23 October 2015
Every autumn I miss the moment when the chipmunks disappear.
For weeks they’re vocal and active while they gather food to store in their underground burrows for the winter. Then one day they stay underground and go to sleep. Days or weeks later it dawns on me, “I haven’t seen a chipmunk in a while.”
Chipmunks (Tamias striatus) are not true hibernators. Instead they go into periodic bouts of torpor in which they lower their body temperature and sleep deeply, then wake up to eat and defecate. On warm winter days we see them out foraging.
Ironically an unusually warm winter is fatal to chipmunks. A 2008 study by Craig Frank at Fordham University found that chipmunks are less likely to enter torpor when the weather’s warm. Those who do enter torpor have an 90% winter survival rate. If they stay awake in warm weather, they die. (90% mortality. Yow! Climate change is bad for chipmunks. Click here to read more.)
Some day soon the chipmunks will go underground, enter torpor, and not resurface until a warm winter day. Will we notice their absence?
Here today, asleep tomorrow.
(photo by Chuck Tague)
We keep our bird feeders stocked year round and we have greedy chipmunks almost all year. They are absent only when it is really cold or the snow cover is deep. I suspect that if they have a reliable food source they are less likely to stay underground. I have also read that bear’s bodies measure calories in and calories out to determine when to hibernate.
Is it true that there are no chipmunks in Raleigh, NC? My daughter lives there and that’s what she’s heard. Thanks! Cheryl
Cheryl, there are chipmunks in the state of North Carolina. Here’s the range map. I can’t tell whether Raleigh is inside or outside of the zone: http://www.basic.ncsu.edu/ncgap/sppreport/amafb02230.html
Why do chipmunks cover up their holes and seem to disappear. Do they make their homes in other places when they cover up their old hole.