Snakes in mysterious global decline

Snakes may be declining across the world, according to a global study.

Researchers examined records for 17 snake populations covering eight species over the last few decades, and found most had declined markedly.

For reasons that are not entirely clear, some populations shrank in number abruptly around 1998.

Writing in the journal Biology Letters, the researchers describe the findings as "alarming" but say much more work is needed to understand the causes.

"This is the first time that data has been analysed 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," said project leader Chris Reading.

"It surprised us when we realised what we were looking at," he told BBC News.

"And we don't have a clue what it was about that period of time (around 1998)."

Dr Reading's team at the UK's Centre for Ecology and Hydrology ran the study with institutions in Australia, France, Italy and Nigeria. ...

Populations shrank even in protected areas, suggesting that the progressive loss of habitat for wild animals being seen all over the world is not the only cause.

Similar steep declines observed in frogs and newts in an earlier period were eventually found to be caused by the fungal disease chytridiomycosis.

The year when many of the snake declines began - 1998 - raises the question of whether climatic factors might be involved, as very strong El Nino conditions contributed to making it the hottest year recorded in modern times.

Dr Reading's research group suggests many causes might be involved, and is appealing to other researchers to come forward with any more long-term datasets that might broaden the picture.

"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'," he said. ...

via BBC News - Snakes in mysterious global decline.