Salamanders are shrinking as their mountain habitats get warmer, drier
Photo: Nicholas M. Caruso
Some of the best habitats in North America for salamanders are showing strain from climate change, becoming warmer and drier as global temperatures and weather patterns shift. This means the salamanders living there, which rely on cool, moist forests, are also experiencing changes. Forced to burn more energy to deal with the changing clime, the salamanders are getting smaller in average size.
Research from University of Maryland, published yesterday in the journal Global Change Biology, shows that the predictions by scientists that some animals will deal with climate chance by getting smaller is panning out among salamanders. The research team "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% 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," reports UMD.
For example, an Appalachian species that has become significantly smaller over the last few decades is the Northern gray-cheeked salamander, pictured above. But this is just one of several species, and the rate of change is startling. Where the climate is getting warmer and dryer, salamanders are having to burn around 7-8 percent more energy than their forebearers to stay equally as active, and it results in each generation of salamanders being about 1 percent smaller than their parents.
“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 ... We don’t know if this is a genetic change or a sign that the animals are flexible enough to adjust to new conditions. If these animals are adjusting, it gives us hope that some species are going to be able to keep up with climate change.”
That hope is key, since salamanders and other amphibians, most notably frog species, are facing serious challenges to surviving in rapidly changing habitats. Lips notes that the resulting changes could mean that the salamanders spend more time foraging for food and less time looking for mates, which may mean having fewer young and being more vulnerable to predators. But whether the salamanders successfully adapt or decline is yet to be discovered.
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