American Mink (Mustela vison)

<strong>American</strong> <strong>Mink</strong><br />

Species Description<br />

Scientific name: <strong>Mustela</strong> <strong>vison</strong><br />

AKA: Feral <strong>Mink</strong> and Minc (Welsh)<br />

Native to: North America<br />

Habitat: Aquatic habitats, including coastal, but<br />

mainly rivers and lakes<br />

Established throughout the UK. Mostly nocturnal or active at<br />

dusk (but may be active at any time). Introduced for fur farming<br />

in the 1920s, with a peak in the 1960s. Established in the<br />

wild as a result of escapes and deliberate introductions. First<br />

recorded breeding in the wild in 1956. Has significant impact<br />

on native wildlife, especially water voles, sea birds, domestic<br />

fowl and fish on which it predates.<br />

<strong>American</strong> mink is listed under Schedule 9 to the Wildlife and<br />

Countryside Act 1981 with respect to England, Wales and<br />

Scotland. As such it is an offence to release or allow the escape<br />

of this species into the wild.<br />

For details of legislation go to www.nonnativespecies.org/<br />

legislation.<br />

Key ID Features<br />

Body length<br />

30-47cm<br />

Glossy dark<br />

brown/black fur<br />

Tail length 13<br />

-23cm (about<br />

half body<br />

length)<br />

www.nonnativespecies.org<br />

Produced by Sophie Smith, Olaf Booy, Max Wade and Vicky White of RPS<br />

Usually has white patches on chin<br />

and throat (small amounts of white<br />

fur may be present on the upper lip)<br />

Scat can be<br />

solid (as<br />

shown) or very<br />

loose to liquid<br />

Tracks may form paths leading to water,<br />

occasional signs of tail dragging in mud<br />

Found in conspicuous<br />

sites<br />

Usually contains fur,<br />

pieces of bone and feather<br />

6-8cm long<br />

Strong<br />

pungent<br />

odour<br />

Sausage-like, but<br />

twisted and drawn<br />

out to a point<br />

2.5–4cm

---

Similar Species<br />

<strong>Mink</strong> are very similar to polecats but can be distinguished by the white<br />

markings on their face. While ferrets are also similar size and shape,<br />

they are usually very different in colour. Note that polecats and ferrets<br />

may interbreed producing offspring with intermediate characteristics. The<br />

only other species that may be confused with mink is otter, however this<br />

is easily distinguished by its considerably larger size as well as through<br />

field signs such as tracks.<br />

<strong>Mink</strong><br />

For comparison<br />

Polecat<br />

Native<br />

(<strong>Mustela</strong> putorius)<br />

White above upper<br />

lip creates a mask<br />

Otter<br />

Native<br />

(Lutra lutra)<br />

Much larger- twice the length and<br />

7-10 times the weight (1-1.2m long<br />

from head to tail, 7.5-10.3kg weight)<br />

<strong>Mink</strong> generally do<br />

not have white<br />

above the lower lip<br />

White tips to ears<br />

<strong>Mink</strong> are elusive and field<br />

signs are therefore useful<br />

to aid identification,<br />

however these will not<br />

allow you to distinguish<br />

between mink and<br />

polecat<br />

Tracks<br />

Redrawn from Sargent and<br />

Morris (2003)<br />

Pale upper and<br />

lower lips, pale<br />

cheek patches<br />

Chestnut brown fur<br />

with paler underside<br />

Distribution<br />

Widespread throughout Britain, limited<br />

mainly to aquatic habitats, population<br />

stable<br />

Source: NBN Gateway. Check website<br />

for current distribution<br />

Polecat <strong>Mink</strong> Otter<br />

Note that mink and polecat prints are identical<br />

Approx 1m<br />

Size and Shape<br />

Otter<br />

Polecat<br />

Photos from: Johnny Birks, Olaf Booy, Rick Leche, Mary Frances Loggans, Martyn Nicholls, Les Willis<br />

1cm<br />

<strong>Mink</strong><br />

References and further reading:<br />

Bang, P and Dahlstrom, P (2006) “Animal Tracks and<br />

Signs. OUP Pocket Guide Series”. Oxford University<br />

Press<br />

MacDonald, D (2005) “Collins Field Guide to the<br />

Mammals of Britain and Europe”. Harper Collins<br />

Sargent, G, and Morris, P, (2003). “How to find and<br />

identify mammals”. The Mammal Society<br />

Sterry, P (2005) “Collins Complete British Animals”.<br />

Harper Collins