Wild salamanders that live in the Appalachian Mountains are shrinking because they must burn more energy as the local climate gets hotter and drier, according to a new study.

 

Researchers found that the salamanders they collected between 1980 and 2012 were 8 percent smaller than those collected in earlier decades, starting in 1957. The findings confirm predictions that some species will shrink in response to climate change. The climate where the salamanders live has gotten warmer and drier, researchers said.

 

The researchers' interest in salamander size was sparked by a decline in salamander populations in the Appalachians since the 1980s.

 

Between summer 2011 and spring 2012 researchers collected and measured salamanders in Maryland, Virginia, West Virginia, North Carolina and Tennessee, and also took DNA samples. The wild salamanders were compared to specimens previously collected by Richard Highton, a University of Maryland biologist, who began collecting in 1957.

 

The team found no evidence of fungal disease in the 16 salamander species they examined. However, they did find that six salamander species grew notably smaller and just one species got a bit larger since 1957. The animals shrank 1 percent per generation on average.

 

In order to examine the changing climate's effect on the salamanders' activity, the researchers created a computer model of an artificial salamander and combined it with weather data. They found that modern salamanders were as active as their ancestors, but, as cold-blooded animals, they had to burn 7 to 8 percent more energy to maintain the same level of activity. As they get smaller, that means they can't quite reproduce as much and when it comes to amphibians, the bigger they are, the more they can reproduce.

 

The findings were published March 25 in the journal Global Change Biology.