|FEBRUARY 9, 2008—Everyone knows, you feel better if you get a good night’s sleep. For hibernating creatures, it’s crucial to their survival.|
Rising temperatures are waking hibernating critters up early from their winter naps, say researchers at the Rocky Mountain Biological Lab in Crested Butte, Colo., who have been documenting marmot behavior since the 1970s.
When they started looking at marmot hibernation, the creatures rarely woke before the third week of May, but now they rarely sleep past the third week of April.
The latest research adds to a growing body of evidence that shows hibernating species are waking up earlier or not hibernating at all, due to rising temperatures from global climate change.
These changes in hibernation patterns put these species at greater risk of starvation and predation, which could bring them to the brink of extinction, researchers say.
“With respect to the marmots, at least, the evidence is convincing that it is connected to warming temperatures,” David Inouye, a biology professor at the University of Maryland who collaborated with the Rocky Mountain Biological Lab researchers, told National Geographic.
When an animal is hibernating, it relies on fat stores for energy. Hibernation slows the animals’ metabolic rate so it uses the reserves stocked up in summer and fall very slowly. As long as the air is cold, the animal continues to hibernate. As the air warms, the animals’ metabolic rate increases, using fat stores faster and sending a signal to the animal that it’s time to wake up.
Unfortunately, the food sources for hibernating animals aren’t waking up sooner, increasing the risk that early risers will starve.
“Wildflowers still rely on the snowmelt as their cue to come out of their hibernation,” Inouye told National Geographic, and snowmelt still happens much later than the marmots’ April wake-up call.
Without their traditional source of food, marmots have been spotted trying to eat trees.
With snow on the ground covering the vast underground escape routes and hibernators wandering farther and farther from their burrows for food, they become much easier pray for hungry coyotes and wolves.
One of the most astounding findings is that hibernating animals change their wake-up call time based on a change in temperature as small as one degree.
Brown bears in Spain skipped their hibernation last year, according to the country’s Brown Bear Foundation.
“I do think we need to start being very honest about what is going on,” Terry Root, a professor at Stanford University’s Center for Environmental Science and Policy, told National Geographic. “I do think what we will be facing is the extinction of many species.”