March 2025  by Ranger Eric Whiteside

Surviving Winter 

To say that I prefer warm weather might be an understatement. I spend the winter months daydreaming about the 100-degree summer days buried under a mountain of woolen things: blankets, socks, sweaters, and beanies. There is a constant rotation of hot tea and microwaveable heat packs, a never-ending battle against the ever-encroaching cold at our house. On particularly cold and frosty winter mornings, as I lament getting out of my cozy, warm bed, I try to remind myself how lucky I am to have a roof over my head! Every winter, I am in awe of the resilience of all the animals who survive winter without turning on the heater!

Portable Warmth 

One summer, as we started to prepare Camp Shelly, LARPD's campground in South Lake Tahoe, for its long winter hibernation, I watched a Golden-Mantled Ground Squirrel start to make some preparations for the winter. A friend who visited over the fourth of July had left me with one of those classic red and white checkered picnic tablecloths. At first, it was cheesy, but I soon became attached to the aesthetic and was reluctant to finally take it off as we slowly packed the campground up for the summer.

One day, I noticed a chunk missing from one of the corners, but I didn't think much of it; I knew I soon had to take it off and toss it in the trash. Later that afternoon, I caught a glimpse of the culprit - a Golden-Mantled Ground Squirrel who was actively tearing open the plastic outer liner of the cloth, revealing the puffy faux-cotton innards which he was frantically shoving into his mouth until he could fit no more, then dashing off into the forest.

The tablecloth saw a lot of meals over the summer and still held onto some tasty, crusty crumbs. But it still seemed odd. And sure enough, here it was again, tearing the plastic cloth and stuffing its face. What was it doing? I was intent on figuring it out! As I moved closer, it popped its head up, saw me, and bolted preemptively back into the trees. I tried to follow it, but it was much too fast. I wandered a bit in the direction where I had seen it last, guessing what its intentions were with my tablecloth. As soon as I saw it, I laughed out loud. It was just one of a dozen other holes in the ground, but this was my picnic bandit's hole because it was overflowing with bits of a red and white plastic tablecloth. 

Typically, rodents in the Sierras would gather whatever natural materials they could find to insulate their dens for the coming cold months, but this one had certainly hit the jackpot. No beds of pokey pine needles or decaying leaves for this squirrel - if winter is going to trap it underground for months, it might as well do it in a cozy style, right? 

Hunker down underground  

Our resident native squirrel in Sycamore Grove is the illustrious and industrious California Ground Squirrel known for digging elaborate burrows. Safety from predators, great insulation from the weather in the world above - hot or cold! Their tunnels are planned for the potential of rainy winter days, nestling the cozy nest cavity of the winding network of tunnels above a long-running tunnel to allow proper drainage. However, some of our more intense atmospheric river-type storm systems might still have to break for higher ground when the soil is truly saturated.

Winter is a genuinely uncomfortable time for these squirrels; not only are they thrust out sopping wet into the elements, but I have often noticed elevated red-tailed hawk activity just after these big storms pass through, as the newly homeless squirrels have limited hiding places. Bearing the cold more effectively than others can be advantageous and a great excuse to stay active all winter. 

Many other types of animals will take refuge inside the winding labyrinths dug out by the ground squirrels—western toads, burrowing owls, and even gopher snakes and rattlesnakes muster up some respect for their nemesis's architectural brilliance, striking a short-lived winter truce. The depths of the Earth often provide a cold but at least consistent temperature for many species over winter, but what about the ones stuck outside and exposed to the weather? 

Warmth as a State of Mind 

Many of our species of birds simply bail south for the winter, choosing the exhaustive and dangerous route of migration to find food and shelter, but several birds choose to tough it out for winter. Some even migrate here on purpose! I have often wondered—how on Earth do tiny Annas Hummingbirds keep their blood flowing and not just turn into cute little icicles?

Hummingbirds and many other species of birds, insects, and reptiles are able to enter into a special state called 'torpor.' On cold nights - any time of year not just winter: these birds are able to reduce their metabolic rate up to 95% by allowing their body temperature to drop from their daytime average of 104 degrees down to around 50 degrees, just shy of a fatal temperature. After a night hovering upon the brink of death, they can slowly bring themselves back to life over the course of 20 minutes or so the next morning.

As I scurry from my toasty bed to crank up the furnace in the morning, I try to channel the strength of the tiny hummingbird as I shake off my make-believe torpor. Their winter 'shelter' is more of a state of mind than any physical abode. An immense level of mental fortitude that I wish I possessed! 

Diapause or Die! 

Some insects have found the ultimate way to survive the winter: just skip it all together! Now we are talking! However, this strategy uses the term 'survive' very loosely. Adult Praying mantises are highly effective hunters during the warmer seasons, but in fall, they will lay their eggs somewhere safe and succumb to the onslaught of winter. If the biting cold doesn't do them in, surely the lack of other bugs to hunt and eat will.

Those 'other' insects may be hidden away, relying on a hyped-up version of torpor, called diapause, which is controlled by hormones rather than temperature to stop the temptation to rejoin the waking world on the odd 70-degree winter day as we often are so lucky to get.

Some insects have an extended larval or pupil stage that lasts all winter long, burrowed underground, embedded into a rotting log, or encased in a gall. Some of these organisms even come complete with a sort of organic 'antifreeze' that allows them to partially freeze over without losing vital function. The mantis, however, simply looks deep into the eyes of winter, says, "No thanks," dies, and is survived by the next generation.  

True Grit 

Some of our wildlife opt to grin and bear the weather. One of my two cats at home spends the cold months bouncing between a chance ray of sunshine in the morning, to a heated-blanket nap in the afternoon, to our warm bed at night. Sometimes, I catch her dozing off with her face inches from the scalding hot grate of the furnace. Rest assured that she will let everyone know if she feels the slightest chill. Yes, she is a spoiled cat.

Our local wild Bobcats, coyotes, and other larger mammals do not have such a pampered life. They use a combination of strategies to persevere through the chilly winter months. As the weather starts to shift from hot and dry to cold and damp, these animals will accelerate their consumption of calories to try to build up and sustain larger deposits of fat on their bodies, holding their body heat more effectively.

Their fur coats will also change in response to the seasonal change, giving them a significantly bulkier appearance in the winter. These two methods will help them be more well-insulated to keep their heat, but they will also burn more calories daily to generate more body heat to combat the colder temperatures. Burning more calories means they must continue hunting and foraging to keep up - some of these animals will alter their diet in the winter to cope, sometimes resorting to eating more carrion than they might like. It's hard to be a picky eater when it's life or death! Can someone please explain this to my cat? 

Persevere and overcome 

I am writing this article in my full winter coat: wearing long johns under my pants, fingerless wool gloves (only because it is hard to type with full mittens), a big puffy down jacket, and sipping warm oolong tea. I sometimes think about that squirrel proudly running back to its den with another mouth full of portable warmth. Just like that squirrel, I refuse to let the cold win!

Meanwhile, Ranger Jay just walked into the Ranger Station in a t-shirt - he says our Californian winters are nothing compared to the near arctic conditions of New England, where he grew up. We all find ways to survive the winter. Some of us adapt better to the cold! Now, where did I put that space heater...