Oct 28 2009
There’s not much time left to prepare for winter, especially if you’re a chipmunk.
Eastern Chipmunks don’t hibernate and they don’t even fatten up in autumn like groundhogs. Instead they stash a winter’s worth of food in their underground burrows where they live from late October to early March (in Pennsylvania) in periodic bouts of torpor.
Torpor is a short period of lowered body temperature and metabolism which conserves energy when it’s cold. For chipmunks the length of torpor is highly variable. They wake up throughout the winter to eat and even come out to forage if the weather’s nice.
Busy, busy, busy! The chipmunks haven’t disappeared underground in the Pittsburgh area yet but their deadline is fast approaching. To expedite their task they can pack up to 32 beech nuts in their cheeks before heading home. Once there, they store the food in various chambers in their elaborate burrows which extend as much as 33 feet long and three feet below the surface. Quite a palace.
I can imagine a chipmunk returning home at this time of year and inspecting the cupboard. Do I have enough food yet? Is the weather still good enough to go out and get more? Is it time to stay home and sleep?
In the next week or two a cold front will come through, the weather will turn nasty and the chipmunks will pack it in. Then we’ll have to wait for a sunny winter day to see them again.
(photo by Brian Herman)