If average temperatures rise as projected in eastern North America in coming decades, at least one widespread amphibian species likely will be unable to adjust, and its range may shift northward, according to a new study led by Penn State scientists. In a novel experiment, researchers devised a method to measure the metabolic rate of red-backed salamanders from different regions exposed to warmer temperatures—analyzing how much more energy the small, hardy woodland amphibians would expend to survive in the forests they now inhabit from Quebec south to North Carolina, and west to Missouri and Minnesota.