So, nuclear war is on the horizon. I’m order for humanity and Earth to survive on, organizations, both public and private begin to construct massive underground shelters, each with the ability to house up to 500-800 people, and produce food and water for them to survive indefinitely.

These people plan to repopulate to the world once the nuclear winter ends, but one thing they must bring with them...is animals and plants. Since the nuclear war will cause a mass extinction, as well mutating the few surviving creatures, the people of the underground will have to save them (mostly by cryo-storing dna samples). But they don’t want to waste resources.

My question is, for these people, what animals, and plants, will be most important to save?

Important Info

-Ocean life is mostly fine; algae and whatnot will still be producing oxygen. Insects as well.

-The humans main focus when the emerge will be farming, but they also want to be able to set up a stable ecosystem.

-This is all taking place in the North American continent.

-The limit is....10 different animals. No limit for plants.

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    $\begingroup$ I find it hard to accept the limit of just 10 for each species. Just think how many seeds you could easily store. Most probably they would concentrate on plants rather than animals. But it would completely depend on the story constraints. $\endgroup$ Jul 3, 2020 at 19:50
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    $\begingroup$ If there is no limits for plants, we already have seed banks with vast amounts of samples en.wikipedia.org/wiki/Svalbard_Global_Seed_Vault $\endgroup$
    – user69935
    Jul 3, 2020 at 20:12
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    $\begingroup$ You know, there's this thing called minimal viable population which is basically the minimal amount of animals of each species necessary to allow their continued existence without issues related to inbreeding. If you're planning on taking these animals to save them from extinction, you might want to leave a larger place reserved for them, because it'll take much more than 10 (the minimal amount of humans theorized is around 100 in the ideal conditions). $\endgroup$ Jul 3, 2020 at 20:23
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    $\begingroup$ @ProjectApex: No no no. They’re going to keep 10 different species not 10 animals from each species $\endgroup$
    – DT Cooper
    Jul 3, 2020 at 20:25
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    $\begingroup$ @DT Cooper oooh, that makes a lot more sense. In that case the best candidates would be animals used as livestock and different dog breeds (which all are considered as a single species) to comfort the humans and help protect the livestock from the new wild animals once they leave. I'm looking at chickens, turkeys, horses, cows, buffaloes, dogs, pigs, boars (?), ostriches and kangaroos as some of the most likely candidates to be saved (kill all emus if you can't take them, we don't need emus to be turned into more dangerous creatures thanks to magical mutagenic radiation). $\endgroup$ Jul 3, 2020 at 20:31

4 Answers 4


Disaster no matter what

There's a lot of complexity involved in re-introducing animal species that have died off in the wild. For our purposes, I'll focus on a major problem your survivors will face no matter what they decide: food chains will be destroyed

In order to support any given animal, you'll need a whole chain of things to support that creature. Below is one example from Wikipedia. Re-introduction of a species requires that the species has an intact food supply, which generally requires numerous other plant and animal species.

Example of a food chain from Wikipedia

I love cats. So let's say I wanted to include cats as part of the post-apocalypse plan. Cats generally eat meat. So I might have to include birds or small rodents in my plan as well. And what do birds and small rodents eat? Well my favorite bird is the Black-Capped Chickadee, so I guess I'd reintroduce them too as prey for the cats. What do chickadees eat? According to NWF, "They eat a diet of seeds, berries, insects, invertebrates, and occasionally small portions of carrion." Hmm, I guess I'll pick earthworms as their food source since they seem important. Worms need plant matter to survive, so I'll choose... hmm... spinach as my plant? So even in this oversimplified food chain, bringing back cats requires three other species, which only leaves six more species for your survivors to take. In the real world, things are far more complex and interconnected.


It's unclear how many of each species your survivors can keep. It's also not clear if you can bring multiple breeds of the same species with you (e.g. would saving Cocker Spaniels and Saint Bernards count as one or two species?). You'll need a lot of members of each species. Scientifically speaking, you need the minimum viable population of each species. This question has good answers with regard to humans. An older rule of thumb is the "50/500 rule" which says that you need 50 of a given species to prevent inbreeding and 500 to limit genetic drift (more info here). If you can only save one breed of a given species, you'd be limiting the diversity that can exist within a species. For example, think about how many kinds of dogs or cattle or chickens or even turkeys there are.

  • $\begingroup$ No no no no. There’s 10 species, you can have as many members of each individual species as you want. $\endgroup$
    – DT Cooper
    Jul 3, 2020 at 20:55
  • $\begingroup$ @DT Cooper you might want to edit your question to make that information clearer, because as it's structured it seems like you're talking about 10 animals of each species rather than 10 species of animals with "no limit" of individuals. $\endgroup$ Jul 3, 2020 at 21:09
  • $\begingroup$ So you're saying Noah wasn't real? $\endgroup$ Jul 3, 2020 at 21:25
  • $\begingroup$ @DTCooper I edited my answer $\endgroup$ Jul 3, 2020 at 22:12
  • $\begingroup$ @chaslyfromUK Reducing the population of every species to one breeding pair would have been disastrous. Plus it would have left pretty clear signs in the DNA of today's species if they had all started evolving from one pair at exactly the same time. I'm a Christian and I think it's pretty clear that the story of Noah is an allegory. I find it alarming that some interpret it in a way that the Bible never intended. $\endgroup$ Jul 3, 2020 at 22:14

Plants in general would prove more essential for survival and require fewer resources to keep.
From plants you can get all nutrients you may need, drugs, clothing material, raw materials for industrial production like rubber and so on.
A variety of mushrooms should be stored (again spores are easily stored) and cultivated in the shelters.
Would be essential to bring in some delicate insect species too: bees, bumblebees, silkworms, etc.
With limited space and time to prepare the shelters they would probably pick smaller animals but capable of fast population growth. Like rabbits (meat, fur) and mice (meat, lab testing). If possible sheep too.
If there is the availability of resources also some donkeys or llamas, depending on location. In case of scarcity of fuels they may provide help for transportation. Also dogs and cats both as pets and in case the population of those rabbits and mice may run out of control.

