Worldbuilding: Extradimensional Trophic Levels

AKA why vampire and were-creature “societies” make me cranky. The available energy just isn’t there.

Some background. Biology, so far as we know, works within the physical laws of reality. If you want your monsters to feel real, they have to at least give a nod to how real creatures work. Including how much energy they need to survive and what the likely prey/predator ratio is.

How much energy is available depends on your creature’s trophic level.

Long story very short, the realities of how many genes you can stuff into your DNA and how many different enzymes you can afford to build in your cells means that living organisms simply cannot extract every last drop of energy from an available food source. It’s more effective for survival to strip out the quickest and easiest nutrients and energy you’re adapted to get out of your food, and dump the rest. Other organisms, often microbial, take over breaking it down further and extracting what they can strip out. And so on.

So if you’re a multicellular critter, whatever you’re eating has to be several times more plentiful than you are. A useful biological rule of thumb is, you lose about 90% of available energy with each higher trophic level. So say you have 100 grass clumps, you could then have 10 zebras and one lion. This is why large predators are rare.

You’d think humans were the exception to this rule given how many of us there are, but we cheat. Like bears, we’re omnivores, only we can eat our way even farther up and down the trophic levels than any bear, keeping our population much higher than any available prey base would indicate. And this is why tigers are in serious trouble population-wise, while bears are usually not. Tigers are obligate carnivores. Great if there’s plenty of water buffalo and young elephants walking around, not so great if there’s just fields of grain and insects.

If there’s not enough prey in an area to keep tigers alive, how can your world justify a dragon?

There could be ways. Sleeping on their hoards for decades at a time, magical creations trapped by a spell broken by some poor fool… there are ways. But there’s one I’ve wondered about, given dragons often are magic.

If one world doesn’t have enough available prey for a population of dragons… what about ten worlds?

It’s classic predator behavior in biology. If there’s plenty of prey, you can afford to have more neighbors and guard a smaller territory. If there’s not – you roam over a larger one.

If a dragon eats ten cows in a sitting, and needs to eat even once a month, it’ll cut a bloody swath through even a Western range’s herd. But if it can visit a different world a month for those ten cows – that drops it from “utter disaster” to “dangerous and expensive predator”. Ecologically speaking, this is a more sustainable species.

It probably wouldn’t fit the tone of most fantasy stories, where the characters are mostly in one world, but it’s something to ponder. Especially if dungeons are implied to exist outside the usual space-time continuum.

BTW – while mammalian carnivores can’t subsist on just plants, mammalian herbivores can and will eat meat. Ruminants, in particular, eat the microbes they culture in their guts along with the plant matter, so they get a fair amount of animal protein. The animals just happen to be microscopic.

Take that, Thoreau, and all your grumping about people should be vegetarians because obviously oxen get by with vegetable-made bones….

35 thoughts on “Worldbuilding: Extradimensional Trophic Levels

  1. BTW – while mammalian carnivores can’t subsist on just plants, mammalian herbivores can and will eat meat.

    Horses will deliberately snap at mice running over their food, and eat them if they catch one.

    :faintly green: Yes, horses are freaky.

    Liked by 3 people

    1. As long as they don’t leave the kidneys in the middle of the floor for the unsuspecting human to step on, that puts them one up on cats…

      Liked by 4 people

  2. Gygax suggested that the sun of a campaign setting might have an ever-so-slightly-different tinge to it compared Sol, and the frequency difference happens to be really good for the local plants. Then add a few fast-reproducing prey species and all but the spergiest players should be satisfied. (He didn’t type ‘spergiest’, of course, this being written at the end of the 70s.)

    Alternately, maybe there are plants that you don’t want to cultivate in civilized areas, but in the wild they tend to thrive, because they’re more efficient in turning sunlight and CO2 into plant-stuff. Meaning there’s more food for the herbivores.

    Activist vegans are people you want to get to know in your area: When the zombie apocalypse hits and you’re turned, you’ll know where all the grain-fed meat is.


    Liked by 2 people

  3. I’m a ways from being rested enough for sane commenting, but will get there. (I think the effort spent recently has probably been worth it.)

    Anyway, I hear fantasy and many worlds, and want to rave more about Memories of the Fall. Takes place on the flat world of East Azure, which somehow has a shard of another world buried in it.

    Local polity contains East Azure, West Azure, North Azure, South Azure, and the ruling capital world of Shan Lai. (Okay East Azure isn’t really politically unified, but…) Main characters haven’t yet stepped beyond the bounds of East Azure yet, but I’m expecting that it will occur.

