The grey squirrel, Sciurus carolinensis

Much has been said and written about the conservation issues concerning the conservation impact that the grey squirrel has had on our native red squirrel, indeed it has been reviewed in great detail on this site. {click on banner RED,GREY SQUIRRELS--} in the content banners above.

However, on this page I review the grey squirrel, one of our most familiar mammals as a part of the British fauna in its own right. It was introduced into Britain during the 1800s, but, it was not until the 1900s that they became well established in the wild.

Squirrels {and sometimes rabbits} are active by day and so they are familiar to most people. This activity make the mammal one of the easiest to study and this little woodland mammal engages in all kinds of interesting behaviour. They are agile, adaptable and intelligent, which has been proved time and time again, as bird lovers construct complex obstacles to stop the squirrels from taking the food meant for the birds. Most of them, are thwarted by the squirrels, who seem to find away of procuring the food come what may.

Grey squirrel a robust squirrel species

Courtesy of grendeljkhan {Flickr}.  CC BY-SA 3.0 License

Description of the grey squirrel

The body length of the grey squirrel is between 204-285 mm with a tail length of 195-240 mm.

They weigh between 400-600 g a pregnant female may be heavier.

In winter the fur is of a silvery grey colour with a brownish tail fringed by silvery white hairs. the greys tail is of a grizzled texture and does not change colour at any time of the year. The tail is used for balance and for signalling , especially aggression. During the summer the fur is often tinged with a reddish brown colour , which often leads to them being mistaken for the native red  which are much smaller.

The ears are prominent and rounded and unlike the native red never have ear tufts even during the winter. The hind legs are surprisingly long and very powerful enabling the squirrel to leap great distances in its woodland home. They are capable of hanging onto the flimsiest of branches even in high winds. They are capable of scampering up and down tree trunks, even defying gravity by scampering down the trunk head first. The mammal has double jointed ankles enabling its feet to turn backwards. They are capable of hanging upside down, by its toes, Its sharp claws even allow the squirrel to climb up brick walls with ease.

The grey squirrel is well adapted for life in the tree tops. Drey clearly seen

Courtesy of Palmiped CC BY-SA 3.0 License.

Black and white variations

There are areas where the colouring of this mammal varies, such as an area around Bedfordshire in the south of England, where silky black specimens are often observed. True Albinos have also been recorded, being pure white with pink eyes, again these seem to be confined to south east England.

Life style of the grey squirrel.

This mammal is truly adapted for its woodland home. However, it is not confined to woodland they are very common in parks and gardens so long as there are trees available nearby. In parks and gardens where people are regular visitors the animals can become very tame. 

Squirrels are active during the day and will often be seen sat upright at a vantage point as they survey their surroundings, relying as much on eyesight and smell for information, as they do on their hearing. 

Squirrels often sit up to survey their surroundings

Courtesy of Krinx  CC BY-SA 2.5 License.


The grey squirrel is well adapted for its arboreal life style yet they often feed on the ground, especially so during the autumn. In very hot weather in summer time I have observed the squirrel down by the edge of the lake taking a drink. This is very unusual fro squirrels are very wary of water, for they are poor swimmers. The tail which is thick and heavy when wet soon gets water logged which may contribute to the squirrel drowning.

The squirrels diet is varied as this adaptable mammal takes many kinds of food. During the spring they will eat the buds of trees. Later they will eat caterpillars that are abundant among the trees foliage. They will take the eggs of birds should they encounter them in their quest for food.

During the autumn the countryside is awash with food for these creatures, acorns, hazel nuts, beech mast, "conkers" sweet chest nut, and all manner of fruits and seeds are available to them.

They take hazel nuts while they are still green, leaving the forager with little chance of finding the ripe hazel nut in the north of England. 

Grey squirrels take hazel nuts while they are still green



Hidden bounty

During the autumn the squirrels spend much of their time gathering food and concealing it much of it will be buried. the feet of the squirrel is also adapted for digging which makes this task much easier to accomplish. This hidden bounty will be of the utmost importance during the winter months and for the following seasons breeding success. The heavier the females are at the beginning of the breeding season the better the chance of the young survival rate . It will also help the mother to have plenty of available milk to feed her offspring.

Grey squirrel breeding.

Squirrels do not hibernate and their breeding season starts as early as January when courtship chases may be observed as the squirrels chase each other around tree trunks, among the boughs and across lawns.

The young are born from February onwards. Up to 7 babies may be produced in a single family but three or four is the more the norm. The babies are born blind and helpless at birth weighing around 15g. If the mother is disturbed or feels insecure she may well move the young to another place of safety. The male plays no part in the rearing of his off spring.

They take about three weeks to grow fur and up to a month to open their eyes.They get a full set of teeth at around five weeks but do not leave the dray or eat solid food until about  seven weeks of age. They finally leave their mother and become independent at two to two and a half months old. The mother may then have another litter during July. The juveniles leave their families and disperse, some times some distance away from where they were born.

Young inexperienced squirrels often fall victim to predators or killed by fast moving traffic. More than half will perish in the first year of their lives. Those that do survive may live for several years . The maximum life span in the wild is believed to be between 8-10 years.

They start to breed in the following season of their birth, thus the cycle of life{and death} starts a new. 

Grey in Conifer branches

Courtesy of Natalie-S  CC BY-SA 4.0 License.

Reuse of images.

The images on this page may be reused. However, the name of the relevant author must be attributed along with any accompanying license.