May 14, 2010
How much heat can a lizard endure? That sounds like the question a fourth-grader might ask (and then try to answer, tragically, by adding a couple more heat lamps to his pet lizard’s tank), but it’s a real concern in this era of climate change. Lizards are cold-blooded creatures and while they need heat to keep warm, too much can kill them. And a new study, published today in Science, predicts that a full 20 percent of lizard species worldwide will become extinct by 2080 due to the hotter temperatures brought about by climate change.
The story starts in Mexico, where 12 percent of lizard species have gone extinct since 1975. The researchers monitored temperatures at sites where lizards currently live and where they had disappeared. Regions lacking lizards had higher daytime temperatures. Because lizards can’t forage when it’s too hot, the hotter days would have limited their ability to find enough food.
When the analysis was applied to other parts of the world, the pattern of increased daytime temperatures predicted areas where lizards had already gone extinct. And extrapolated to the entire world 70 years in the future, at least 20 percent of lizards species (and 39 percent of local populations) may disappear.
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