Wild mink are adaptable to a wide range of climates, and this species is far more common than most people realize. Efficient predators, mink are quick on land, skilled swimmers, and capable tree climbers. They are often found in habitat types suitable for muskrats, and they are often taken in traps set for muskrats. Mink are usually shy, but they can become bold when their curiosity is aroused. Mink are not sociable with others of their kind — except during the breeding season — and avoidance or fighting between mink is common.
Mink have 34 teeth, with four prominent canine teeth to help in the killing of prey species. Mink have rather long and supple bodies with relatively short legs. There are five toes on each foot that have partial webbing. Tails are fully furred.
Males are larger than females. Males are 20-30 inches long, and females measure 16-21 inches. Male weights exceed 3 pounds in many areas, and females usually weigh 1 1/2-2 pounds.
Mink fur is short and dense. Shades of color vary somewhat according to region and individuals. Most shades of color are chocolate to almost black. Patches of white fur are typical on the chins of most mink, and many mink exhibit patches of white fur on throats, chests, and bellies. These small patches are irregular in shape and vary from mink to mink. In some areas, occasional mink have a light colored and wooly underfur. This is evident on the lower backs of the mink. These pelts are referred to as "cotton" mink, and these pelts have lesser value.
Mink glands are present near the anal area under the skin of both male and female mink. Musk is sometimes released when the mink is excited or stressed. The odor is powerful and unpleasant.
Breeding occurs over much of the mink range during late February or early March. Males attempt to find several females during this short season. The males usually abandon the females after breeding takes place.
Females have one litter per year, usually raising about four young. Gestation times vary from 40 to 75 days due to a delayed implantation process.
Females raise their young entirely by themselves. Dens in abandoned muskrat dens, hollow logs, and rock piles are common. Mink do not usually dig their own dens, but they sometimes burrow into exposed muskrat and beaver lodges above the waterline for denning purposes. Many female mink seem to seek out secluded ponds or small streams with an abundant food supply and good protection to raise their young.
Male mink have territories or ranges much larger than females. Males seem to be constantly on the move, covering miles in a single day. Females often restrict their travels at night to 20 acres or so in marsh habitats, and they seldom travel farther than 100 yards up- or downstream from their dens near rivers or creeks.
The males seem to have routes that might cover 25 miles or more. These males have any number of dens that they use when they are in the area or feel like resting. It appears that males commonly store food in some of these dens for later use.
Many trappers think males return from their travels about once a week and follow nearly the exact same route, crossing streams at the same places and investigating the same brush piles or undercut banks for food. Holes, hollow logs, rock piles, and brush piles interest many mink as protected places to hunt.
Length: 30 inches
Weight: over 3 pounds
Mating season: February and March
Gestation: 40-75 days
Life span: up to 7 years
Worn teeth are an age indicator
Mink are capable at trailing or stalking prey species, but it appears that they are usually opportunistic feeders that pursue prey after they surprise and startle the prey into flight. Mink hunt and travel mostly at night, but they are occasionally active during the day, especially just before storms or when it is raining or snowing. During periods of extreme cold or deep snow, mink seem to stay near their dens. At times, they will live in dens with underwater access and do the bulk of their hunting under the ice.
Mink kill a variety of prey species, including muskrats, crayfish, frogs, rabbits, fish, birds, snakes, grasshoppers, and water beetles. Mink often catch fish and have also been known to enter chicken houses and kill chickens.
Some individual mink appear to kill muskrats with regularity, while other individual mink do not appear to kill muskrats at all. A mature muskrat can surely give a mink a battle in a tight place or when cornered. Many mink seem to prefer easier, safer prey. However, muskrat seems to be a preferred food for mink, and virtually all mink will scavenge dead muskrats if they are hungry and the meat is fresh. They are capable of catching a muskrat in the water because they use all four feet for propulsion; the muskrat only uses its back feet for propulsion, with the tail acting as a rudder. Evidence suggests that mink prey heavily upon muskrats when muskrats are diseased. This may help prevent the spreading of these diseases to healthy individuals.
Mink are found from the edge of the tundra across Canada and Alaska to Florida, Texas, and California. This species might be absent in Arizona.
Mink are usually shy and avoid humans, but at times, they exhibit boldness when their curiosity is triggered.
Although mink are sometimes found traveling or living far from water, most prefer the habitats found along the shores of streams, lakes, marshes, canals, and ponds. Mink usually hug the shores as they travel and prefer staying on dry land when they have a choice. At times, an obstacle such as a protruding rock or log may cause the mink to detour into the water.
Mink are preyed upon by owls, fox, coyotes, bobcats, and dogs. Internal parasites include flukes, roundworms, and tapeworms. External parasites include fleas, ticks, and lice. Mink are vulnerable to distemper, parvo enteritis, encephalitis, and rabies.
A 7-year-old mink is considered old, and worn teeth are an indication of age.