Arctic Ground Squirrel Fun Facts

Did you know ...

... that the arctic ground squirrel was named "tsik-tsik" by the Inupiat Eskimos on account of a call this little rodent makes when it is alarmed?

Tsik-tsiks are found in both arctic and alpine tundra. They fatten themselves on seeds, mushrooms and berries—almost doubling their body weight over the summer—in preparation for fall hibernation. Although they insulate their winter burrows with grasses and block the entrances with dirt, winter temperatures inside the burrows still fall well below 0° F.

During hibernation, the body temperature of the arctic ground squirrel drops from 98.6° F to 26.4° F—that's below the freezing point of water and is the lowest known body temperature of any living mammal. Most mammals, including people, would be frozen solid at that body temperature! Scientists aren't sure just how these diminutive rodents do it, but they apparently have developed a unique mechanism that allows their body fluids to become supercooled—to fall below the freezing point without crystallizing into ice and damaging cell tissue.

Periodically throughout the winter, the tsik-tsik will rouse itself, briefly raising its body temperature more than 70° F in four hours, before going back into hibernation. Not until late March or early April does the arctic ground squirrel finally emerge from its winter den to the light of another spring and six months of intense activity.