Tropical lizards can't take increased heat

Science Daily: From geckos and iguanas to Gila monsters and Komodo dragons, lizards are among the most common reptiles on Earth. They are found on every continent except Antarctica. One even pitches car insurance in TV ads. They seemingly can adapt to a variety of conditions, but are most abundant in the tropics. However, new research that builds on data collected more than three decades ago demonstrates that lizards living in tropical forests in Central and South America and the Caribbean could be in serious peril from rising temperatures associated with climate change.

In fact, those forest lizards appear to tolerate a much narrower range of survivable temperatures than do their relatives at higher latitudes and are actually less tolerant of high temperatures, said Raymond Huey, a University of Washington biology professor. "The least heat-tolerant lizards in the world are found at the lowest latitudes, in the tropical forests. I find that amazing," said Huey, lead author of a paper outlining climate warming's threat to lizards published in the March 4 Proceedings of the Royal Society B. The Royal Society is Great Britain's national academy of science.

It has often been assumed that tropical organisms are much better at dealing with high temperatures than those in colder climates because the lowland tropics are always warm. But that assumption is only true to a point, Huey said, because those in the tropical forest experience a much narrower range of temperatures during the year and are rarely, if ever, exposed to extreme high temperatures….

A komodo dragon, taken by Raul654, Wikimedia Commons, under the terms of the GNU Free Documentation License, Version 1.2