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Thursday, June 28, 2012

The Slinky Mink

This is the second in a series of articles on the ten members of the weasel family that are found in Michigan.  We have covered the three smallest members of mustelids, now we will look at the two aquatic weasels:  this issue the mink, and next issue, the otter.
Some predators are highly specialized, honed by evolution to efficiently hunt certain prey in distinct habitats and situations.  And then there’s the mink (Mustela vison).  The sleek, dark- bodied weasel is about as versatile as predators come – taking a wide variety of prey on land and water, day or night.  If a mink played baseball, it would be the utility player who could step in at almost every position. 

Mink are found throughout North America except in the extreme northernmost reaches of Canada and the arid southwestern U.S.  Much larger than the short-tailed and long-tailed weasels (see the March - April 2012 issue of The Wildlife Volunteer), adult males reach 28 inches in length and can weigh up to 3.5 pounds.  Females are smaller, but are still big enough to prey on muskrats, rabbits, small woodchucks, chickens, a host of smaller animals, and birds’ eggs.

A mink’s foot has five toes that are slightly webbed and with semi-retractile claws.  That combination lets the animals swim well and keep its claws sharp enough to grab fish and other slippery prey.
Mink can dive 15 feet and swim fast enough to catch muskrats underwater as well as in muskrat houses and burrows.  They stalk lakeshores, river banks, and wetlands, matching hunting times to prey availability.  This past winter, I watched a mink follow a lakeshore, then walk the edge of open water on ice in broad daylight far away from cover.  Yet, mink also frequently hunt at night, slinking in and out of thick brush, cattail stands, log jams, or rock piles.
Mink kill the same way as the smaller weasels with bites to the head or neck.  The prey is either eaten on the spot or carried to a den, often a former muskrat or beaver burrow, or a hollow log.
Like all other weasels, mink will fight viciously with each other or to defend themselves against foxes, bobcats, coyotes, owls, and hawks.  Mink exhibit delayed implantation with actual pregnancies occurring 9 to 45 days after mating.  Young are born blind and fur-less, usually in spring.  The number per litter is highly variable; just one or two when food is scarce, and as many as ten when food is abundant and other environmental conditions favorable.  Of course, many predators take young mink, especially when they are still in nests.
Mink are trapped in Michigan, but because of a long-term decline in the fur industry, most of the fabled mink stoles and coats now come from animals raised on ranches.  There they breed mink to yield some fur colors much lighter than that of wild mink.
Mink can be secretive, but at times seem almost oblivious to the presence of a human.  I’ve gotten within a few feet of mink several times.  A few of the animals seemed to see me, but did not run or hide.
Many long-time fishermen and duck hunters have stories about close encounters with mink bent on stealing fish, raiding the bait bucket, or grabbing a duck left aside during a hunt.  And as with most other weasels, farmers tell of mink raids on chicken pens far from water.
Occasionally, mink draw the wrath of landowners by stuffing drain pipes full of excess prey.  Dr. James Harding, a biologist at Michigan State University, remembers having his sump pump pipe plugged with dead frogs stored there by a mink.
Currently, YouTube has video of mink attacking prey including a young swan much too large for the mink to kill, trying to steal trout off a fisherman’s stringer, and other antics in full view of one or more humans.  The last couple of years, a mink family has been a minor tourist attraction on a Lake Michigan breakwater in the City of Ludington in Mason County.  In spring, the young mink dart in and out of the large stones just a few feet from walkers, bringing to mind the song, “Pop Goes The Weasel.”
Dr. Patrick Rusz
Director of Wildlife Programs – Mink Stealing Rainbow Trout (Good Close Action) – Mink Attack on young swan

1 comment:

  1. Im on the shore in Racine, WI. See them once a week.