Mathematical Models on Vampire Population Strategies or How to Stop Your Vampires From Wiping Out Humanity

And the award for longest blog title goes to….

But seriously (really?) it’s a real problem.  The majority of vampire novels, Stoker’s included, don’t consider the logistics of vampire to human ratios or how long it would take their vampire populations (the predators) to wipe out humanity (their prey) – around a 165 days for Dracula in case you’re wondering. You might be surprised to find that this has actually been worked out by a number of academics who have published papers on their findings (see links at the bottom of the post) and as I’m currently in the middle of writing a novel with vampires in it it suddenly looked like a good idea to waste an afternoon reading them. Also, I’m always on the lookout for a possible dissertation subject that will make my Academic Advisor roll his eyes.

These maths equations are mesmerising…

Most of these papers use a Lotka-Volterra system (1) that gives equations for working out how natural world predator-prey populations change or adapt over time. We know that fluctuations in one population affects the other, a reduction in prey results in a reduction in predators, but also, in the natural world, predators (lions, tigers etc) and their prey (antelopes, buffalos etc) both have a finite lifespan that results in natural death, whereas vampires live forever, so the model has to be altered in order to compensate for this and other certain variables.

One paper (2) uses a very simple equation to work out how long it would take for the entire global human population to be wiped out entirely. They begin with one single, solitary vampire and a human population of over 500 million and calculate that if vampires only fed once a month, we would all be dead (or undead) within two and a half years. Their reasoning falls down however, because they assume that every human being fed upon will turn into a vampire. As a result vampire numbers increase exponentially and humans reduce exponentially.

But we know that not all bitten humans turn, nor do they all die.  And vampires are still rational thinking beings (mostly), capable of understanding that if they eat or turn their entire food source it’s going to cause problems for their own survival. Something normal human beings don’t seem to be able to grasp, given their continuing destruction of the planet they live on – but that’s an argument on a different subject.

A more sophisticated model by Hartl and Mehlmann (1980) (3) introduced the birth rate of humans and the death of vampires by vampire hunters, as well as optimal rates of feeding that showed vampires would have to manage their resources if they were to survive. Appalled by what he saw as the authors attempt to help vampires “solve their intertemporal consumption problem” (4), D Snower wrote a paper in which he proposes that a human labour force be put to work producing stakes with which to destroy vampires, the more vampires that exist the more stakes are needed. However, he does not seem to take into account that stakes (depending on which vampire infested universe you happen to be in) could be used more than once. In Buffy for example, one human could kill any number of vampires which turn to dust on staking, whilst in other milieu vampires can be revived after a stake is removed from their chest.  He then goes on to prove, through some mathematical equation I can’t possibly hope to understand or explain, that wiping out vampires completely would not be good for the human race!

Finally, a paper published in Applied Mathematical Sciences in 2013 (5) used the same nefarious reasoning as paper 2 to show that in Anne Rice’s Vampire Chronicles it would take Lestat and Louis 48 years to eradicate humans from the world, but again they forget that Lestat was not the only vampire in existence when he turned Louis. There is no mention of Armand, the Theatre de Vampires or Marius, Pandora etc etc, their reckoning is wrong.  Ok it’s only a hypothetical mathematical model, but I say if you’re going to do something based on a fictional world you should at least do it right. They then came to the conclusion, using Meyer, Harris and Kostova’s books,  that certain conditions would result in a peaceful co-existence of vampires and humans where both species could survive in a world not too dissimilar to our own. The balance was fragile though, and any deviation from the appropriate conditions might bring the whole thing toppling down.

At the end of the day, all of this only matters if you think fictional worlds should conform to real world science – which I don’t. Or at least I don’t believe that real world science has all the answers which certainly helps when you write about angels, fairies, demons and vampires. In Persephone Reborn I intend keeping my vampire population in check by using a system of human/vampire co-operation in which some humans are aware of and work for and alongside vampires while the majority of humans are oblivious to their existence. In addition, at some point in the past, an organisation called The Covenant came into being for the sole purpose of regulating vampire numbers and ensuring they abide by a set of rules that, should they be broken, will have dire consequences. Of course, there’s always someone, somewhere, willing to break the rules…

Nel Ashley is the author of Blackfeather – a Fallen Angel Paranormal Romance  and Immortal, the second book in the Blackfeather Series. She is currently working on her third novel, Persephone Reborn, a vampire romance influenced by Greek mythology.

You can also connect with Nel on Facebook and Twitter


2. Cinema Fiction vs Physics Reality Ghosts, Vampires and Zombies Costas J. Efthimiou and Sohang Gandhi

3. The Transylvanian Problem of Renewable Resources by R. Hartl and A. Mehlmann

4. Macroeconomic Policy and The Optimal Destruction of Vampires by D. Snower

5. Mathematical Models of Interactions Between Species: Peaceful Co-existence of Vampires and Humans Based on the Models Derived from Fiction Literature and Films  by Wadim Strielkowski , Evgeny Lisin  and Emily Welkins






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