Already rather small in stature, salamanders in the Appalachian Mountains (where the amphibian is abundant) are shrinking, phys.org reported. Climate change, according to the study, has something to do with it.
Comparing Appalachian specimens from as far back as 1957, researchers found salamanders were about 8 percent smaller after 1980. The differences were most pronounced among species living in the region's southern territory and at lower elevations, or where conditions have been impacted by climate change the most.
"This is one of the largest and fastest rates of change ever recorded in any animal," Karen R. Lips, an associate professor of biology at the University of Maryland and the study's lead author, said in a statement. "We don't know exactly how or why it's happening, but our data show it is clearly correlated with climate change."
Lips and colleagues aren't exactly sure how salamanders became smaller, but they have some theories. After ruling out fungal disease -- the underlying cause of a species of frogs' size reduction -- they tracked a salamander's daily activity and found they burned 7 to 8 percent more calories than their pre-1980 predecessors (while carrying out the same amount of activity). Thus, salamanders today might not be genetically smaller, but trimmer.
Still, researchers don't have enough data to rule out a genetic change, or the process by which smaller salamanders better suited for survival are naturally selected for over larger versions.
"We don't know if this is a genetic change or a sign that the animals are flexible enough to adjust to new conditions," Lips said. "If these animals are adjust, it gives us hope that some species are going to be able to keep up with climate change."
The shrinking of animals is commonly proposed outcome of climate change, according to the study.
