Wildlife Wednesday -- Hibernation Zone

By Andy Ames

First came the chipmunks and then the Wyoming ground Squirrels. More recently, marmots and Golden-mantled ground squirrels have emerged from hibernation. Rodents are known for their ever growing incisors, or front teeth. Throughout their lives dentin is added on a circadian, or daily, basis to the root of the tooth. These teeth are kept in check by the wear of chewing. During hibernation, however, this tooth growth slows as the body temperature of the rodent drops. This creates a “hibernation zone” on the tooth marking the time of hibernation. Theoretically scientists are able to measure the length and timing of an individuals hibernation. Over time that “hibernation zone” will be pushed toward the tip of the tooth as new tooth material is added, eventually being lost to wear.