    Liked by 2 people

      1. Ooh. I hope I have a chance to talk to you about it.

        There’s some bits where our tastes might prove to differ.

        I look forward to hearing more about if you like it.

        Liked by 1 person

      1. *snickers*

        “Mister Dragon, we are citing you for baiting bucks. You KNOW that princesses will tempt knights, it’s as forbidden as hunting at the salt lick–”

        Liked by 5 people

  4. This is kind of a point for the “dragon in human form” ‘verses. If the big scaly monster is something it turns into part of the time, and it can eat like a normal human (or even Hei from Darker Than Black), it’s a little more viable for there to be multiple dragons running around without the entire setting being decimated by overconsumption.

    Liked by 5 people

  5. I wonder about possible other non-food sources of energy, in regards to “magical” organisms. The first that comes to mind would be “magical background radiation”, i.e. there’s a source of supernatural potential energy that some creatures are able to absorb. This makes food important mainly as a source of biomass. There could also be the possibility of an adaptation to use radioactive elements in special organs to supply energy, though that’s likely to be harder to suspend disbelief with.

    I have heard though, that there some complex hydrocarbons that actually work well as radiation shielding, they just tend to degrade in a radiation environment. That was part of the world building for McCaffrey and Stirling’s “The City Who Fought” , where the human antagonists came from a world rich in radioactive elements, such that the organisms incorporated them into the biology, using certain biologically created waxes.

    If one thinks of the whole “dragons basking in the sun” theme, well, I think it’s been discovered that chlorophyll is not the only way to use solar radiation in the history of the evolution of photosynthesis, and that other organic compounds have shown potential to be used in generating electricity.

    If an organism can develop in such a way, that matter intake is not synonymous with the intake of energy, you could have a system where the biomass (or inorganic material as well) serves to create and maintain the system that actually provides the energy that sustains the creature. This would probably require a biomechanism for stable/long-term storage of energy. Perhaps even as excrement when there is a surplus.

    The cycle of dragon hibernation, and often preferring mountains for their lairs, could be a hint in a setting, that dragons need access to minerals and ores as a source of energy and dietary supplements well as natural defenses. Perhaps dragons can’t maintain a more consistent/constant level of activity, because they would run out of energy, and collapse. So, they need these periods of “sleep” to build the reserves for active periods. Their intelligence and magical prowess let them leverage their super apex predator status to keep the other intelligent beings at bay, from fear of direct devastating attacks, and by keeping intrigue, rivalry, antagonism, and power plays among the intelligent factions churning.

    If the other more numerous, fecund species/races became aware of the absolute necessity of “rest periods”, they might realize that they could possibly overcome the dragons by forcing them to expend themselves. It would come at quite the cost, though, because the dragons wouldn’t go quietly.

    Liked by 1 person

    1. I’ve given my arguments before on dragon design, that even barely approaching the basic list of things dragons are commonly portrayed as doing cannot work with something like the silly “gas bag dragon” idea… but instead with dragons that are made of metal and crystal, with nuclear MHD circulatory systems and fusion breath and strong magnetic fields aiding defense against weapons. Sure, it takes some careful design and the right way of describing it to make it fit, but anything less than that just doesn’t come close to matching the feats described. Also, as a side feature, this explains why they seek precious (heavy) metals for their beds (and for fuel).

      Liked by 2 people

  6. In most stories I’ve seen, “werewolf societies” don’t get most their food from hunting, they just go buy steak in human form and hunt for fun.

    Vampires take a bit more careful thought.
    They often are shown as a handful of vampires living in a large city, which is plausible-ish.
    But then the author wants to show a “vampire court” which has a few dozen “courtiers” and it starts to wear thin.

    An interesting line of speculation.
    Vampires are often depicted as long-lived, with long-term politics and far-reaching plots.
    But if you go back a millennia, there were fewer people, fewer big cities, and travel between them was much more difficult.
    How much politics would you expect from that?

    Imagine a group of effete city-dwelling vampires encountering an ancient ancestor who is more of a wandering murder-hobo.

    “Oh great Ancestor, what is your purpose here?”

    “I’m feuding with Bob, so every couple decades I burn down his house and run away.”

    Liked by 6 people

    1. Ooh. Now that gives me ideas. Going by the idea of vampires only being able to have notable groups in modern times, and remembering the issues with food supply… what _would_ an ancient vampire, just waking up to this, think of the idea of, for want of a better term “organized vampirism”?

