I read that in the potato famine in Ireland one of the problems is that people were not used to working in winter, but sat inside their big fireplaces to keep warm..when the famine and work relief (?) came, they had no clothes really for winter, and would have pawned them anyway, and they had no experience I guess of working in the winter..this is what the article said and I think it was a history by a relief person at the time...plus there were awful snows etc. that were not usual...plus of course they were starving..so that contributed to the death and misery of the place. Not hibernation per se but perhaps a way of getting through the winter. mg