|MadSci Network: Environment|
This is quite a difficult question to answer. Several of the smaller rattlesnake species penetrate territorially into Canada, but the tundra officially starts around Hudson Bay. Very few reptiles can survive at the average annual tundra temperature of 5o Centigrade. Their only hope is to survive the winter deep in vegetation or in the ground, which may have permafrost.
Personally, I believe the rattlesnake is less adapted than some other snakes for surviving these conditions. If it were to adapt, it would change its behaviour to a shrub habitat, living in microhabitats that used sunny south facing locations in the summer and provided lined mouse holes or similar cosy places for the long hibernation period. I would expect breeding to be delayed of course and egg laying to be in mid-summer, with few of the young surviving in their tiny exposed state unless they found a heat source.
Perhaps the answer for you lies in the use by reptiles of human resources that are warmer than the environment. People are composting more and heated buildings may have spaces for small snakes to reach in order to hibernate successfully.
Global warming means that some areas are experiencing their highest temperatures in centuries, so we can expect snake territory to increase. Southern Ontario has the biggest snake population near to tundra areas, so watch the local news for snake expansion! My references for you would be to watch Canadian news items that report snakes (of any kind) that have been found around schools, hospitals, gardens or sewage plants. That Iím afraid is the best advice available.
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