Researchers in the journal Biology Letters say that snakes across the world may be experiencing a marked decline.

According to a BBC article, researchers examined records for 17 snake populations covering eight species, and found that most had declined. Some shrank in number abruptly around 1998.

“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,” said project leader Chris Reading to the BBC.

From the BBC:

Monitoring snake populations means marking the individuals in some way — typically by snipping a pattern into their scales, or implanting a microchip.

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.

Researchers found that eight of the 17 populations were falling in size, some by more than 90 percent. Those species in decline include the asp and the smooth snake from Europe, the Gabon viper and rhinoceros viper of West Africa, and the royal python.

Researchers found that populations fell even in protected areas.

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