Although a familiar mammal in many parts of Great Britain, the grey squirrel (Sciurus carolinensis) is non-native, having been first introduced from the eastern USA in 1876. It is responsible for the decline in populations of the UK's native red squirrel (Sciurus vulgaris). Grey squirrel was also brought to Australia, but it was eventually exterminated. The introduced species is larger than the red squirrel, has largely grey fur with touches of russet-brown, and white underparts. Unlike the red squirrel, this species never has ear tufts. The sexes are similar in appearance.