- June 12, 2018 - Biodôme : Animal portrait
Were you aware that the name of the chipmunk genus is Tamias, from the Greek for treasurer or steward? In Québec the eastern chipmunk is known as a “suisse” because of the similarities of its stripes to those on the uniforms of the Swiss Guard responsible for the security of the Pope at the Vatican.
Choosing the right neighborhood
For the chipmunk, a secure neighborhood offering local services comes down to an area with a radius of roughly 30 meters, and satisfying various criteria. First, the habitat must contain enough leaf and branch debris to effectively conceal the entrance to the burrow, but there should also be hiding places and perches where the chipmunk can take refuge. In addition, the presence of enough trees producing rich nuts and seeds guarantees reserves for the winter season.
Making the most of its movements
Trees normally produce their seeds over a short period, but in impressive quantities. To take advantage of this period of abundance, there’s no point in venturing off on roundtrips that bring back just a single seed at a time. According to one study, chipmunks can stockpile no fewer than 13 plum pits or 32 beech nuts in their elastic cheek pouches. That’s a little as if, proportionately, we were able to store 13 mango pits at a time in our cheeks.
A well-structured pantry
Whereas certain porcupines, for example, sleep on a bed of droppings during the winter, the chipmunk isn’t inclined to do his business in the “bedroom.” Underground, at a depth of around 75 centimeters, the chipmunk lays out a network of galleries and tunnels in which each room has its own function. A big one for sleeping in, some small ones for the stash of winter stores, and generally a little corner in the back for a toilet. The overall space must be big enough to accommodate seven liters of seeds.
An atypical hibernation
Unlike some hibernators – the groundhog, say – the chipmunk is considered to be a pseudo hibernator. What happens is, it regularly comes out of its state of torpor in order to eat. In other words, it differs from true hibernators in the fact that, to survive the winter, it doesn’t depend on its reserves of fat but rather on the stores of food it’s accumulated. Studies carried out at McGill University have demonstrated that the chipmunk comes out of its torpor more often if it has a significant quantity of food available. Furthermore, if the temperature in the burrow is very low, the chipmunk will wake up less often and for shorter periods of time. The chipmunk therefore has every interest in choosing the right spot for setting up a burrow that will keep it as warm as possible and provide space for its supplies – so it doesn’t have to subject its body too often to the rigors of winter.
- Banfield, A.W.F. 1976. The Mammals of Canada, 2nd edition, University of Toronto Press
- Landry-Cuerrier, M. 2008. From habitat to energetics: eastern chipmunk burrow microhabitat selection and fine-scale variation in winter torpor expression. Department of Natural Resource Science. McGill University, Macdonald Campus, Montréal, Québec