Grey squirrel  (Sciurus carolinensis)

Although a familiar mammal in many parts of Great Britain, the grey squirrel is non-native, having been first introduced from the eastern USA in 1876 (3). It is responsible for the decline in populations of our native red squirrel (Sciurus vulgaris) (3). The introduced species is larger than the red squirrel, has largely grey fur with touches of russet-brown, and white underparts (2). Unlike the red squirrel, this species never has ear tufts (2). The sexes are similar in appearance (1).