Squirrels are a common sight in many backyards and parks, often seen darting across lawns or scampering up trees. While active much of the year, their winter activities might seem less apparent. Despite the chill, these adaptable rodents employ various strategies to survive winter.
Tree Squirrel Winter Dwellings
Tree squirrels, such as Eastern Gray Squirrels and Red Squirrels, primarily rely on two types of elevated shelters for winter protection. One common dwelling is a drey, a spherical nest of twigs, leaves, and moss, typically high in deciduous trees. These insulated structures provide shelter from cold winds and precipitation, helping conserve body heat.
Alternatively, tree squirrels frequently utilize natural tree cavities or abandoned woodpecker holes for their winter homes. These hollows offer superior insulation and protection from the elements compared to dreys. A tree cavity creates a stable microclimate, shielding squirrels from harsh winter conditions and predators. Less commonly, in urban settings, tree squirrels may find temporary refuge in human-made structures like attics or sheds, though natural dwellings are preferred.
Ground Squirrel Winter Habits
Ground squirrels, including groundhogs and other ground squirrel types, have distinct winter living arrangements compared to tree-dwelling relatives. These squirrels construct extensive underground burrow systems, which serve as their primary winter residences. A typical burrow features a network of tunnels leading to various chambers, including sleeping areas and food storage spots, often with multiple entrances for escape.
These subterranean dwellings offer significant protection from freezing temperatures and predators throughout the winter. Many ground squirrel species enter a state of true hibernation or deep torpor within these burrows during the coldest months. During hibernation, body temperature drops significantly, heart rate slows dramatically, and metabolism decreases to conserve energy, allowing them to survive long periods without food.
How Squirrels Endure Winter
Beyond their specialized dwellings, squirrels employ several survival strategies to endure the winter season. Food caching involves burying or hiding nuts, seeds, and other edibles during warmer months for later retrieval. Tree squirrels often engage in scatter hoarding, burying individual food items across a wide area, while some ground squirrels practice larder hoarding, accumulating food stores in specific burrow chambers.
Squirrels also exhibit physiological adaptations that aid their winter survival. They grow a thicker winter coat, providing an extra layer of insulation against the cold. Shivering is another adaptation, allowing them to generate internal heat when temperatures drop.
While ground squirrels largely hibernate, tree squirrels remain active throughout winter, relying on cached food supplies and insulated nests to navigate the chilly landscape. Their ability to stay active allows them to forage even in cold conditions.