The other day I watched two squirrels chasing each other around a tree. I knew why they were doing this but could overhear the people next to me asking each other the question.
If a squirrel is chasing another squirrel, it is usually a male showing dominance to another male. Once they have chased them out of the area, they will pursue a female in estrus. Young squirrels may be seen chasing each other as a form of play and practice for escaping predators.
It is easy to assume that squirrels are just playful. However, there are several other reasons squirrels are often seen chasing each other.
Chasing When Mating
A male squirrel may chase another to exert dominance before the male chases the female. The mating chase has a different pattern and occurs either in late winter or early spring. At this time, adult squirrels are looking for a potential mate. Most squirrels reach sexual maturity at the age of 10 to 12 months.
There are two types of mating chases. The first involves competition between males who want to assert their dominance. Competing males chase until they catch the other. This is often followed by violent fighting among males. In these cases, maturity, size, and strength come into play, and the older squirrel usually wins over younger squirrels.
After a male has emerged victorious, they earn the female’s attention. The females become aware of males who make the most worthy bachelors. Several males stay close to her territory when the female squirrel approaches estrus. Females emit unique scents and vocalizations that attract males from various neighboring areas.
Males wait until the female is ready for mating and becomes receptive. Male-to-male competition occurs, with one establishing dominance when the female begins her mating chase.
Female squirrels sometimes give chase while their suitors are battling it out. Typically, it is the dominant male who will find her first. However, this is not always the case.
The female runs off and entices the males to run after her. Males that can keep up prove how sustainable they are as partners. As the pursuit continues, the male checks the scent released by the female to ensure she is in estrus. This is a crucial activity because female squirrels are in heat for only a few hours.
The chase continues with the two chasing each other around tree trunks and fields before the male finally manages to catch his partner. Once the pursuit is over, the squirrel’s mate. If you see squirrels chasing, you are probably just witnessing a normal part of the mating process of squirrels.
There are exceptions to the rule, and some squirrels may avoid this altogether. In some instances, younger males may wait within a female’s territory. By doing this, they avoid the chase and wait for the female to stop the pursuit. The male attacks the dominant squirrel and tries to chase him away. On a few occasions, the female gets injured in these vicious attacks.
Protecting Their Territories
Some species of squirrels are very territorial, while others may not be territorial but exhibit this behavior if there are too many in one location. Protection of a territory is attributed to a lack of nesting places or limited food within the area.
American red squirrels and California ground squirrels are the most territorial of all North American species, while gray squirrels are the least territorial. Squirrels protect their territories by chasing away other squirrels or intruders. They continuously pursue and nip at the intruders until the danger has passed. These disputes are quite easy to spot and differ from the mating chase.
Baby squirrels usually move away or are chased away by their mothers to establish their territories once they are mature enough. This can be up to 80 meters from the mother’s territory. The mother may share part of her territory with the offspring rather than chasing them away. Some females may give up their already established territories to increase their offspring’s survival odds.
Northern flying squirrels have a different pattern regarding territorial behavior, as males are not territorial, but females can be. Females will become territorial when there are fewer potential nesting sites to raise their young.
Another species of squirrel that is territorial is the male California ground squirrel. Their home range does not include other males, and they will aggressively chase away intruders. Ground squirrels live in burrows and have a territorial range of approximately 75 yards.
The burrows are very important to squirrels, as it takes a lot of effort to build one. Their shelters are their primary means of surviving in the wild, where they hide from predators. For this reason, California ground squirrels will chase away intruding squirrels who try to encroach on their territory.
Chasing For Play
Young squirrels engage in playful chasing and a form of play fighting. They run after each other happily as kittens and puppies would, and you can often see young squirrels playing high in trees.
This type of play is beneficial to juvenile squirrels. They chase for much more playful reasons, which helps them develop coordination and strength skills. This type of play does not usually result in aggressive behaviors, with only playful nips occurring.
Protecting Food Supplies
Some species, such as gray squirrels, are not territorial, and many can live together in one location. Females are more protective of their nests, but males do not seem to mind who else is in the territory.
As winter arrives, food is scarce for gray squirrels, and with many squirrels living in the same area, this can bring about high competition for limited food supplies.
American red squirrels tend to be a solitary species. They are territorial, which is critical for their survival. The American red squirrel diet consists of seeds from conifer trees. Squirrels are pretty industrious and collect as many cones as they can find.
The cones are heaped into a giant pile referred to as a midden. If you see red squirrels fiercely defending their territory, this is usually to protect their valuable food reserves. The aggression and chasing to defend a midden can be fierce.
Squirrels often have to chase others away to protect their food. To survive, these animals know they must protect their food sources. This is one reason why it may be difficult for them to live in areas with little food. There may eventually be a time when disputes emerge, causing them to chase others away from the site.
References and Further Reading
“Squirrels: The Animal Answer Guide” by Richard W. Thorington Jr. and Katie Ferrell
“Squirrels: A Wildlife Handbook” by Kim Long
“The Squirrels of North America” by Richard Thorington and John Koprowski
“Squirrels: A Natural History” by Richard Thomas
“Squirrels in the City: Life among the Urban Wildlife” by Michael Mesure
Thorington, R.W. and Hoffmann, R.S. (2005): “Family Sciuridae.” In: Mammal Species of the World: A Taxonomic and Geographic Reference: 754–818. Johns Hopkins University Press, Baltimore.