Scientific name: Sciurus carolinensis
Size: Body approximately 25cm. The tail is around 20cm
Distribution: Found throughout most of southern England (except the Isle of Wight), Wales, some parts of Scotland and Northern Ireland.
Months seen: All year round
Life span: Up to 6 years
Habitat: Woodland, parks and gardens
Food: Eats mostly nuts and seeds. The front teeth of the grey squirrel are continually growing, and to prevent them getting too long, they need to constantly nibble on something to grind them down
Special features: The grey squirrel frequently has patches of reddish-brown coloured fur, and we often get asked if this is the product of cross breeding with red squirrels. It isn't. In fact grey squirrels are more often half grey and half brown.
To add further confusion there are also some colonies of white Grey Squirrels in Kent, Sussex and Surrey.
There is also a number of black Grey Squirrels which are mainly concentrated around Bedfordshire and Cambridgeshire.
The grey squirrel is a native of north-east America. Its range there stretches from Quebec down through New Jersey and Pennsylvania. It was first recorded in the UK in the 1820s, but was not released into the wild until 1876 when allegedly a chap named T. V. Brocklehurst liberated a pair in Cheshire.
Why they were released is still a bit of a mystery. The most likely reason is that it fitted in with the Victorians' ideal of reshaping all aspects of the world, and it became the fashionable thing to do. At that time very few people were aware of the damage that this might cause to native wildlife.
More introductions followed, like the pair which were released at Loch Long in 1892. As a result of this, grey squirrels spread to the eastern side of Loch Lomond and into Stirlingshire - an area of 300 square miles in less than 25 years.
During the autumn months you might see squirrels burying acorns and nuts. They do this to provide for the winter months when food is scarce. They can usually find the buried food again by using their strong sense of smell. If you find pine cones nibbled to the core its a sure sign that squirrels are about.
One of the more destructive habits of the grey squirrel is to chew the bark off trees to get to the fleshy green wood underneath. This can sometimes kill the tree, and makes grey squirrels unpopular with foresters.
Grey squirrels can also carry the squirrel parapox virus which is fatal to our native red squirrels. Grey squirrels rarely die from the disease because they've developed antibodies.
The droppings of Grey Squirrels look similar in shape and size to those of rabbits, but they are more shiny and densely packed because of the different diet.
The Grey Squirrel breeding season starts in January and finishes around June. This is when they are at their most obvious. If you walk through a wood at this time of year you can often see the males chasing the females in the tree tops, and hear their screeching calls.
Hear a Grey Squirrel Call
Female Grey squirrels can have one or two litters a year, each producing between one and seven young. The young Grey Squirrels look like slightly smaller and thinner versions of the adults.
The squirrels home, known as a drey, is built in a tree from twigs and dry leaves. In the summer months the drey looks like a leafy platform, while in the winter months it is deeper, about the size of a football, and acts as a nursery for the young.