Outer Hebrides Biological Recording  Outer Hebrides Biological Recording

Invasive Non-native Species - Terrestrial Animals

American Mink

Information and Identification Sheets:

American Mink Neovison vison

First introduced for fur farming in the 1920s the American Mink, Neovison vison, became established in the wild in the 1950s following escapes and deliberate introductions. The first phase of the Hebridean Mink Project was started in 2001 with the aim of eradicating mink to to protect the internationally important ground nesting and migratory birds. This removed mink from North Uist, Benbecula and South Uist and reduced their numbers significantly in South Harris. This was followed by phase two which aimed to establish a buffer zone for the Uists by concentrated trapping first on South Harris and then gradually moving north and west through Lewis towards Ness.

The eradication programme is now almost complete and monitoring is currently being carried out to ensure that no mink re-establish in areas that have been cleared and the final few individuals are caught.

The importance of continued surveillance is illustrated by the immediate response of the trapping team to reports of mink on North Uist in 2015. Small numbers have been trapped and work will be continuing to ensure that mink will be completely eradicated from the islands.

Feral Ferret

Information and Identification Sheets:

Feral Ferret Mustela putorius furo

The ferret, Mustela putorius furo is descended from the European polecat. It is a large mustelid, larger than a stoat and varying in colour from dark brown to yellowish-white. Some animals show the polecat's masked face and distinctive coat pattern.

Ferrets were originally introduced into the Outer Hebrides to catch rabbits and a feral population has become established from escaped and deliberately released animals.

They will take domestic poultry, but there biggest impact is on ground nesting birds. The significance of the level of predation on rare bird species is unknown.

New Zealand Flatworms

Information and Identification Sheets:

New Zealand Flatworm Arthurdendyus triangulatus

The New Zealand Flatworm, Arthurdendyus triangulatus, probably arrived in the UK in the 1960s with specimen plants sent from New Zealand to a botanic garden. New Zealand Flatworms prey on earthworms, posing a potential threat to native populations. Their presence could have an impact on native species dependent on earthworms and could have a localised, deleterious effect on soil structure.

New Zealand Flatworms have been introduced into the Outer Hebrides and we have produced an advisory leaflet for local gardeners to raise awareness and stop their spread.