Snakes, seascapes, and the value of nature
It's called an "enigmatic" decline: animal species and populations dying away for no reason that anyone can discern.
When there's a trend without an apparent cause, the questions come thick and fast.
One senses that herpetologists all around the world will be asking some of those questions now, in the light of a scientific paper suggesting that snakes are in decline globally - a decline especially marked, in many of the populations studied, since about 1998.
It would be easy to overdo the concern here.
Data is phenomenally scarce; and it could be that when more research comes in, as the scientists hope it will, the picture will look less alarming than the one they've painted - of marked falls in population size, several of 80-90% in little over a decade, sometimes in areas where the snakes are protected.
Herpetologists are familiar with enigmatic or idiopathic declines. Nearly two decades ago, a widespread pattern of decline was noted in amphibians - particularly frogs - and turned out to be largely down to a disease that no-one even knew existed, the fungal infection chytridiomycosis.
There's no evidence yet of such a disease sweeping through the world's snakes; but you can be sure the question will now be asked.
Amphibians - as we've discussed before on this blog - are also threatened in various areas by pollution, hunting, collection for the pet trade, and above all by the expansion of human habitation.
Could such a mix of factors also be behind the snake findings?
Mention of the year 1998 inevitably raises the question of climate.
The year saw abnormally high temperatures in many parts of the world, due to the combination of the long-term warming trend and particularly vigorous El Nino conditions; could this have affected the snakes directly, or their prey, or their reproduction - and could it really have done so on three continents?
The jury is well and truly out; but this could be the beginning of an intriguing scientific detective story.
It may seem like a leap from the forests of West Africa to the depths of the oceans, but it was one that I found myself making when thinking about how and why we get fascinated by issues such as the apparently falling snake numbers.
Earlier generations, in an era when access to information beyond the boundaries of your community was limited and tools of mass communication were restricted to the written word, had little opportunity to be enthused about the flatfish of the ocean deeps or the rhinoceros viper of West Africa.
For many of us, the earliest glimmerings of fascination came through the writings and films of pioneers such as Jacques Cousteau, whose centenary falls this week.
The Silent World nestled on my bookshelf as a kid, as it did on countless others.
Without Cousteau and his aqualung and his desire to film places and things that no-one else had, would we have reached the stage where every British kid knows what a koala looks like and what it eats, and where people in the hottest countries on Earth are familiar with the shapes and habits of the polar bear?
The interest raised by such figures was probably a precondition for the explosion of environmental awareness in the 1950s and 60s, and led to legislation - especially in developed countries - that placed species and ecosystems under protection.
These have had concrete benefits, no doubt about it; in the snake study I mentioned earler, all the populations not shrinking were under protection plans.
But Cousteau and his fellows didn't get the whole job done. Every year, the Red List of Threatened Species and other publications detail the increasing pressures on nature, and how nature is succumbing; and on a global scale, the pressures go on rising, with inevitable consequences.
Something else is needed, many argue; a more coherent institution that will collate all the available data and present it in structured form, that will set out the ecological and economic costs and benefits of various courses of action, and allow peoples and their governments to make properly informed choices.
By the end of the week, we could have such a body.
Governments are meeting in South Korea with the aim of making a final decision on whether or not to establish such a body.
Its title wouldn't be as compelling as The Silent World - the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) will win few contests for snappiness - but it could potentially give us global snapshots of nature and its value, and how we're losing that value, in a way that's never been done before.
Will it happen? Not sure: some countries, even those rich in biodiversity such as Brazil, are unconvinced, arguing that it's not an international issue and that they can study and look after their own nature.
IPBES proponents say that's all very well - but clearly not enough governments are doing so, otherwise the Red List would be painting a more positive picture each time it comes out.
The new organisation could collate and potentially even commission research on snakes around the world. It could document how much snakes are worth to various societies, in terms of their ecological role as top predators and through more direct channels such as their use for food.
It would arguably complete the information revolution on nature that people such as Jacques Cousteau began in the first half of the last century; and it could provide hard facts that might lead to the preservation of snakes and much, much more, in a way that all the undeniable fascination and sentiment aroused by the pioneering naturalists of yesteryear has not been able to do.
We'll know by the weekend how that situation stands.
As for the snakes - well, that'll probably take years to decipher. Watch this space...