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About American mink

Here you can find out more about the American mink - what it is, how it got here and why it is such a problem for native biodiversity in Scotland.
© Tomasz Wesolowski
© David Whitaker

What are American mink?

The American mink (Neogale vision or Neovison vison) is a small, semi-aquatic mammal, which occupies both freshwater and saltwater habitats and follows waterways, lake edges and coasts. Part of the “Mustelid” family, it is related to the otter, stoat, pine marten and weasel. It has rich, usually dark brown (sometimes black) fur, a narrow snout and a small white patch on the chin or throat (not always present). The tail is slightly bushy and approximately half the body length.

Mink are largely solitary and will hold their own territory – an average mink territory along a linear waterway is 1-3km for a female, male territories are larger, up to 5km, and may overlap several female territories. When in contact with other individuals vocal signals consist of squeaks, chuckles and squeals.

Mink are carnivores and eat a wide variety of prey including rabbits, water voles, rats, birds, eggs, fish and domestic fowl. They are an opportunistic hunter taking whatever prey is available at the time.

Mink breed annually, mating from February to April and with four to six kits born during April and May. Kits are weaned after eight weeks, are fully independent after 14 weeks and reach sexual maturity the spring after birth.

Download the mink ID sheet

How did it get here?

The American mink, as the name suggests, is native to North America, and was brought to the UK to establish fur farms in 1929.  There were many escapes, and deliberate releases, from these farms and mink were first confirmed as breeding in the wild in 1956.

The mink population grew and spread unchecked after these escapes and releases.  Although the Ministry of Agriculture Fisheries and Food funded a small eradication programme in 1964, this was wound up in 1970 when it was clear it was wholly inadequate. The fur farming industry in the UK was banned in 2000 under the Fur Farming (Prohibition) Act though many farms had closed in advance of this legislation.  Fur farms operating in the 1990’s were regularly attacked by animal rights groups and many animals were released from these activities.  However, it is believed that the large majority of mink released in this period, which were in effect domesticated, were quickly caught and that the existing wild population of feral mink stems from earlier escapes from the 1920’s.

The first Scottish fur farm opened in 1938 – mink escaped that same year.  The first report of mink breeding in the wild in Scotland was from 1962 in Aberdeenshire.  From this time a rapid spread of the mink population was seen between 1962 and 1974 – mainly dispersing from fur farms operating in the Firth of Forth and Grampian areas. By the 1980’s mink had started to be reported north of the Great Glen and were widespread across much of the rest of Scotland.

Mink are now widespread across the UK, with the exception of the far north of Scotland and some of the Scottish islands.
© J McAvoy

Problems caused by American mink

Once established in an area mink will spread naturally.  They are effective colonisers and easily cross waterbodies, including sea channels, to reach new locations and habitats.

They can have significant ecological impacts once established – largely through predation and competition. Mink are effective predators, eating birds & their eggs (native and domestic fowl), small mammals, fish, amphibians, shellfish and crustaceans.  The water vole and ground nesting bird populations are particularly at risk from mink predation.

Mink are thought to be responsible for the disappearance of the moorhen from the Hebridean islands of Lewis and Harris and are credited as being largely responsible for the 94% decline in UK water vole populations.

Mink can also impact economic activities such as fish farming, crofting, sports angling, game shooting and tourism.

The story of American mink in Scotland – by Scourie Primary School

Thanks to Scourie Primary School for this wonderful retelling of how American mink came to Scotland.

As part of our Primary School Film project, pupils from Scourie Primary created this short film. It tells the story of how American mink established in Scotland, all about the animal, the finding of the mink on Handa Island and the devastating impacts mink have on water voles.

Report a mink sighting

Please report sightings of American mink in our project area.

Report a mink sighting

History of mink control in Scotland

The American mink has, and is, frequently controlled on many estates and by many landowners. This can be locally effective but as mink removed will be replaced by new animals migrating from breeding taking place elsewhere is less likely to impact the overall population.  Mink control projects operating at scale are more able to counter these local migration activities.    

In 2004 one of the first mink control projects on mainland Scotland was initiated on the River Ythan in Aberdeenshire. Following years of mink eradication by a water bailiff along the river, zoologists at Aberdeen University noticed that the area was a stronghold for water voles, a species in serious decline in most other areas of the north-east.  From this the Ythan Rivers Project was set up to enhance and study mink control activities.  Following positive results this was scaled up across larger areas in North East Scotland.

In 2006 two large-scale coordinated American mink control pilot projects started – in North East Scotland and in the Cairngorms National Park (2006-2009), followed by another pilot – the North West Highlands Mink Control Project (2009-2011). Combining these areas and expanding south, the Scottish Mink Initiative launched in 2011.  It demonstrated that mink control could be coordinated at scale using a project based approach. As the Scottish Mink Initiative progressed local co-ordination and control was often delivered by fisheries trust staff rather than only by dedicated Project Officers (2013).

A review in 2015 looked back at the previous 10 years of American mink control in Scotland to evaluate activities and inform the development of the next phase – delivered through the framework of the Scottish Invasive Species Initiative. Download the SMI Review. (2015, Oliver, Mark: Scottish Mink Initiative review)

Of note from the Scottish Mink Initiative review:

  • Since large scale coordinated mink control began in 2006, around 1600 mink have been trapped and removed from northern Scotland.
  • The trends in long term mink abundance following control indicated that abundance will be more than halved following four years of control and reduced to <10% by year ten.
Download the SMI Review

Mink control today

The Scottish Invasive Species Initiative is working in partnership with ten fishery trusts and boards and over 350 volunteers to monitor for and trap mink across northern Scotland.

A network of around 600 rafts and traps, looked after by some 350 volunteers, extends across 43 river catchments providing comprehensive mink monitoring and trapping.

Read more about the mink control project

Further information