      “Anarchist vampire” sounds like it might be just the villain I need for the FBI Agent vampire story I’ve been wanting to write.

      Liked by 1 person

    2. Mailanka wrote a thing on time frames, mostly in the context of the VTM role playing game.

      Really hammered the point that some of these vampires are supposed to have lived a very long time, and yet the ideas for generating backstory were kinda tending to focus on a few of those periods, in a lot of the same ways.

      I found it very inspirational.

      At the time I was already doing some experiments with space opera cultivator settings, and as a result spent some time nailing down a concept of city dwelling social vampire that I thought tolerable.

      Of course, then I didn’t make use of them to look at the deep time aspects.

      Liked by 1 person

      1. It didn’t have a breadth of ideas? Well, of course: It was the World of 90’s Edgelord, not anything with actual historical substance. These are the same people who decided that demigods conquering a supermagical prehistoric ultra-world would result in them spending all their time getting laid and getting high.

        Wide Woof did druggie counterculture, murderous homeless vagabonds, and Christianity-is-bad-m’kay?.They weren’t going to step outside their comfort zone to do actual research.



      2. Mailanka was focusing on ‘maybe this is a better way to think about player characters’.

        I’d done the thing before of calculating # of generations from a historical period, but he had a pretty good visual explanation of how much variation in social experiences there could have been in five hundred years or a thousand years.

        Liked by 1 person

  7. The other option is kind of the current state of thought for dinosaurs, which is “what is bio available is less difficult to digest, which skews how much you need to support the next level.”

    Also, old style vampires sometimes took six month to a year to kill one victim, and spent the rest of the time either in their coffin or as a pool of blood(and usually in unconsecrated ground, which might mess with absorbing energy.)…maybe you could swing it that as things changed and we got more people, it enabled vampires to actually do more. Most vampires can even stay up all night now!

    Liked by 2 people

  8. “If one world doesn’t have enough available prey for a population of dragons… what about ten worlds?”

    You got my goosebumps going with that idea!

    For other possibilities, then depending on the setting, the ruleset, and DM discretion, dragons can be sapient, spellcasters, and as ToxicSunrise states: shapeshifters.

    For sapience in particular, they could control a cult to grow food for it, or (if the dragon is less evil) enter an arrangement with the local lords.

    Liked by 2 people

  9. If vampires are going to be scarce and uncommon, even in large modern cities, I want to see some vampires set up a ‘court’ through the magic of teleconferencing someday. It neatly bypasses the ‘to many vampires in a city’ issue by allowing the court to cover expanses larger then a city without needing to deal with traveling time issues, and given the internet and how easy it is to travel these days there’d be benefits to vampires not loosing track of, say, vampire hunters just because they skipped cities, or being able to access out of town blood banks if things are getting hot at home, or otherwise using the power multiplier of ‘working together’.

    And it also helps keep the political bloodshed down by preventing the vampires from all being trapped in the same city with each other…

    Liked by 1 person

  10. I tend to explain things like dragons with elemental/magical energy – dragons are creatures part material world, part Something Else that works under slightly different rules. They’re creatures of magic and energy – sure, they can and do feed on things like cows and such, especially when they’re younger, but as they get bigger and older it’s no longer enough to sustain them and they move increasingly into just absorbing the appropriate energy from their surroundings, like a gigantic mystical solar panel. They *can* still eat meat and the like, of course, and tend to enjoy the variety like any other thinking creature would. That red dragon basking in the lava pool? Was actually having supper, and your silly two-leg self looks like a fun crunchy dessert.

    This would also explain the usual dragon magical resistances – they’re already absorbing magic from their surroundings, and a powerful enough dragon can leech most of the energy powering the spell right out of it and shrug off the rest. (Is a Disintegration ray spicy?)

    Likewise, a vampire or similar creature probably is deriving less actual nutrients out of the blood and more using the mystical ‘life force’ or soul-energy of its victim to fuel whatever magic is keeping them undead and animated.

    Similar to how in Warhammer 40,000 Slaanesh has claimed the souls of the Eldar, and is actively trying to suck their souls out of them – while the Craftworld Eldar keep the Dark Prince at bay with willpower and using soulstones to capture the souls of the dead before Slaanesh can get its hands on them, the corrupt Dark Eldar stave them off by instead absorbing energy from the pain of other sentient beings and feeding that to Slaanesh. The stolen energy keep them eternally young and vital, but if they’re denied this external energy they start to fade away as Slaanesh takes their due.

    Liked by 1 person

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