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A kink in the lizard's tale

Richard Black | 08:10 UK time, Thursday, 22 October 2009

By now, you've probably heard .

About one-third of species on the threatened list - some winking out of existence in a single season as the disease extends its fungal tentacles across the continents; nearly 100 species in captive breeding programmes, often because the risk that wild populations will disappear is considered too high for comfort.

But you probably haven't heard this one; the world's reptiles could be in an equally unhappy situation.

Sand_LizardAs yet, there isn't a global assessment of reptiles, although the (IUCN) has begun work on one - more of that in a moment.

In its absence, a group of UK specialists has looked at the data we do have and what it tells us, and asked what we'd see if this limited picture turned out to be representative of the world in general.

You can find it .

And it's not pretty. By their analysis, the prospects for reptiles worldwide could be just as bad as for amphibians.

As is often the case in these matters, there's more data from Europe than from less developed parts of the world; and the UK is especially rich in studies (though not in the number of reptile species), thanks to the long tradition of amateur naturalists.

The first finding these researchers made as they trawled the scientific literature was that both reptiles and amphibians appear to be less well-studied than birds or mammals.

Between 2005 and 2009, one scientific paper was written for every 11 amphibian or reptile species. Mammals and birds notched up one paper for every four species.

Grass_snakeGlobally, only 5% of reptile species are classed as threatened.

But only 16% of species have been properly assessed; and when you ask what proportion of those assessed species are threatened, it turns out to be the same as for amphibians - about 30%.

In Europe, where have been compiled for both amphibians and reptiles, the proportion of threatened species is again the same across both groups.

So on the face of it, it looks as though quite an important global conservation issue is being neglected here; and you might well ask "why?"

I had a quick chat with John Wilkinson of the UK charity , one of the researchers on this study, to get some ideas.

One very simple fact, he points out, is that reptiles are just more difficult to study.

Many frogs come out to mate spectacularly once a year; and when they're in the throes of mating, there's not much that will make them stop and run away and hide.

So it's relatively easy for researchers to study a site from season to season and get a quick handle on population changes.

(That's not true of all amphibians, of course - the enigmatic being a good counter-example.)

Common_lizardReptiles, on the other hand, don't generally go in for such spectacular seasonal manifestations, and just finding them can be an issue, let alone combing the relatively large patches of land they might inhabit to assess numbers.

Even the UK's enthusiasts have not generated the same amount of data for reptiles as for amphibians, he says.

Whereas the year's first spawning of frogs is anticipated and documented and used as a marker for the arrival of spring, there's nothing comparable with reptiles.

In the developing world, conservation groups are now funding regular research trips aimed at finding new amphibian species - and .

Perhaps something similar is needed now for reptiles.

For a comprehensive picture to emerge, we should look to the global assessment - these are regarded in the field as being just about as definitive as you can get.

But the chances of it arriving any time soon look pretty remote. Simon Stuart, chair of the IUCN , tells me they just don't have the $2-3m needed to do it.

In the meantime, IUCN and the plan to release an analysis of 1,500 species in a few months' time, which they think might provide a more accurate indication of global status than anything we have at present.

Does it - should it - make you feel a little uncomfortable that the world's reptiles might be under threat just as much as amphibians, currently the most threatened group of all - and we just don't know?

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