Squirrels, known for their energetic pursuits during daylight hours, also require significant periods of inactivity. Understanding their sleep habits offers insight into their daily lives.
Typical Sleep Duration
An average squirrel typically sleeps for about 14 to 15 hours each day. This considerable amount of rest accounts for approximately 60% of their 24-hour cycle. Their sleep is not continuous; instead, they often take multiple shorter naps throughout the day. For instance, certain crepuscular species, like the gray squirrel, may sleep around 13 hours daily, often in intervals of two to three hours. Ground squirrels, in particular, can spend up to 84% of their day sleeping. This extensive sleep duration is important for maintaining their high-energy activities.
What Influences Squirrel Sleep
Several factors can affect a squirrel’s sleep patterns and duration. Different squirrel species exhibit varied sleep behaviors; for example, ground squirrels tend to sleep more than their tree-dwelling relatives. Seasonal changes also play a role, with temperature, food availability, and predator presence influencing how much a squirrel rests. Conversely, in very hot summer weather, they might choose to nap during the warmest parts of the day.
Age and daily activity levels can also impact a squirrel’s need for rest. Younger squirrels, or those engaged in more strenuous daily routines, generally require more sleep. Their diet and energy needs also influence rest requirements, as ample sleep is necessary for energy replenishment.
Sleep Versus Other Rest States
It is important to distinguish a squirrel’s true sleep from other states of inactivity, such as torpor and hibernation. Torpor is a state of decreased physiological activity where a squirrel’s metabolic rate significantly slows, sometimes reducing by 50-70%. During torpor, their heart rate can drop from 100-200 beats per minute to as low as 4-10 beats per minute. This state is a lighter form of inactivity compared to true hibernation, allowing the squirrel to be awakened more easily. Torpor helps squirrels conserve energy when temperatures are low or food is scarce.
Hibernation, a more prolonged and deeper state, is primarily observed in ground squirrels, lasting anywhere from four to eight months. During hibernation, their body temperature, heart rate, and energy needs are significantly reduced. Most tree squirrels, including gray, fox, red, and flying squirrels, do not truly hibernate. Instead, they might enter periods of torpor or simply spend more time resting in their dens during harsh winter conditions. They prepare for winter by storing food, building fat reserves, and insulating their nests.
How Squirrels Find Rest
Squirrels choose specific locations for rest that provide safety and comfort. Tree squirrels, for instance, often sleep in structures called dreys, which are nests made from twigs, leaves, grass, and moss. These dreys are typically built in the forks of tall trees or within natural tree cavities, offering insulation and protection from weather and predators.
Ground squirrels, in contrast, create intricate tunnel systems underground, known as burrows, for their sleeping quarters. In urban environments, squirrels may adapt by finding shelter in human-made structures like attics, chimneys, or wall cavities. When sleeping, squirrels frequently curl their bodies into a tight ball, tucking their heads and tails close to conserve body heat.