Wild salamanders living in some of North America’s best salamander habitat are getting smaller as their surroundings get warmer and drier, forcing them to burn more energy in a changing climate, according to research published in journal Global Change Biology.
Widespread Rapid Reductions in Body Size of Adult Salamanders in Response to Climate Change examined museum specimens caught in the Appalachian Mountains from 1957 to 2007 and wild salamanders measured at the same sites in 2011-2012. The salamanders studied from 1980 onward were, on average, 8 percent smaller than their counterparts from earlier decades. The changes were most marked in the Southern Appalachians and at low elevations – settings where detailed weather records showed the climate has warmed and dried out most.
Between 1957 and 2012, six salamander species got significantly smaller, while only one got slightly larger. On average, each generation was one percent smaller than its parents’ generation, the researchers found.
The researchers compared changes in body size to the animals’ location and their sites’ elevation, temperature and rainfall. They found the salamanders shrank the most at southerly sites, where temperatures rose and rainfall decreased over the 55-year study.
Karen R. Lips, an associate professor of biology at the University of Maryland and the study’s senior author, said the data represent one of the “largest and fastest” rates of change ever recorded in any animal. Researchers don’t know exactly how or why it’s happening, but the data show it is clearly correlated with climate change, she added. And it’s happening at a time when salamanders and other amphibians are in distress, with some species going extinct and others dwindling in number, according to Lips.
Lips said that the research team was unable to confirm if it was a genetic change or a sign that the animals are flexible enough to adjust to new conditions. If these animals are adjusting, it gives hope that some species are going to be able to keep up with, and adapt to, climate change, she added.