Early Spring: Marmot’s Choice

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ambience: Marmot vocalizations

The groundhog’s decision to leave or return to its burrow is usually regarded as folklore, but there may well be a scientific basis for the story. I’m Jim Metzner, and this is the Pulse of the Planet. Marmots are cousins of woodchucks and groundhogs, and every year they come out of hibernation in the early spring. You can hear them vocalizing in the background.

“Marmots typically burrow through the last few feet of snow on the ground, stick their heads out and appear to then decide, based on the temperature, whether they should go back down and reenter hibernation for another few weeks or to stay out.”

David Inouye is director of the graduate program of conservation biology at the University of Maryland. He tells us that because of global warming, marmots up in the Rocky Mountains have been emerging from their burrows earlier in the year than they have in the past.

“Marmots are now emerging thirty-eight days earlier than they did twenty-three years ago. We believe that this is in response to the warming in temperature. Because the temperatures in April have been warming up, they seem to be confused, and they’re now staying out in April earlier and earlier, even though there is still as much as five or six feet of snow on the ground.”

Now, whether the marmot decides to return to hibernation or not could well mean the difference between life and death.

“They are now emerging over a month earlier than they used to, and they are having to spend most of that time waiting for the snow to melt. These animals have not eaten for eight months and winter starvation is one of the major causes of mortality in marmots. So, if this interval between the time they emerge and the time there is something green for them to eat keeps increasing, they are going to run even more risk of starvation in the future. In the long term, we would expect an evolutionary response, and the smart marmots are going to be the ones that learn to adjust to this new climate regime. But over the short term, it may be tough for marmots.”

Pulse of the Planet is presented by the National Science Foundation. I’m Jim Metzner.

music

Early Spring: Marmot's Choice

Marmots risk starvation because of misleading cues that spring has arrived in the Rocky Mountains.
Air Date:04/09/2007
Scientist:
Transcript:


music
ambience: Marmot vocalizations

The groundhog's decision to leave or return to its burrow is usually regarded as folklore, but there may well be a scientific basis for the story. I'm Jim Metzner, and this is the Pulse of the Planet. Marmots are cousins of woodchucks and groundhogs, and every year they come out of hibernation in the early spring. You can hear them vocalizing in the background.

"Marmots typically burrow through the last few feet of snow on the ground, stick their heads out and appear to then decide, based on the temperature, whether they should go back down and reenter hibernation for another few weeks or to stay out."

David Inouye is director of the graduate program of conservation biology at the University of Maryland. He tells us that because of global warming, marmots up in the Rocky Mountains have been emerging from their burrows earlier in the year than they have in the past.

"Marmots are now emerging thirty-eight days earlier than they did twenty-three years ago. We believe that this is in response to the warming in temperature. Because the temperatures in April have been warming up, they seem to be confused, and they’re now staying out in April earlier and earlier, even though there is still as much as five or six feet of snow on the ground."

Now, whether the marmot decides to return to hibernation or not could well mean the difference between life and death.

"They are now emerging over a month earlier than they used to, and they are having to spend most of that time waiting for the snow to melt. These animals have not eaten for eight months and winter starvation is one of the major causes of mortality in marmots. So, if this interval between the time they emerge and the time there is something green for them to eat keeps increasing, they are going to run even more risk of starvation in the future. In the long term, we would expect an evolutionary response, and the smart marmots are going to be the ones that learn to adjust to this new climate regime. But over the short term, it may be tough for marmots."

Pulse of the Planet is presented by the National Science Foundation. I'm Jim Metzner.

music