The ferret (Mustela putorius furo) is the domesticated form of the European polecat (Mustela Putorius), and a member of the Mustelidae family, a group that includes weasels and stoats (for more information, see below).
They typically have brown, black, white, or mixed fur. They have an average length of 51 cm (20 inches) including a 13 cm (5 inch) tail, weigh about 1.5–4 pounds (0.7–2 kg), and have a natural lifespan of 7 to 10 years. Ferrets are sexually dimorphic predators with males being substantially larger than females.
Being so closely related to polecats, ferrets easily hybridize with them, and this has occasionally resulted in feral colonies of polecat-ferret hybrids that have caused damage to native fauna, especially in New Zealand. As a result, some parts of the world have imposed restrictions on the keeping of ferrets.
The Ferret Family Tree
Ferrets are members of the Mustelidae or Weasel family, a diverse and largest family of the carnivores. Mustelids vary greatly in size and behaviour, from the smallest weasel to the giant otter.
As well as our beloved ferrets, their most common relatives that you could see in Britain are the weasel, stoat, pine marten, badger, polecat and otter.
Elsewhere in the world, other relatives include the mink, wolverine, ferret-badger, tayra, grison and a whole host of badgers, otters, martens and weasels!