All animals struggle to find adequate food in cold, dark winters. Around 12,000 years ago, our ancestors started planting wild varieties of peas, lentils, and barley, along with figuring out that herding animals for food and warm clothes was much more dependable than hunting or foraging. So, we humans rely on cultural solutions like inventions and language to solve the hard nut of survival, rather than genetic evolution.
Right now, many are shivering under a blanket of historic snow and ice without power. Texas must seem like a Titanic of sorts. Few people are self-sustaining, rather our lives depend on the infrastructure of post-industrial civilization. The Texas model is one of unregulated fossil fuel corporations running the show with no connection to the national grid. This crisis vividly underscores the vulnerabilities of that.
Many animals use hibernation as their way to survive without migrating to warmer climes. They turn down their metabolisms to save energy. Some in hot climes undergo a form of hibernation called aestivation, which works in a similar way and enables them to endure extreme heat or lack of food.
Hibernating is much more profound than simply sleeping. Depending on the species, it can vary from long, deep unconsciousness to short spells of inactivity. Small mammals, such as chipmunks and hedgehogs, hibernate – plus many insects like ladybugs, amphibians and reptiles. Bears have “dormancy light”, where they are groggy, but easily roused in their dens.
To prepare for winter, mammals feed heavily in summer and autumn, storing fat to see them thru the lean months. During hibernation, body temperature and breathing slows. A bat’s heart rate can fall from 400 to 11 beats per minute. Some cold-blooded animals produce natural antifreezes to avoid being frozen solid.
Hibernation is intriguing enough, but some animals actually have brief bouts of suspended animation, called a torpor, usually lasting less than a day. Hummingbirds and bats can go into torpor every day.
For my hibernating residents, I leave some wild areas in my garden with soggy leaves, fallen branches, and downy moss. I put up a simple wooden “bee hotel” with holes for nesting solitary bees, and may add a bat nesting box before long. In the summer at dusk, swooping and careening brown bats vacuum up the gnats, and I really should return the favor.