ANiMAL MUNDi: The Arctic Ground Squirrel by Corinna of TheFrogBag

 by Corinna of TheFrogBag

Arctic Ground Squirrel

Imagine sleeping for seven months out of twelve. Sounds like a pretty laid back lifestyle until you remember that you’d have to fit a year’s worth of living into the other five. And that’s just what the arctic ground squirrel (Spermophilus parryii) does. Restricted to the Arctic, its range still encompasses a huge area including parts of Russia, Alaska, and British Columbia. This is a land of extremes though, where any life at all is difficult.

Spermophilus is the largest type of ground squirrel in the world, needing the extra bulk to survive in such a cold environment. Large can be a relative term though. A really big male squirrel may weigh a bit more than 700 grams, or about a pound and a half. Hardly mammoth, but then again they do need to fit into the burrows that they dig above the permafrost line. 

Also called “sik-siks” by the Inuit people because of the calls they make, these squirrels have complex social lives during the warmer months. Males will ferociously defend their territories from other males. Dominate squirrels control intricate tunnel systems beneath the tundra where they live with a harem of females and their offspring. But all is not harmonious among the lady squirrels either. In an area of scarce resources, even nursery space is in short supply and lactating mothers will defend their nests and the surrounding area from all interlopers. 

Given that they have to pack all the important events of their lives into just a few months, perhaps it isn’t surprising that female Arctic ground squirrels have a gestation period that may be as short as three weeks after breeding occurs in the very early spring. Litters usually have about seven pups in them, but sometimes as many as 14 can be born to one mother. That’s a lot of mouths for one harried squirrel to feed, especially since the males don’t participate in parental care at all. 

The young become independent after only a month, but must use the rest of the warm season to gain enough weight to survive the long, cold months ahead. These squirrels are among only a handful of mammals to enter a true hibernation state, allowing their body temperature to drop to as low as 27 degrees Fahrenheit and their heart rate to slow to just one beat per minute. That’s still a lot warmer than the air above their burrows though, thanks to special hibernation chambers they insulate with grass, fur, and moss.

Laid back? Not quite. But their lifestyle does seem to pay off. Unlike most species that have appeared in this column, these guys are listed as a “species of least concern” by the IUCN Red List, meaning that their conservation status is currently seen as “secure.” Way to go, Arctic ground squirrels!