Lying camouflaged amid the deserts and grasslands of southern California, the western diamondback rattlesnake is one of the most patient predators in the world.
These snakes live largely solitary lives, hidden away waiting to ambush their next meal. It can be a long wait. If necessary, they can go for two years without feeding, but when a chance arises they are among the deadliest and most efficient carnivores on the planet.
And like all snakes, their first weapon is not size or strength, but sheer speed.
According to research published in March 2016, an average snake strike lasts somewhere between 44 and 70 milliseconds.
To put that in perspective, it takes humans around 200ms to blink an eye. In the same time, the most ruthless snake could theoretically have carried out four strikes.
It is almost inconceivably fast, and it means that snakes are far better at striking their prey than we are at moving any part of our bodies.
In fact, if we were to move at the sort of accelerations that snakes do, we would black out.
“Essentially the prey doesn’t stand a chance in most encounters,”
says David Penning of the University of Louisiana at Lafayette.
He spent months observing the rattlesnakes, as well as a variety of venomous and harmless snakes, using a high-speed camera.
“We’re talking about animals that can strike out and reach their target before the prey is even perceptually aware that it’s under attack.”
It is not just rattlesnakes that can move this fast.
Of the estimated 3,500 snake species on the planet, from the tiniest vipers to the biggest pythons, very few have been studied.
But of those investigated to date, many are capable of generating these mind-boggling accelerations.
This is down to snakes’ unique physiology, which has been finely honed over millions of years. For one thing they have a lot of muscles. The human body contains somewhere between 700 and 800 muscles. Snakes, even those so small they can sit on a coin, have between 10,000 and 15,000 muscles.
We do not yet know how snakes exploit these muscles to move quite so explosively. Some believe that they all connect together, building up energy for the strike before springing in one elastic movement, like a rubber band.
But one particular aspect of snake attacks is even more baffling. Because they attack in such a short space of time, snakes have to withstand extraordinary forces on their bodies: forces that would completely incapacitate virtually any other animal.
Penning found that snakes experience forces of up to 30G – 30 times the force of gravity – when accelerating towards their prey.
In contrast, even the most highly-trained fighter pilots lose control of their limbs at 8G, when performing extreme manoeuvres for short periods of time.
Any more than 10G, and they quickly lose consciousness.
“We know that chameleons and some salamanders shoot their tongues towards their prey when attacking, and they can hit accelerations which are many, many times greater than snake strikes,” says Penning. “
But the key difference is that the tongue is travelling, not the brain.
“Brains simply cannot withstand powerful acceleration. “
The brain is an incredibly delicate organ that is super-sensitive to accelerations and impacts, says Penning.
“That’s why American footballers have helmets and concussions are such a serious thing.”
When a fighter pilot experiences strong accelerations, blood is pushed towards their feet, depriving their brain of vital oxygen. If this happens too rapidly, the blood cannot return to their brain quickly enough and they lose consciousness.
But snakes manage to circumvent this and remain fully in control, all while moving at far greater accelerations and striking their prey with enormous force.
Part of the explanation may lie in the structure of their skulls.
“The skull of a snake is incredibly kinetic and mobile,”
“There are so many different joints which allow stretching and mobility. It could be that if one part lands first, it can absorb a little bit of shock before that’s transferred to another part, so the snake can absorb the impact of the strike far easier and it doesn’t concuss them.”
Penning compares it to
“punching a bag rather than a brick wall.”
As he puts it,
“the wall isn’t moving that much to absorb the impact, while the bag moves to displace some of that feeling.”
Scientists are now trying to understand how the snake skeletal and nervous systems behave under such extreme conditions. The goal is to use that knowledge to make ourselves safer in scenarios where our own bodies might be exposed to large forces.
The idea of snake attacks inspiring us to design safer vehicles that do a better job of protecting us from the impact of crashes may seem rather ridiculous. But the reality is closer than you might expect.
“We’re currently trying to work out exactly what happens on impact when the snake hits its target,”
“Snakes are able to launch their heads, stop, immediately withdraw to a defensive position and then repeat this again and again and again. So the question is, what is it about them which enables that impact to be sustained relatively easily, and can we use that for our own benefit in the future?”