Tuesday, June 10, 2008

Hastening extinction in Madagascar's reptiles and amphibians

Science Daily: New research from the American Museum of Natural History provides the first detailed study showing that global warming forces species to move up tropical mountains as their habitats shift upward. Christopher Raxworthy, Associate Curator in the Department of Herpetology, predicts that at least three species of amphibians and reptiles found in Madagascar's mountainous north could go extinct between 2050 and 2100 because of habitat loss associated with rising global temperatures. These species, currently moving upslope to compensate for habitat loss at lower and warmer altitudes, will eventually have no place to move to.

"Two things together--highly localized distribution close to the very highest summits, and the magnitude of these upslope shifts in response to ongoing warming--make a poisonous cocktail for extinction," said Raxworthy. In a paper recently published in Global Change Biology, Raxworthy and colleagues found overall trends for elevation changes among 30 species of amphibians and reptiles.

Uphill movement is a predicted response to increased temperatures, and other studies, including that of J. Alan Pounds in Costa Rica, have provided some empirical evidence of how tropical animals respond to climate change. Raxworthy's research, however, is distinguished by the number and diversity of species, the demonstrated meteorological changes over the same time period, the relatively large shifts in elevation, and the broader assessment of extinction vulnerability for tropical montane communities. Currently, there is also a dearth of information available concerning climate impacts on biodiversity for tropical regions….

Isalo National Park in Madagascar, shot by Bernard Gagnon, Wikimedia Commons, under the terms of the GNU Free Documentation license, Version 1.2

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