PROVIDENCE, R.I. [Brown University] Species' ability to overcome adversity goes beyond Darwin's survival of the fittest. Climate change has made sure of that. In a new study based on simulations examining species and their projected range, researchers at Brown University argue that whether an animal can make it to a final, climate-friendly destination isn't a simple matter of being able to travel a long way. It's the extent to which the creatures can withstand rapid fluctuations in climate along the way that will determine whether they complete the journey.
In a paper in Ecology Letters, Regan Early and Dov Sax examined the projected "climate paths" of 15 amphibians in the western United States to the year 2100. Using well-known climate forecasting models to extrapolate decades-long changes for specific locations, the researchers determined that more than half of the species would become extinct or endangered. The reason, they find, is that the climate undergoes swings in temperature that can trap species at different points in their travels. It's the severity or duration of those climate swings, coupled with the given creature's persistence, that determines their fate.
"Our work shows that it's not just how fast you disperse, but also your ability to tolerate unfavorable climate for decadal periods that will limit the ability of many species to shift their ranges," said Sax, assistant professor of biology in the Department of Ecology and Evolutionary Biology. "As a consequence, many species that aren't currently of conservation concern are likely to become endangered by the end of the century."
The researchers chose to study frogs, salamanders, and toads because their living areas are known and their susceptibility to temperature changes has been well studied. Based on that information, they modeled the migratory paths for each creature, estimating their travels to be about 15 miles per decade. The climate models showed fl
|Contact: Richard Lewis|