Squirrels, members of the Sciuridae family, are found across a wide range of environments globally, excluding only Antarctica and Australia. These adaptable rodents inhabit diverse ecosystems, from dense forests to bustling urban landscapes.
Natural Habitats and Home Locations
Squirrels exhibit varied preferences for their living spaces, largely depending on their species. Tree squirrels, such as the eastern gray squirrel, typically inhabit mature forests and woodlands, thriving among deciduous and mixed trees like oaks, hickories, and maples that provide both shelter and food sources. They also frequently adapt to suburban and urban environments where mature trees are present, finding suitable homes in parks, residential areas, and even cemeteries.
Ground squirrels, conversely, make their homes in open areas, including rocky outcrops, fields, grasslands, and sparsely wooded hillsides. These species, like the California ground squirrel, are adept at constructing intricate burrow systems underground. Beyond natural settings, squirrels often utilize human-made structures for shelter, such as attics, sheds, wall voids, or chimneys. These locations offer warmth, safety, and protection from predators, prioritizing security, food access, and refuge from environmental conditions.
Constructing a Squirrel’s Dwelling
Squirrels construct two primary types of dwellings: dreys and dens, each serving distinct purposes. A drey is a spherical nest typically found high in tree branches, often at least six meters above the ground. These structures are woven from twigs, leaves, and bark, with an insulated inner lining of softer materials like moss, feathers, grass, and shredded bark. Dreys function as nurseries for young and as shelter during inclement weather.
A den refers to a home established within a natural cavity, such as a hollow tree trunk or a deserted underground burrow. Squirrels may also adapt human-made spaces like attics or wall voids into dens. Dens are often lined with soft materials, providing warmth and protection. While dreys are often summer homes, dens are preferred for winter due to their superior insulation. Squirrels may maintain multiple dreys or dens as backup shelters or to evade parasites.
Squirrel Sleep Patterns and Winter Readiness
Most squirrel species are diurnal, meaning they are active during daylight hours and sleep at night. Their activity peaks occur in the early morning and late afternoon, aligning with optimal foraging conditions. During the night, squirrels retreat to their dreys or dens for rest.
Unlike some other mammals, squirrels do not enter a prolonged state of hibernation. Instead, they employ torpor during severe cold spells, a state of reduced metabolic activity that allows them to conserve energy. They frequently rouse from torpor to forage for cached food.
To prepare for winter, squirrels accumulate fat reserves through increased eating in autumn, which provides energy and insulation. They also engage in extensive food caching, burying nuts and seeds in various locations (scatter hoarding) or in communal stashes (larder hoarding) for retrieval during periods of scarcity. Their thick fur coats aid in insulation, and huddling together in their nests provides additional warmth.