11002-22113 Feral ferret (Mustela putorius furo) female with seven newborn young in den. Adult female ferrets are only half the weight of males. This great size difference in the sexes has led to great gender differences in diet: male ferrets prey more on rabbits, females more on rats. In Northland, following the collapse of a struggling ferret fur-farming industry, many farmers went bankrupt and simply released their animals into the wild which has resulted in a dramatic decrease in kiwi in Northland. Ferrets are one of only two predators (the other being dogs), capable of killing adult kiwi.
From New Zealand Mammals