Snake Awake!

western terrestrial garter snake

Warmer temperatures are bringing old friends wriggling out from under the rocks!  In school programs last week, someone spotted a garter snake on each day!  All the snakes spotted were near their holes, apparently sunning themselves on the rocks and getting ready to begin another active season.
 
So what have these snakes been doing all winter long?  Sleeping?  Not exactly.  Imagine if you decided that you disliked winter and curled up in your bed to sleep the entire season away from November through March.  What would happen?  You would wake up in need of food and water!  No matter how cozy your comforter may feel, humans are not designed to hibernate. 

Animals that hibernate must be specially adapted to do so.  In order to survive for an entire winter without food, they must use very little energy over the entire course of that time.  Mammals tend to build up fat reserves by eating lots in the fall.  This fat helps them survive through the long cold months.   When reptiles like snakes hibernate, they cope with the long period without food by loweing their body temperatures and heart rates.  Hibernating mammals may do this as well.  This is why it is important not to disturb hibernating animals that you may discover during the winter.  Reacting to you and attempts to escape may use up energy that animal needed in order to survive until spring.

Although garter snakes will allow their body temperatures to drop while they hibernate, they still must stay above a certain temperature to survive.  Hiding in a den underground is one way to stay warm.  A den like this is called a hibernaculum.  Another way to stay warm is to share the hibnernaculum with other snakes.  Garter snakes hibernate in aggregate, that means lots of them all together.  Sometimes they will even share a hibernaculum with snakes of a different species! 

In the spring, the snakes will become active once again, venturing outside the hibernaculum and eventually hunting for food and looking for mates. Since they have been hibernating in aggregate, you may see several snakes all close together as they emerge.  So next time you are in the park, keep your eyes open for snakes and other newly active hibernators!