Squirrels Survive in Winter
Ethan Sullivan
| 15-04-2024
· Animal Team
Squirrels go into overdrive as the bright summer days fade into the brisk autumn air. These hardworking tiny animals work tirelessly during the fall months to acquire, store, and conceal enough food to last them through the hard winter.
Gathering as much acorns, nuts, seeds, fungus, berries, and flora as they can before the winter sets in is a race against the clock and the weather.
The process starts in late summer as squirrels begin cutting green cones and burying them in shallow holes.
As fall arrives, the real stockpiling begins in earnest. Squirrels gather as much food as they can, burying it in thousands of scattered caches across their territory. Each cache is just a few nuts or other food items, carefully tucked away in small holes dug in the ground and recovered with soil and debris to hide the scent from animals that may want to raid the store.
How do they remember where they buried all those caches? Squirrels have an incredibly keen spatial memory that allows them to recall locations relative to landmarks and geometric patterns in their environment. Their densely folded brains are specially evolved for this complex task. Studies have shown squirrels can remember burying up to tens of thousands of caches each season and are able to retrieve most of them over the course of the winter. It's an astonishing feat of memory.
Not only do they squirrel away food in the ground, but they also stash provisions in tree cavities, underground chambers, logs, and any other nooks and crannies they can find for extra storage space. When times get really tough in the dead of winter, squirrels will even strip away tree bark and dine on the sap, buds, and inner bark as a high-calorie food source to stay alive. They are the ultimate survivalists.
As winter sets in, squirrels spend more and more time in their dens, which can be hollow trees, underground chambers with brushy nests, or even squirrel-made leaf nests in the forks of trees. Tree squirrels tend to make their dens in trees, while ground squirrels dig burrow systems underground. Squirrels group up in their winter dens, often combining forces by sharing a den with their offspring and other related squirrels to pool body warmth on the coldest nights.
On mild winter days, squirrels will venture out of the warmth of their dens to search for and retrieve their buried food caches, using their superior sense of smell and memory to locate the underground stashes. They'll gather up as much as they can carry in their cheek pouches and return to the den to eat. They'll also take the opportunity to scout for any newly available food sources exposed by fallen trees and branches.
If heavy snow blankets the ground, squirrels may choose to stay put for days or weeks, subsisting only on the cache of nuts and vegetation stored right in their den. This hoarding behavior allows them to stay nice and cozy while riding out the worst winter storms. They'll work on excavating tunnels through the snow when they need to head out for food and scouting. Some squirrels will lose upwards of 25% of their body weight over the winter as their food stores run low, but their furry tails can be a crucial source of insulation on the coldest nights.
Overall, squirrels have adapted some incredible physical and behavioral traits to survive the cruel winter conditions. Their prolific hoarding and burying behavior, coupled with their amazing memories and insulation capabilities, allow them to tough it out until spring returns once again. Next time you see a squirrel madly stockpiling for winter, you know you are witnessing an amazing feat of preparation and survival.