Most Unwanted: Feral ferret
Mustela furo
Habitat: Terrestrial
Threat: Threatens protected bird species
Status: Established
The feral ferret is a recent introduction to the Irish mammal fauna. The exact date of introduction is not known but it was first recorded in the wild in 1986.
What is it
Mustela furo are the domesticated form of the European polecat (Mustela putorius). Both species are not indigenous to Ireland. Ferrets follow the typical body form of the mustelidae family in that they have an elongated slender body. The colouration of the domestic ferret can vary considerably with season and between individuals. Albino/white, brown and grey/dark (wild European polecat colours) forms are known. The wild polecat type is seen more commonly in populations that have been wild for several generations. The face is often decorated with a dark mask in the form of cheek patches and bands.
Impacts
This species can have a detrimental effect on bird populations especially on off shore islands. It is also feared that ferrets can have a high impact on the breeding success of rarer bird species such as corncrake.
Where are they from?
This is the domesticated form of the European polecat Mustela putorius. They have been introduced to control rabbits and rodents in Britain and other parts of the world. They were also introduced to New Zealand and Britain for fur farms where they have escaped and formed wild poulations. Ferrets are increasingly becoming a household pet and in some instances have escaped or were released.
Where is it in Ireland
The species is currently established on Rathlin Island where it was introduced to control rabbit numbers. Stable population/s are known from the border counties of Monaghan, Fermanagh, Tyrone and Armagh. There is evidence that there may also be populations in Sligo and Waterford but this has not yet been verified.
How did it get here
The exact date of introduction is not known. It is believed that ferrets may have originally been brought to Ireland to help control rabbit numbers. It is also possible that the populations around the border counties are escapees from fur farms. Ferrets are also a popular pet species and escape from captivity of this type cannot be ruled out.
How can it spread
Natural dispersal and release by human.
What you can do
Do not introduce ferrets to the wild in Ireland or any off shore island.
Practice good animal husbandry and do not allow ferrets to escape.
Report all sightings.
Additional reading
Habitas Invasive Alien Species in Northern Ireland
