Deep in our tissues lurks a forgotten emotion, forgotten because most of us no longer need it. It is a terrified fascination with our predators – animals whose prey we might be. It is clearly an ancient emotion, and it is clearly potent, and its existence was brilliantly illuminated and tapped into by Steven Spielberg when he directed Jaws in 1975 – creating at the age of 29 what was then the most profitable movie ever made.
Spielberg made our ancient fear of predators manifest, for the first time, to a mass audience. Cinema-goers had not really been scared – I mean scared right down in those tissues – by King Kong or The Beast from 20,000 Fathoms, as these were obvious fantasy creatures. But a killer fish – a great white shark, seen in screen-filling close-up, sinking its great white teeth into holiday swimmers off the coast of Long Island? That was only too real.
Such is Hollywood's power that Jaws fixed the fear of killer sharks in the imagination of the world for a whole generation (the movie grossed nearly half a billion dollars). But unlike our instinctive fear of predators, our fear of sharks is learned. You learn it from your local Odeon, from your DVD player, or from news reports. The fear of snakes is a different matter.
There is considerable evidence that the fear of snakes is inherent in us as in other primates – that human children, and baby chimpanzees, for example, instinctively identify snakes as threatening without having seen them before. You can perhaps understand why: the figures for death from snakebite in modern-day India suggest that between 10,000 and 15,000 people are killed every year by creatures such as the Indian cobra, Russell's viper and the saw-scaled viper, with tens of thousands more being bitten but surviving. It is obviously the case that in some parts of the world, living with snakes in the grass presents a real risk to your life, and did so even more throughout thousands of generations of human evolution.
As a consequence, snake-fright seems to be one of the biggest fears we are born with, along with the similar fear of spiders, and maybe a few other apprehensions, like fear of the dark. And in this context, I was fascinated to learn that Natural England, the Government's wildlife agency, has just embarked on an exercise to improve the health of Britain's adder population.
The adder is our only venomous snake. It is capable of killing an adult human with its venom, although there have only been 14 deaths recorded since 1876 – the last of which was the death a five-year-old child in Perthshire in 1975. Between fifty and 100 people are bitten each year when they accidentally tread on adders or try to pick them up, with about a quarter of these instances resulting in hospital treatment. But for all that, it is the adder itself which is at risk.
In the last decade, Natural England says, Vipera berus has slipped into a decline, largely because fragmentation of its habitat is isolating populations which then begin inbreeding; it is thought that a third of remaining adder populations may comprise fewer than ten adult snakes. So this summer the agency will be surveying adders across England for genetic diversity, and may end up transplanting adders from spots where diversity is high to spots where diversity is low.
It may seem counter-intuitive to say so, but I found the news that the Government intends to spread poisonous snakes around the country to be heartening. It is perhaps the best possible example of how far we have come from our own poisonous prejudices, which once we held against most of the natural world – prejudices that prompted us to eliminate not only creatures that might harm us, but any creature deemed to be in competition with our interests, and that led to the wildlife pogroms of the Tudor vermin laws. That we are now a society that can step outside our ancient fear and share the world with snakes seems to be a mark, even if a small one, of civilised advance.
And anyway, adders are a splendid addition to our impoverished fauna, as I found when I went looking for them last week, by sheer coincidence the very day before the Natural England announcement. I went with Stephen Spawls, a Norwich biology lecturer who also happens to be one of the experts on the venomous snakes of East Africa, an expertise for which he paid a price – he lost his right index finger to a bite from the puff adder he kept as a pet during his youth in Kenya.
On a Norfolk heath we found a two-foot long male adder basking in the sun. Without turning a hair, Stephen flicked it up with his "snake stick" and was suddenly holding it behind the head (on no account try this yourself). He opened its mouth with a twig and showed me its poisonous fangs and invited me to feel its sun-warmed body, before replacing it in the grass, the snake hissing indignantly.
This was something more than the tame England of bluebells and willow warblers, beloved though that is. This was standing a foot away from death (well, potentially), and I readily admit that I felt every ounce of our ancient snake-fear surging out of the tissues. But looking at the beauty of its markings, the dark zigzag down its back and the streamlined perfection of its shape, I also thought it was magnificent, and I was grateful that my country recognised there was room in the world for this creature too.