Coronella austriaca, also known as the "smooth snake," was one of the species in the study. Image credit: Wikimedia Commons
Conducting a global study of an entire sub-order of species is not a simple proposition. It requires huge amounts of data, conducted by field researches in locations around the world, that spans a decade or more. As a result, such studies are able to provide only a slight indication of trends.
But sometimes, the findings are so consistent, so compelling, that they cannot be ignored.
Vierpa aspis aspis was one of the many species found to be in decline. Image credit: Wikimedia Commons
Such was the case with a recent study of global snake populations. Combing through data on 17 snake populations covering eight species around the world, researchers observed an "alarming" decline in global populations.
Chris Reading, who led the project, explained:
This is the first time that data has been analyzed in this way, and what we've shown is that in different parts of the world we seem to have this steep decline in a short period.
He went on to say that "it surprised us when we realised what we were looking at."
Another species in the study, Python regiusalso showed declines. Image credit: quantumdtell/Flickr
The data sets showed steep declines eight of the 17 populations—some by more than 90 percent. Only one population showed signs of an increasing population.
Declines were observed even in protected areas, indicating that something other than habitat loss may be a driver. Climatic events, the team proposed, could be one reason, though it is impossible to determine without further research.
A similar study of global amphibian populations eventually led researchers to identify a chytridiomycosis epidemic as the major cause of declines of those species.
"The purpose of this paper was to say 'this is what we've found', and to say to other herpetologists 'now go and look at your own data'," Reading explained, ""But I think that with so many populations in different places showing decline, it's more than co-incidence."