Snakes in mysterious global decline

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

And:

The researchers believe they amassed most, if not all, long-term datasets for this study - although "long-term" in this context means going back more than one decade, in some cases more than two.

Nevertheless, within this relatively short time frame, eight of the 17 populations were seen to fall markedly in size - some by more than 90% - with only one showing any sign of a rise.

And:

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.