Ground squirrels are burrowers and sleep in underground dens. Tree squirrels and flying squirrels prefer to transform cavities in trees or other structures into snug squirrel nests or dens. If they cannot find a suitable cavity to convert into a den, they will construct a woven dray high up in a tree fork or a clump of branches, where they can sleep safely.
Tree squirrels, flying squirrels, and ground squirrels are different types of squirrels that nest differently. Tree squirrels and flying squirrels live in trees or tall structures, while ground squirrels live mostly underground. Squirrel dwellings can vary depending on the type of squirrel, their geographic location, and the season.
The average squirrel can almost be classified as a real estate magnate since they rarely own just one shelter. They build intricate underground dwellings or, in the case of tree squirrels, they build second and even third nests. Are you a little jealous? Read on for some squirrelly real estate facts!
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Where Do Squirrels Sleep?
Almost all squirrels are both diurnal and crepuscular (not as bad as it sounds!). Diurnal means that they forage for food during the day, and sleep at night.
Squirrels are also crepuscular. That means that they are generally not extreme sun-lovers, but prefer to wake up at dawn to dash around energetically during the early morning. They return to their nest to sleep, eat, and rest during the hotter hours of the day, and only resume their boisterous activities again near dusk.
They need snug, enclosed dens where they can curl up and sleep for around 15 hours every day. This is a normal, daily sleep pattern, and should not be confused with hibernation (during winter months) or estivation (during hot summer months). Baby squirrels sleep for 18 hours a day and depend on the female adult for food, drink, and cleaning during their first 8 weeks of life.
Squirrels Hibernate and Estivate
Tree squirrels and flying squirrels have developed different ways to escape extreme temperatures and lean periods. They’ve learned to add to the thickness and density of the walls of their drays by adding more layers just before the winter, but they also actively remove the material as needed to provide ventilation in summer. They are seldom exposed to extreme direct sun or snow.
Ground squirrels are more exposed to extreme cold and heat and have adopted additional defenses to cope with these seasonal conditions, namely hibernation, and estivation.
The Metabolism of a Hibernating Animal Slows Down to Preserve Energy. Their core temperature drops, and their heartbeat, breathing, and all bodily functions slow down to preserve bodyweight and health when it is too cold and dangerous to venture out to forage.
Ground squirrels hibernate for up to five months every year. They prepare for winter with a frenzy of activity to fortify their burrows and collect food to last through the winter when there is no food outside. They do, however, wake up to eat and urinate outside, spending around 20 hours a week awake.
Tree squirrels and flying squirrels do not hibernate. They stick to their routine during winter – albeit a little later in the morning, and return to their well-insulated nests well before dusk. They, too, have a period of high activity just before winter when they store food for the lean months and fortify the insulation of their dens or drays.
The body temperature of an estivating animal remains as low as possible. During the warmest summer months or very dry spells an estivating animal will keep as still and inactive as possible during periods of severe conditions.
Adult ground squirrels may estivate during the two to three hottest months every year. During this time they move and eat very little, and spend their time in deeper, cooler underground sections behind entrances blocked with dirt.
Three Types of Squirrel Homes For Sleeping
Squirrels are house-proud and home-loving but they almost always have multiple nests or shelters to provide them with a quick retreat in times of danger. These additional shelters can be abandoned birds nests or purpose-built shelters that are seldom as well-crafted as the primary base, or may even be a bare woven twig platform with loosely piled leaves and moss.
Ground squirrels are energetic diggers who construct and maintain quite sophisticated tunnel systems, often with halls or spaces that serve a particular function like sleeping or food storage. Like their more agile tree-living cousins, ground squirrels line their underground dens with leaves, grass, and anything else that might provide insulation against winter cold and summer heat.
Like tree squirrels, ground squirrels can climb well and aren’t afraid of trees, barns, or fences, but they prefer open spaces like well-irrigated grassy fields or pastures. They instinctively avoid flood-prone areas by digging their tunnels on sloped ground.
Ground squirrels are tidy creatures with clean, rather discreet tunnel entrances of about four inches in diameter. They usually try to hide the tunnel entrances under logs or near rocks that will deter other animals or predators from digging in the area.
They are energetic burrowers, and will eventually create and actively maintain an intricate system of underground tunnels with many different escape routes and entrance holes.
A well-settled group of squirrels requires space to sleep, store food, raise their young, and hibernate or estivate. They can burrow tunnels of up to 25 feet long, complete with wider halls or roomier sections where they can curl up, turn around, or stock their food stores for winter.
Tree squirrels will readily venture to ground level, but they prefer heights for safe nesting. Their dens can be found from around 20 feet or as high as 45 feet up from the ground.
A den is a squirrel nest that has been built into an existing natural cavity in a tree trunk, hollow tree center, or even an abandoned woodpecker nest on the side of a tree trunk. Tree squirrels prefer to start with that firm base to which they can just add a woven vertical ‘wall’ around the natural opening, and then increase protection from the weather by weaving twigs, leaves, grass, and fur into the extension.
If there is a shortage of natural cavities for dens in the area, tree squirrels will settle for constructing large, individual leaf-and-twig nests, otherwise known as drays. A dray is a round shell with a woven foundation of sticks and moss which has been secured to a tree. The squirrels then weave an additional wall-like shell of twigs similar to the foundation, building upwards from the base to form protective sides.
The dray is then further lined with leaves, twigs, moss, grass, and fur to provide comfort for delicate baby squirrels, and of course warmth for all during the winter. The finished dray is about two feet wide and one foot high, is usually well-hidden in dense vegetation and is secured in a sturdy tree fork or nested at the base of a spot where a few branches fork. An adult squirrel can construct a dray within about six hours.
Tree squirrels will occasionally move into abandoned drays built by other squirrels, or will at least use abandoned drays as temporary shelters. Female tree squirrels usually raise their families alone or may share their nest with another female during winter. Males and females rarely share winter homes.
Flying squirrels sometimes visit the ground, but they much prefer higher ground and will always try to occupy a high position in a tree cavity or even the rafters of human structures to take full advantage of their unbelievable agility.
Flying squirrels are much more social than either tree- or ground squirrels, and they often form bands or groups of around ten adults to build a collaborative nest. They enjoy the body heat of their nestmates and the safety of numbers, but their collective effort also helps them to build sturdy, well-insulated communal nests for protection against extreme winter temperatures.
Squirrels are primarily herbivores, but cannot digest cellulose (fiber), hence their diet of nuts and seeds which are rich in protein, fats, and carbohydrates. They collect and store nuts and seeds for winter eating, but by early spring the nuts they buried in the fall have sprouted and become inedible.
It’s a hard time for squirrels. Tree squirrels will at this time rely almost completely on eating the fresh young buds on their host trees, and ground squirrels try to stretch their hibernation period to avoid the very lean period. However, when squirrels get very hungry, almost all types of squirrels will eat some form of meat like insects, bird eggs, or small birds or rodents.
Continue Reading: What Can You Feed Squirrels In Your Backyard?
Squirrels are fascinating and very active animals with large appetites and a great talent for sleeping You can generally assume that, when they are not outside and actively foraging for nuts, seeds, acorns, and other squirrelly delights, they are either caring for their young, maintaining their abodes, or having a good old snooze.