We’ve already taken a look at bears and how they spend their winter months. Small mammals also spend the winter in Alberta and survive by doing one of three things:
- hibernating for the winter (deep hibernation);
- going into torpor (light hibernation) for short periods and still needing to look for food; or
- staying active all winter.
Ground squirrels, such as the Richardson’s, Columbian ground squirrel and hoary marmots, hibernate in their burrows– depending on the age and gender, hibernation lasts for 5-9 months. Their body temperature drops almost as low as ambient (so they are deep hibernators).
Deer mice may go into torpor for part of the day, usually snuggled up to other mice for warmth, they still need to look for food throughout the winter months. Mice and other small mammals, like voles, make tunnels under the snow, which is why you don’t see them very much in the winter.
Ord’s kangaroo rat, an endangered species, is a small mammal living in the dry desert area of southern Alberta. Like other rodents, they head underground to avoid the cold winter months. However, they do not hibernate like ground squirrels. They survive by going into daily torpor bouts and waking up at night to feed from their food cache. Therefore, it’s really important they gather enough food during the summer to last all winter long. They spend the winter alone in their burrows.
Alberta’s long cold winter is tough on kangaroo rats and many of them do not survive the winter, dying from starvation or hypothermia. In the spring when the weather is warm and the snow is gone, kangaroo rats emerge from their burrows to find mates and start collecting food for next winter.
Some small mammals, like the red squirrel and pika, get through winter without hibernating at all – they are able to survive by caching food.
Most people have seen red squirrels carrying or burying food at the end of the summer –they will even place mushrooms on branches to dry out before hiding them!
So now that we know who’s sleeping, who’s napping and who is braving the elements, the question that remains is when will we be seeing our hibernating bats, amphibians, reptiles, bears and other mammals again? Our final part of this series will look at just that.