NORWICH BULLETIN (Connecticut) 05 August 07 Cold puts snakes in hibernation (Charlene Perkins Cutler)
This is New England and that means we can expect hot, humid 90 degree weather one week, followed by some incredibly abnormal cold spell the next. I like variety, so that's fine with me. However, I began to wonder the other day how drastic changes in weather from summer to winter affect wildlife, particularly snakes.
I have never feigned a fondness for the reptiles, a point made clear in previous columns. After all, they go out of their way to startle me and generally gross me out with their unnerving ability to move in ways impossible for humans. I can honestly say I am fonder of them in the winter than the summer. Actually their absence makes me very happy.
But I do know snakes are an important part of our ecosystem and so I began to feel culpable reveling in their absence. Where do they go in the frigid depths of January? A combination of guilty conscience and curiosity drove me to the good old Encyclopedia Britannica. What I learned was enlightening, and a bit disconcerting.
Snakes spend the better part of their lives coping with changes and extremes in the environment.
The creatures that adapt easily to their surroundings, such as those living in the tropics, face increased competition from other thriving species, as well as increased numbers of predators.
While something such as Vipera berus, a snake living within the arctic circle in Europe, is virtually unchallenged in this environmental niche, it faces monumental challenges in surviving freezing and dehydration.
The Last Green Valley, being a temperate region, also offers a survival challenge to snakes. They enter a period of hibernation when they must seek out a place where they can be completely inactive and nonreactive. They must remove themselves from any potential danger to compensate for their inability to respond to it.
In addition to extreme low temperature, the other danger of winter months comes from low humidity -- not a friendly element for the reptiles.
Ideal resting places to compensate for these unfriendly elements are not easily found. Many snakes return to the same hibernation dens each year, and several species will share the same den -- veritable snake condos.
It is interesting biologists have found snakes don't remember the location from year to year, but follow the scent trail left by those that have gone before them. Evidently, the scent trail grows stronger as successive snakes arrive from greater and greater distances. Once the snakes enter the den, certain physiological changes take place. As the body cools, heartbeat and respiration nearly stop. There is no muscular activity and little digestion. No alarm system is activated to stir the reptile into a response if some level of tolerance is passed. So, if it gets too cold or a predator comes by, the snake dies.
At the end of the cold season, the snake must rely on changes in the environment to bring it back to activity -- it can not rouse itself by some internal biological clock.
I wish all our milk snakes, garter snakes, black snakes and others the best of good fortune during the winter months. I really never have wanted to see them decimated, and hope they all survive.
But I can't wait for winter when the snakes no longer put themselves in my path. And I'm sure they would prefer to be somewhere scream-free.
http://www.norwichbulletin.com/apps/pbcs.dll/article?AID=/20070805/COLUMNISTS10/708050312/1024/LIFESTYLE
