Wild salamanders in North America are shrinking as their habitats grow warmer and drier, says new research from Clemson University.

Data published in the journal Global Change Biology assert climatic changes in the Appalachian Mountains -- long considered ideal for salamanders to thrive -- have forced the four-toed amphibians to expend more of their bodies' fuel on simply surviving and apparently less on growing.

A scientific team from the South Carolina-based university examined museum specimens caught in the Appalachians from 1957 to 2007 and wild salamanders measured at the same sites between 2011-2012.

The salamanders studied from 1980 onward were an average 8 percent smaller than their their counterparts decades before.

Those size differences, the study said, were most notable in the Southern Appalachians and lower elevations, regions where the climate has warmed and dried out the most, according detailed weather recordings.

"One of the stresses that warmer climates will impose on many organisms is warmer body temperatures," lead researcher Michael W. Sears, from Clemson's biological sciences department, explained in a news release. "These warmer body temperatures cause animals to burn more energy while performing their normal activities. All else being equal, this means that there is less energy for growth."

Sears used a computer program to create an artificial salamander, with which he was able to calculate the daily activity of a typical salamander and the number of calories the critter burned.

Then, using detailed weather observations taken at the study sites, he was able to approximate the behavior of individual salamanders during their lifetimes, down to the minute, based on the specific climate conditions of their home locations.

In fact, the computer simulation suggested modern salamanders are just as active as their ancestors had been.

"Ectothermic organisms, such as salamanders, cannot produce their own body heat," Sears said. "Their metabolism speeds up as temperatures rise, causing a salamander to burn seven to eight percent more energy in order to maintain the same activity as their forebears."

While the changing body size of the region's salamanders is one of the largest and fastest rates of change ever observed in any animal, the data collected for the study clearly shows those changes are correlated with climate change, said Karen R. Lips, associate professor at the University of Maryland's department of biology and a co-author of the paper.

"We do not know if decreased body size is a genetic change or a sign that the animals are flexible enough to adjust to new conditions," said Lips. "If these animals are adjusting, it gives us hope that some species are going to be able to keep up with climate change."