Bibliographical reference – how to cite this fact sheet: Birnbaum, C. (2006): NOBANIS – Invasive Alien Species Fact Sheet – Mustela vison. – From: Online Database of the North European and Baltic Network on Invasive Alien Species – NOBANIS www.nobanis.org

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Iceland
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.672.4593; http://nobanis.org/files/factsheets/mustela_vison.pdf

Species identification M. vison is a medium-sized carnivore. It has an elongated body with relatively short limbs, a typical feature of the weasel family (Mustelidae). Another characteristic feature of the family is its sexual dimorphism, i.e. males and females differ greatly in body characteristics. The males often attain a head and body length of 34 to 45 cm and a weight of 1500 g. In some localities animals are generally smaller, e.g. in Iceland the average weight of adult males has been observed to be only 1200 g (Róbert A. Stefánsson, pers. comm.). The females are much smaller, having a head and body length of 31 to 38 cm and a weight of 400 to 800 g (cf. Stubbe 1975, 1988, 1993). The coat is dark brown, often with white markings in individual patterns on the ventral side. Various color mutations have been bred into the species, among them black, Aleutian, Palomino, pastel, pearl, various hues of gray, and even white (Stubbe 1993). The natural brown fur sometimes becomes bleached, especially on M. vison in coastal habitats. Although Mustela vison is from its appearance quite similar to Mustela lutreola, there is one feature that helps to differ between them: the upper and lower lip and the chin of Mustela lutreola is usually white while Mustela vison does not have this feature (Maran 2002).