Salamanders, scientists believe, are shrinking to adapt to the warmer environment created through global warming. A new study found that Appalachian salamanders are getting smaller in size and it may be due to drier and warmer conditions. Becoming smaller has its evolutionary benefits for the amphibian.
One of the researchers involved in the study said that warmer body temperatures are one part of the issue here for the salamanders in North America. Warmer body temperatures mean that animals burn through more of their energy. The bigger the animal, the more energy are needed for survival.
The study found that the wild salamanders have been getting smaller since 1957. They analyzed data from then until 2007. They looked at museum specimens throughout that time. After that, the researchers studied the salamanders from the same Appalachian site in 2011 and 2012 to make more measurements. The data seemed conclusive that the salamanders are actually shrinking.
The researchers also used a computer model to create a salamander. They were interested in how the salamander's daily routines and calorie burning would be impacted by the warmer body temperature. Researchers also believe that the salamander might have a higher propensity toward shrinking because they are ectothermic. In other words, they don't produce their own body heat. Their metabolism therefore speeds up so they burn even more calories.
The North American wild salamanders are cold-blooded creatures and they don't have enough energy left to grow as they are burning more calories than they once did, due to the increase in temperature in the Appalachians. Scientists want to explore next the difference between the shrinking salamanders and the ones that are disappearing from Earth altogether, reports suggest.
The study was published in the journal Global Change Biology. The wild salamanders found to be shrinking were taken from the states of Tennessee, North Carolina, West Virginia, Virginia and Maryland, reportedly. Less than half of the species they studied were shown to be shrinking, however, and one species even showed to be growing.
Kenneth Dodd, associate professor of Wildlife Ecology and Conservation at the University of Florida said the data could be implicating other environmental factors as well. At least six species studied at the ranges where the researchers explored showed to be shrinking, while eight had no change.