Ideally they should coordinate the shelters so that each one would have a few different species, depending on available space.

You are the designer of the story so it's up to you... but are you aware there are new studies that have greatly reduced the likelyhood of a lassting Nuclear Winter?

  • $\begingroup$ No no no. The animals are cryo-stored to be cloned later using dna $\endgroup$
    – DT Cooper
    Jul 3, 2020 at 21:42
  • $\begingroup$ If they have "cryo storage" then they must be able to generate the animals somehow anyway. With artificial wombs? If that so your society is more advanced than ours and needs to be clarified more in your question to have any meaningful answer. As it was it sounded like you were talking about present day Earth (with relative tech and political organization). $\endgroup$ Jul 3, 2020 at 23:10

Since the background with the question doesn't state whether cryro-storage of animals/animal ova/sperm is vs isn't feasible, I'll answer assuming no cryro, thus a small population of each animal will be needed (and that'll take precious fallout-shelter space.) This is my best guess to both enable high-protein agriculture via draft animals -- as well as giving deliberately-set-loose animals (when the domestic population permits) start refilling/rebuilding the wild ecology. No list of ten will be perfect. But anyway, here goes:

  1. Chickens

  2. Rabbits

  3. Ducks (alternately, geese, possibly Canada geese.)

  4. Goats (very adaptable/survivable)

  5. Something in the Antelope family, probably Elk

  6. Honeybees (non-Africanized)

  7. Pigs (swine)

  8. Horses (draft/plow animals!)

  9. Cattle (draft/plow, dairy and meat.)

  10. Wolves (the ecology will eventually need a top predator.)

Since the question states unlimited plants (via seeds in sealed containers), I'm not going to try to list them all; plenty of seed and Ag. catalogs for that! What think you?

  • $\begingroup$ +1 for honeybees, it will be essential to have a pollinator! $\endgroup$
    – Mirte
    Jul 4, 2020 at 9:05

Chickens, tilapia, channel catfish, goats, llamas, and maybe turkeys

If you survive the nuclear apocalypse, the first thing you're going to worry about is food. You need a food source that's fast-reproducing, easy to breed, can feed on what little you can find in a post-apocalyptic environment, and can be raised easily. Protein is going to be a big issue, since you can easily store plant seeds. Protein rich plants like soybean and quinoa, or other options like spirula might be hard to obtain in such an environment. You need something that's low maintainance and can be taken just about anywhere.

Answer: I present to you the humble chicken. Chickens...

  • Breed fast, they reach maturity at about 16-24 weeks of age. Broiler chickens can be slaughtered for food at 7-9 weeks
  • Eat just about anything, chickens are omnivores and will eat insects, nuts, seeds, berries, centipedes, etc. If insects survive to any noticeable degree you can find enough food to feed chickens. Chickens can survive pretty much anywhere outside of the polar circles.
  • Can be easily handled. This is a big deal. Horses, cattle, and a lot of large mammal require a lot of husbandry and can be difficult to manage. Think trying to range cattle without having access to horses to herd them or the tools necessary to slaughter and butcher them efficiently. Chickens can be easily herded and killed if necessary. You can kill them by hand, or with a shovel or broomstick if you get a big, aggressive rooster.
  • Can produce food without dying (eggs). This is also very important, as it means you can produce food for people without reducing the very limited head of livestock you have at any given time. Even insects aside from honeybees don't do this on a scale efficiently enough for human consumption.
  • Are easy to raise. Human farms since time immemorial have raised free range to semi-free range chickens. In a post-apocalyptic scenario you might even have an advantage because there are no foxes or coyotes to eat your chicken.
  • Don't require a lot of space. You could technically raise chickens within the confines of a nuclear vault, provided you had sufficient grain. You couldn't do that with sheep, horses, or cattle.

Turkeys are kind of similar, being big chickens if you oversimplify things. However, they aren't as space efficient and can potentially be a little more dangerous. But they have a lot of the same benefits (omnivorous, breed easily, etc.)

Other animals that fit this criteria include tilapia (you can literally raise them in sewage tanks, they're easy to breed, and good to eat) and channel catfish (also easy to raise), as well as goats (a bit hardier than the other major hoofstock). Goats can also produce food without having to kill the animal, and you can also get leather out of them.

Sheep are a bit of a trap, they're originally a mountain species that will survive in the harsh conditions of a wasteland and they produce a very useful substance in the form of wool, but those same adaptations that let them survive in harsh environments will lead them to strip the surface cover from your meager post-apocalyptic soils and send you into a dust bowl, something you probably can't survive on top of a nuclear apocalypse. If you absolutely need wool get a llama, they aren't as destructive and you can use them as a pack animal on top of that.

Horses would be very useful, but are a huge amount of work to feed and maintain. Cattle just don't even bother, the downsides outweigh the benefits.

  • $\begingroup$ The animals aren’t going to be alive while down in the bunker. They’ll be stored within egg and dna samples, and then reintroduced into the wastes. $\endgroup$
    – DT Cooper
    Jul 4, 2020 at 2:35

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