Discovery Channel's most recent programming venture, Eaten Alive, left the internet buzzing with questions last week. In case you missed all the hoo-ha, the trailer claims naturalist and wildlife filmmaker Paul Rosolie will 'enter' the belly of an anaconda in a custom-built, snake-proof suit, covered in boar blood to entice the reptilian to 'eat him alive', with a rope attached to allow for his safe retrieval. We could spend this time weighing in on whether the stunt threatens the animal's welfare (we'll leave that one to you). Instead, in honour of the awesome that is snake biology, what say we take the bait and pose a new question: What would you really have to do to get an anaconda to eat you?
"I have a hard time believing that someone would [or] could actually make this happen," says Auburn University wildlife ecologist Dr David Steen, who has studied North America’s largest native snake, the indigo snake. With Steen to guide us, let's take a little tour of snake biology to discuss some of the obvious obstacles that anyone attempting a stunt like this would face.
Finding the right species
First of all, you can put that Indy-inspired snake phobia to rest ... referring to anacondas as 'man-eaters' is more than a bit sensational. The term anaconda doesn't just refer to one animal, but rather to a group of large constricting snakes. There are four different species of anacondas that we know of, ranging in size from the three metre (9ft) yellow anaconda (Eunectes notaeus) pictured above, to the six to nine metre (20-30ft) green anaconda (Eunectes murinus), the supposed star of Eaten Alive. Though no anaconda species has ever been known to actively seek out hominid snacks (in fact, the only two well-documented strikes were on anaconda researchers), the reality is that most of them couldn't snack on us even if they wanted to.
Building the right suit
In the unlikely event that you've landed yourself in a snake's 'loving embrace', the animal will be relying on cues from your body to tell it whether to move on to the 'nomnomnom' stage or to give up altogether. The goal of a snake squeeze isn't to crush prey ... it's to suffocate it, explains Steen. "When constricting prey, snakes try to restrict air flow until the animal stops breathing. Their grip becomes tighter and tighter [over time] as air is expelled," he explains, adding that any suit made of material that is unlikely to bend in response to a snake's grip should in theory help the wearer escape a snake's constriction unharmed. Research has also shown that constrictors have the remarkable ability to detect their prey's heartbeat, and start to relax their grip only as the heartbeat slows and eventually ceases. A wild snake would not attempt to swallow something it didn't perceive to be dead.
Green anacondas have been clocked squeezing prey at an impressive 84 psi ... but what many people don't realise is that doing so is energy expensive (an anaconda's metabolism kicks up seven-fold when squeezing!), and as such, a snake is unlikely to attempt to waste energy trying to eat something that won't be easily killed or that does not make up part of its natural diet.
Having 'snake meal appeal'
For the purposes of this serpent-spilunking analysis, we're going to assume that you've beaten the odds: your super-suit is hard enough to protect your skeleton (we would not want to be part of the material testing phase!), blocks your heartbeat from being detected, allows you to breathe incognito and gives the snake the unlikely impression that you're a food source. You may now pass go and collect $200. But there is one major obstacle we haven't touched on yet: wild snakes are not scavengers.
Though your pet snake might be accustomed to eating pre-killed prey, snakes rarely engage in this behaviour in the wild. "I can't imagine why adding blood to a suit would make it more appealing to a snake," explains Steen. This is due in part to the fact that snakes are not well-equipped to scavenge. With the exception of tree-dwelling species, most snakes have relatively underdeveloped eyesight and rely on the abrupt movements, vibrations or heat signatures of passing animals to alert them to a potential meal. If you want to entice your reptilian opponent, your tough snake-proof suit better let some of that body heat through and you'd better start throwing shapes (for best results, we suggest 'The Carlton Dance').
Getting inside the snake
While deer, capybara, turtles and caimans make up the majority of a green anaconda's diet, from a strictly physical standpoint, swallowing an adult human doesn't escape the realm of possibility for an extremely large specimen. Snake jaws are not fused to the braincase like they are in other vertebrates, but rather float loosely connected by extremely flexible ligaments – the bigger the snake, the wider the mouth can stretch (it's a common misconception that snakes dislocate their jaws to accomplish mind-boggling feats of 'open wide'). "There is actually very little evidence that a person has ever been killed by a green anaconda, let alone eaten. This is not to say, however, that it's not possible," clarifies Steen.
But we have to remember that your custom-built super-suit keeps you from being crushed, and therein lies the problem. Without being able to manipulate your bones, it is unlikely that the snake would get past your shoulder girth without reaching its physical limit, or simply becoming disinterested and giving up. Unless you are one seriously svelte human, there is just no continuing down the anaconda's slimy digestive tract.
Finding your way out
This is a simple case of what goes down must come up. "If the snake was big enough to swallow the prey, I think it would be relatively straightforward to have it come out again, especially because it's going to be, er, condensed and slimy," Steen explains.
He also notes that snakes will intentionally regurgitate prey when the need arises ... but that doesn't mean it's a pleasant experience. "It's hard for a snake to escape predators when it has a big meal inside of it," he says. "If they are threatened or harassed they will regurgitate a recent meal so they can move faster, [but] a key point here is that the snake needs to be made threatened or stressed out [for this to happen]."
And there is a big difference between regurgitation and having your food pulled out from inside of you – this is where things could get a bit hairy for the snake. "It's not hard to imagine some serious abrasions or even fatal internal injuries occurring as a result," says Steen (and this particular concern has caused the biggest outcry from the public). But what is being largely overlooked is that getting this far in the process is extremely unlikely. Discovery claims neither the predator nor the alleged prey were hurt during the filming of the show, so we're going to wager that things are not quite as they seem.
"In any case ... snakes are fascinating animals that are not well known by most people and that is probably why they're so feared. It's a shame when television programmes try to capitalise on this fear instead of alleviating it," says Steen.
Top header image: Jeff Kubina/Flickr