Squirrels, common backyard inhabitants, often spark curiosity about their sleep patterns and whether they hibernate. Their active daylight hours lead many to wonder how these busy creatures rest.
Squirrel Sleep Duration and Habits
Most diurnal squirrels sleep 11 to 15 hours daily. This sleep occurs in multiple short bursts throughout the day, with a longer period of rest at night. After daylight activity, they retreat to their sleeping spots.
Squirrels primarily sleep in dreys, well-constructed nests of twigs, leaves, and moss built in tree branches or cavities. They also use natural tree hollows, which offer shelter from weather and predators. When sleeping, squirrels often curl into a ball, tucking their heads and tails close to their bodies to conserve warmth.
Factors Influencing Squirrel Sleep
Several elements alter a squirrel’s sleep duration and quality. Different squirrel species exhibit varying patterns; ground squirrels, for instance, can spend up to 84% of their day sleeping. In contrast, tree squirrels, like the common gray squirrel, maintain a more active daily schedule.
Seasonal changes also play a role. Colder weather and reduced winter food availability often lead to longer rest periods. Tree squirrels may sleep more in their nests during cold spells, slightly lowering their heart rate and body temperature to conserve energy. Food availability directly impacts activity levels; scarcity can lead to increased sleep to conserve energy. A secure nesting site, protected from predators, also enables deeper, more consistent sleep.
Distinguishing Sleep from Hibernation
A common misconception is that all squirrels hibernate. Hibernation is a distinct physiological state of metabolic depression, characterized by a significant reduction in body temperature, slowed heart rate, and decreased breathing. This adaptation conserves energy during prolonged food scarcity or harsh environmental conditions.
True hibernation is primarily observed in ground squirrels, which enter a deep, prolonged state lasting weeks or even months. During this time, their body metabolism significantly slows, relying on stored fat reserves. Most tree squirrels, including gray, red, and flying squirrels, do not truly hibernate.
Tree squirrels may, however, enter torpor, a temporary and less extreme reduction in metabolic rate and body temperature. Torpor can last a few hours to several days, allowing them to conserve energy during severe cold snaps. It is not the same as true hibernation. Squirrels in torpor can easily wake up to forage for food, unlike true hibernators who remain largely unresponsive.