American Mink: A Good Invader

Invasive species are a common problem in ecosystems and the American mink are no exception. In order to understand whyAmerican mink make such good invasives, let's start with some background on the American mink!

The semi-aquatic American mink

Behavior:

• carnivorous members of the weasel family, Mustelidae 
• highly territorial
• results in solitary animals, except during breeding season
• Although the density of American mink in the wild varies depending on the quality amount of prey and habitat, there is "usually about one mink for each 50 acres of wetland habitat and three or four mink for each mile of good stream habitat" (Scottish Natural Heritage)
• Use anal glands to mark their territory
• spray when threatened, much like a skunk's, but less pungent (Fur Commission USA)

• semi-aquatic 
•  adapted to:
• diving (up to 16 feet deep) 
• terrestrial climbing
• found in wetlands and riparian habitats (Fur Commission USA) 
• hunt both aquatic and terrestrial prey (generalist predator)

Appearance:

• Adult male: about the size of a small house cat
• Females are slightly smaller than the males
• Long tail (~1/3 of body)
• partially webbed feet
• Thick, insulating fur coats 
• Because of the American mink's glossy, thick fur and a variety of fur colors, they have been favored for commercial farming (Fur Commission USA).
• tolerant of colder climates

Reproduction and Life History:

• Mating occurs for three weeks in February and March 
• Multiple matings for each female and male
• Sexual maturity is reached at 10 months

• Large litters of kits- commonly of 5 and 6
• Can live for up to five years, but about %50 usually die within the first year (Scottish Natural Heritage)

• fast generation rates
• "extremely prolific and capable of completely replacing their populations over three-year span" (Fur Commission USA)
• recover quickly from potential problems

Created by Noelle Le Tourneau
Information from (Kauhala, 2006) and (Bonesi et al, 2007)

According to Groom (2006), invaders have particular traits that make that make them successful invaders. Theses traits include being associated with human activity, previous history of invasion, related to an invader and having "weedy" traits, such as high rates of reproduction, high dispersal rate, tolerant of a wide range of conditions and high rates of reproduction.

The American mink have many of these traits, making it a perfect candidate for an invasive species. The bolded words above are some of the most important mink qualities that make it a good invasive species. Not only do these traits helped the American mink spread throughout Europe, but also make it rather difficult to eliminate them from the wild.