 7:40am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924/19 "2015-03-25T07:40:41Z")
Three kinds of lice are going to lose their favorite meal. Maybe they’ll find other hosts. ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [March 25, 2015, 7:41am UTC](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924/20 "2015-03-25T07:41:54Z")
> [@Leo\_Bloom](#): > > I wondered about cattle, whether this whole somebody (some human)-has-to-milk me would spell their doom. This isn’t the case with meat cattle, I don’t think. ETA ninjaed 🙂 > [@](#): > > Also, out-of-the blue: are you previous raft of posters Aussies, considering geographic citations and ungodly hour here in NYC? (Don’t need answer fast.) Some OZ, some South African… [Next page](https://boards.straightdope.com/t/all-humans-vanish-how-many-other-species-die/715924.md?page=2)