If you’ve ever seen an adorable family of squirrels scurrying around your backyard, you may have wondered exactly how many of the bushy-tailed critters live together. Squirrels are highly social creatures that often nest in groups, but the number can vary based on species, habitat, and time of year.
If you’re short on time, here’s a quick answer to your question: squirrel nests or dreys typically house 2-10 squirrels on average, but may temporarily have more during breeding season or in colder climates where they huddle for warmth.
Squirrel Nesting Habits
Tree Dreys
Squirrels are remarkable creatures when it comes to building nests called “dreys” in the branches and forks of trees. They construct these dreys both for breeding purposes and to have a cozy place to sleep during cold weather (squirrels don’t actually hibernate in the winter despite popular belief!).
Tree squirrels like eastern gray squirrels and fox squirrels build a drey made of interwoven twigs construction and lined on the inside with moss, thistledown, dried grass, and feathers. The result is a dense, water-resistant structure that provides insulation and protects the squirrels from wind and rain.
Amazingly, squirrels build these intricate tree nests in the crook of a branch, wedged up against the tree trunk. This helps anchor the nest in place and keep it balanced. Squirrels are evidently skilled engineers!
Some key facts about tree dreys:
- They are usually built 20-60 feet off the ground near the trunk of a tree.
- Dreys can measure up to 2 feet in diameter.
- Squirrels may have multiple tree nests they rotate between.
Mother squirrels will give birth and raise babies in these leafy orb nests. Data suggests an average of 3 baby squirrels (called kittens) are born in each litter. The mama squirrel then feeds and cares for them in the tree drey until they mature enough to be independent.
Ground Nests
While tree squirrels prefer to build dreys up above the forest floor, certain species like prairie dogs actually burrow and construct underground nest chambers. These intricate tunnel systems with rooms provide protected sanctuaries safe from predators and extreme weather fluctuations on the harsh prairie.
A few key facts about prairie dog ground nesting habits:
- Prairie dog coteries build vast underground “towns” spanning hundreds of acres sometimes.
- Each prairie dog family of 4-6 members sleeps in one grass-lined bedroom chamber in the burrows.
- Upwards of 10-20 prairie dogs from an extended colony may live communally across interconnected nest tunnels. Talk about close quarters!
Average prairie dog litter size | 4-5 pups |
Time baby prairie dogs emerge aboveground | About 6 weeks old |
Depth of prairie dog nest tunnels | Up to 16 feet underground |
Mother prairie dogs give birth and raise young pups in in these intricate burrow systems dug deep down beneath the prairie soil. Parents and offspring snuggle together resting and playing safely from predators within the chambers and tunnels. Now that’s what I call a perfect prairie crib!
Number of Squirrels per Nest
Breeding Season
During the breeding season in late winter and early spring, there may be up to 10 squirrels living in a single nest (Purdue University). Female squirrels all give birth around the same time, and the babies remain in the nest together for safety and warmth.
So a nest may contain a mother squirrel, her recent litter of 3-6 babies, and sometimes a couple of juvenile squirrels from her previous litter. The most squirrels likely to occupy a single nest is when new babies are born.
Winter Months
In the winter months when it’s cold, squirrels may share nests for warmth and comfort. Researchers have observed winter nests containing 6-12 squirrels (PAWS). They crow d together in cavities of tree trunks, abandoned birds’ nests, and leaf nests.
Squirrels also huddle together in winter nests to conserve energy and body heat when food is scarce.
Average Range
Season | |
Breeding season | 3-10 |
Non-breeding season | 1-5 |
Winter months | 6-12 |
Factors That Influence Group Size
Species
The species of squirrel plays a major role in determining average group size (Sciurus). For example, Eastern gray squirrels tend to be more solitary with smaller group sizes of around 2-3 individuals. In contrast, fox squirrels and pine squirrels often form larger colonies with over 10 members.
The differences likely relate to variations in social structure between species as well as geographic range.
Climate and Geography
Climate conditions and geographic location impact resource availability, which in turn influences squirrel group sizes. Colder climates with harsh winters mean fewer nuts and seeds, supporting smaller groups. For instance, squirrel nests in northern boreal forests average just 1-5 members.
Meanwhile, warmer climates allow year-round breeding and bigger litter sizes, enabling larger colonies exceeding 30 squirrels in tropical regions.
Predation Risk
Areas with more predators like hawks, snakes, bobcats, and coyotes force squirrels to form tighter-knit groups for better protection. Interestingly, research shows that increased vigilance in larger squirrel groups lowers mortality rates.
Additionally, squirrels emit alarm calls when spotting predators, quickly alerting others to take cover.
Availability of Resources
High Resource Availability | Allows for larger group sizes as there is enough food to sustain more squirrels in an area. |
Low Resource Availability | Limits group size growth since fewer resources can only support small numbers of squirrels. |
The availability of key resources namely food (nuts, seeds, fungi, crops) and nesting sites correlates strongly with squirrel colony size. Places overflowing with acorns, hickory nuts, aromatic truffles (high resource availability) permit groups up to 30+ squirrels.
Conversely, areas with sparse oaks or pines producing limited seeds (low resource availability) restrict groups to less than 5 members.
Social Behavior and Interactions
Cooperative Rearing
Squirrels live together cooperatively to raise their young, with related females sharing a nest and assisting with nursing and protecting the litter. According to research, cooperative rearing improves the survival odds for pups, as the sharing of duties enables the mothers more time to focus on their own sustenance and fitness.
Females within one nest will even synchronize their reproductive cycles to facilitate group rearing of young.
Dominance Hierarchies
There are dominance hierarchies within squirrel nests and communities, as some squirrels become more dominant and have priority access to the best food sources and nesting areas. According to a study on fox squirrels, rankings in the hierarchy were found to be relatively stable over time.
The dominant squirrels tend to be larger and more aggressive in competing for resources.
Territoriality
Squirrels are highly territorial animals. They have specific home ranges where they construct their leaf nests and forage for food. According to experts, the size of a squirrel’s territory can vary greatly depending on the environment, the availability of resources, and even the species of squirrel.
For example, red squirrels may claim a territory of .5-10 acres, while the larger fox squirrel claims about 20-100 acres on average.
Squirrels use complex communication methods, involving both vocalizations and tail signals, to mark the bounds of territories and warn intruding squirrels. Direct chasing and fighting between squirrels over territorial disputes is also commonly observed in parks and backyards.
Maintaining an exclusive territory ensures the resident squirrels have sufficient access to nesting sites and sustenance within an area.
Conclusion
In summary, while the number of squirrels sharing a drey may fluctuate based on various environmental conditions, most nests support small groups of 2-10 individuals on average. However, during breeding season or in harsh winters, substantially larger aggregations can form.
The complex social structure and communal habits of these agile rodents allow them to thrive across diverse habitats.