American Mink – Neovison vison

Serious attempts have been made to remove mink from river systems where water voles might be favoured, and from offshore islands, especially the Outer Hebrides, where ground-nesting birds should be abundant (in the absence of all the usual terrestrial predators). Effective control is based on the use of mink rafts; these have clay floors, enclosed in a tunnel, which reveal when mink are present; the clay tray can then be supplemented by a trap, and any mink caught can be shot. In the Outer Hebrides, a cage-trapping campaign has already eliminated them from North Uist.
Identification
Plain chocolate brown/black fur (black when wet) with a white chin. Variable white patches on throat, chest and groin. Fluffy tail about half the length of the body. Similar size to polecat but much smaller than Eurasian otter, as only 60cm in length. Mink swims with about half the body above the water. Face has a slightly pointed muzzle.
Field Signs
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Footprints: American mink footprints can be found in sand, mud and snow alongside rivers and streams. They are five-toed and are about 3-3.5cm in width and 2.5-4cm in length.
Droppings: They often contain bones and fur and are long and twisted in shape, with tapered ends. Approximately 6-8cm long, 10mm thick. Colour: greenish, black, brown. Smell: foul, like burnt rubber and rotten meat, very unpleasant.
Confusion species
Pine marten (Martes martes)
All dark brown except for a cream/yellow bib down the throat and chest, whilst american mink is usually all dark brown, with a white chin. Ears are proportionately smaller and much less conspicuous than pine marten’s.
Otter (Lutra lutra)
Mid-brown coat, lighter than mink’s dark brown coat. Otter also has paler underside which mink does not have. Long, muscular, tapering tail, whereas the mink’s tail is long cylindrical and fluffy. Otter has a broader muzzle and is larger than a domestic cat. Mink has a more pointed muzzle and is smaller than a cat.
Polecat (Mustela putorius)
The polecat is a very similar size to the american mink. Polecat generally has blackish fur with creamy underfur that shows through, with a dark bandit mask over pale fur on the face. Mink is usually all dark brown besides a white patch under the chin.