Grey Squirrel

Field guide to the most commonly encountered mammals and birds

Here, we provide some basic information regarding commonly observed species (plus some others about which we have had queries).

Feel free to contact us by email if you have any questions regarding species you have encountered on the site.

For more information about mammals, we recommend the Mammal Society's species hub, here, and MammalNet here. For birds, excellent resources are available from the RSPB (here) and the BTO (here).

Scientific Name: Sciurus carolinensis

Family: Sciuridae

Appearance: Larger than the red squirrel, greys are coloured as their name suggests. White individuals are occasionally reported.

Body length: 42-55 cm Tail length: 19-25 cm

Weight: 400-600 g

Natural history: Grey squirrels are invasive in the UK, having been introduced from north America by the Victorians. Populations have spread from southern England and Edinburgh/Glasgow. Grey squirrels carry a parapox virus which they are resistant to, but which is lethal for native red squirrels. Consequently, greys have displaced reds from much of Britain. Grey eradication programs are essential to protect red squirrels at the edges of their ranges.