According to a study by Alison Thomas, a geneticist at Anglia Ruskin University in Cambridge, the black squirrel made up almost half the rodent population in some areas at the beginning of 2008.
"The estimate is about 25,000 (black squirrels) today, but the black mutation gene has a dominant aspect which explains their rapid increase," she told AFP.
With a thicker coat and a higher level of testosterone than either the red or grey squirrels, the black mutants have been dubbed the "super-squirrel" and are proving more attractive to females -- ensuring their population flourishes.
