Global Warming May Change Hibernation Patterns; Csu Research Focusing on Genetic Vs. Environmental Factors

Changes in snowfall, summer precipitation and ambient temperatures around the globe attributed to global warming could effect the survival of hibernating species such as groundhogs, marmots and ground squirrels, according to Colorado State University Professor Greg Florant.

Florant, a professor of biology at CSU, has teamed with Professor Stam Zervanos at Penn State University to determine whether animal torpor patterns are genetic or can be manipulated by environmental temperatures. Torpor is a period of reduced physical activity, body temperature and metabolism.

The researchers collected groundhogs from areas in Maine, Pennsylvania and South Carolina. The specimens were brought to Florant’s lab at CSU for "common garden" studies and are being kept at 41 degrees Fahrenheit to determine if there are any differences in behavior, such as the animals from one area awaking earlier than others do. Generally, animals in colder climates spend more time in hibernation than their counterparts in regions further south.

"We do know that there are definite changes in torpor patterns among the animals in their natural environments," Florant said. "The question now is: Will we see these changes in the lab?"

Hibernating animals such as groundhogs traditionally are seen as predictors of weather, Florant said. However, these animals can teach researchers more about the complex behavior of hypometabolism – a regulated decrease in metabolic rate – in which animals can turn off their appetites and slow their breathing to a point that would be lethal to other animals. Florant investigates how changes in metabolism during hibernation relate to the regulation of food intake and obesity.

The effect of climate change on hibernating animals already can be seen. Yellow-bellied marmots are emerging 38 days earlier than 23 years ago, apparently in response to warmer spring temperatures at the Rocky Mountain Biological Laboratory near Crested Butte, according to the research of University of Maryland Professor Dave Inouye.

The primary concern with increases in global temperatures in regard to hibernating animals is the effect those warmer temperatures will have on the amount of time spent hibernating. If animals were to increase their metabolism before plants have begun to sprout, they could die from starvation.