Study noticed an 8 percent decline in salamander size from 1980 to 2012.
North American salamanders residing in some of the most pristine salamander habitats are shrinking in size due to climate change, according to a new study published in the journal Global Change Biology. According to the study, as salamander habitats get warmer and drier, the amphibians must burn more energy in order to survive, resulting in their smaller sizes.
Researchers with the University of Maryland, University of Alabama, Clemson University and Iowa State University examined museum specimens of the genus Plethodon that were collected from the Appalachian Mountains from 1957 to 2007 and compared them with the same 14 species collected from the same sites in 2011 -2012. The researchers said the amphibians that were studied from the year 1980 to 2012 were approximately 8 percent smaller, on average that those collected prior to 1980. The most extreme changes occurred in the Southern Appalachian Mountains at low elevations, areas in which weather records show have dried out and become warmer than other areas in the region.
"This is one of the largest and fastest rates of change ever recorded in any animal," said Karen R. Lips, an associate professor of biology at the University of Maryland and the study's senior author. "We don't know exactly how or why it's happening, but our data show it is clearly correlated with climate change."
Lips and her colleagues began the study after following the work of University of Maryland Prof. Emeritus Richard Highton who started collecting the amphibians in 1957 and preserved them in jars at the Smithsonian Institution's Museum Service Center in Suitland, MD.
Highton's record showed a marked decline in the populations of the animals in the 1980s, which Lips initially thought was related to a fungal disease that devastated frog populations that she was studying in Central America. In 2011-2012, students at the University of Maryland, under the guidance of Lips, collected, measured, and collected DNA samples of the salamanders and found no evidence of the fungal disease. However, Lips noticed a drastic change in size of the older specimens compared to those of today. Their study indicated that between the years 1957 and 2012, six species of salamander native to the Appalachian Mountain range shrunk in size while one species grew slightly larger. They noted that each successive generation was 1 percent smaller than the previous generation.
"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[ing], it gives us hope that some species are going to be able to keep up with climate change."