With their rotting flesh, tattered clothes and sunken eyes, the zombies will be easy to spot this Halloween.
But if just one of those costumed trick-or-treaters turns out to be the real deal, even a medium or large city would be overrun by the undead in under a week.
Robert Smith? has done the math and says such a population would be consumed by a zombie plague in five or six days.
A mathematics professor at the University of Ottawa, Smith? creates statistical models for infectious diseases. In 2009, he published a theoretical model for a zombie virus.
Smith? — who legally added a question mark to his name to differentiate himself in the academic world — says there would be pockets of survivors in a medium-sized city such as Ottawa or Edmonton or even a bigger city such as Vancouver, Montreal or Toronto.
Survivors would be those who were lucky, randomly immune or found a good hiding spot — but the majority would rapidly join the ranks of the walking dead. The odds of survival are even more bleak for those who live in surrounding suburbs.
“Everything is on the same level, so the zombies can run around door-to-door and there’s not really any defendable places,” Smith? says of the suburban landscape.
“But in the high-density places like right downtown, suddenly you can go up in buildings and that’s a harder thing for a zombie to do.
“It has to operate doors, it has to go up stairs, and it kind of has to know you’re there. . . . If the zombies are running around at ground level and you’re up on the 15th floor, that might be a perfectly safe place.
“Of course, you’d still have to go out to get supplies, but that’s true of anywhere.”
Jason Tetro, a University of Ottawa microbiologist and immunology expert, has more bad news for the ’burbs: In a zombie outbreak, any large-scale police or military presence would likely be drawn to highly infected areas in the city centre — leaving the ’burbs to largely fend for themselves.
COUNTRY FOLK SAFEST
Residents of the small villages and towns surrounding a major urban region have the best shot at survival.
“You’d want to live in an area with low population density,” Tetro says.
If you live in a small town or village, “you’d probably have a better chance of missing the infection than you would if, say, you lived [downtown].”
Those in the public service or working for large corporations are highly susceptible to joining the undead ranks.
“There’s a very good likelihood you would become infected simply because that [virus] would spread [quickly] in a very localized area,” Tetro says of sprawling office complexes.
But in a theoretical battle against the undead, Smith? said, a city may have some key geographical advantages: rivers and bridges and, in some regions, harsh winters.
“Zombies have trouble with natural geographic obstacles. They’re going to trip over things. They’re not so good at inclines,” Smith? says.
“In the winter, of course, we could do really well because [in a colder climate] the zombies would freeze. But then in the spring the zombies would [thaw] and you’d have zombies coming back to life [underneath the melting snow], but you wouldn’t know where they are.”
DIEFENBUNKER FINDS A USE
Zombie expert Dave Alexander says waterways could be used to navigate the city or to create and fortify a defensible position, depending on whether “your dead can swim or not.”
“I think Ottawa would do extremely well if there [were] an outbreak,” says Alexander, editor-in-chief of Rue Morgue, a Canadian horror magazine.
“It’s not the size of Toronto, but it has a large police, military and security presence because the seat of government is there...Ottawa would be your best urban place [in Canada] to be caught in a zombie apocalypse.”
Alexander says Ottawa has one further major defence against the zombie hordes: the Diefenbunker, the four-storey underground bunker built to protect the government from a nuclear attack.
“If there was a zombie apocalypse, as long as the government could get there in time, that place is pretty much ready to go — you could wait it out,” Alexander says.
The zombie virus would spread rapidly via commuters and a city’s public transit system. If zombie-ism behaved like a highly contagious virus, such as the flu, Tetro says, an isolated outbreak would quickly lead to mini-outbreaks across many neighbourhoods and suburbs.
Tetro says a single zombie case could easily multiply and number in the thousands within 72 hours.
The incubation period of the virus would play a key factor. If those infected don’t display early symptoms, there’s almost no chance a proper quarantine would be put in place, Tetro says. In the beginning, victims of isolated attacks would likely just be treated and released.
“Because everybody comes downtown, or goes to [various shopping malls], you could see it spreading all over the city in a matter of just a few days.”
With the popularity of TV’s The Walking Dead and the hotly anticipated 2013 release of the movie World War Z, zombies are clearly getting under our skins.
If the undead rise, the experts have some advice for urbanites planning their escape.
For starters, even major urban centres offer many low-population surrounding areas. If you can get out of the city, Smith? suggests finding an island on a nearby body of water.
“Zombies can still walk underwater, in theory, but they have to have some reason to do it,” he says. “[On an island], you can pick them off one by one from a safe place.”
Bryony Etherington, organizer of Ottawa’s annual zombie march, says any nearby armed forces base might offer the “safest” location to wait out a zombie crisis. But it could also be overrun by people with the same idea.
Images of abandoned vehicles on highways are common in most zombie fiction, and Tetro says gridlock would likely occur on major exit roadways.
But Etherington offers one solution if the roads get jammed by panicked drivers: Get your hands on a boat and flee by water, if you can.
But the experts agreed that Ottawa would be far better off than Toronto, or Vancouver in an outbreak. If the densely populated Toronto or Vancouver faced a zombie virus, it would spread through the city in a wave, and the whole region would be infected in days. There would be nowhere to run.
Only one of Smith?’s mathematical models resulted in humans surviving in large numbers — one based on humans mobilizing early and mounting a series of “extremely aggressive” attacks against their zombie foes.
“It’s all about co-ordinated aggressive attacks. If we have tanks and if we have armies and so on that are coming in en masse, then we can overwhelm the zombies,” Smith? says.
But he’s not optimistic a city population could move swiftly enough. To be effective, such offensives would need to begin on the second or third day of an outbreak.
“We see that with [real] diseases...If you hit them aggressively and hit them hard, yes, you can turn them around,” Smith? says.
“We could have turned HIV around, but it would have required all this co-ordination to happen early in the epidemic.
“If we can’t do it in real life for a life-threatening disease, which is much easier to control than zombies, what chance do we have in a zombie epidemic?
“I think civilization gets overwhelmed pretty quickly. Trying to get Parliament to pass bills is a slow process. It’s hard to get them to agree on anything — getting them to co-ordinate an aggressive response within a few days is really, really hard.”
Being in an isolated city could also prove fatal. If an outbreak began, such a city could be easily quarantined — trapping the zombies along with whatever survivors remained.
“Lots of other cities bump up against each other, but it’s not like we’re in walking distance of Montreal or anything,” Smith? says of Ottawa, for example.
“If you were able to put a blanket zone around us or drop a nuclear bomb on Ottawa, [you could contain the spread].”
LIBRARY LOOKS GOOD
If escape to an army base or bunker is not an option, the zombie experts offered some advice on where urbanites might be able to hide inside the city.
“A really good place is a library. Most libraries have one exit, which is easily defendable,” Smith? says.
“You have all the information you need, in terms of looking up how to rebuild
civilization, and multiple floors to hide out on.”
Etherington says she’d seek shelter at a major government, academic or corporate complex — “somewhere with food, kitchen resources and security.”
She admits to constantly rethinking her strategy for dealing with a zombie invasion. She knows it’s just fiction, but better safe than sorry.
“The advantages the zombies have is they don’t need to sleep, they don’t need to eat — they just keep coming at you — and no matter how many you kill, there are going to be a thousand more on their way,” Smith? says.
“That’s an enormous advantage they have as a predator.”
This Halloween, maybe it’s time to sit down with your family and come up with your own zombie survival plan. Better to use your brain now before something tries to eat it.