The following is an excerpt from "The Mighty Mink" by Ty Smedes from the January/February issue of Iowa Outdoors magazine. Order back issues or subscribe now.
Mighty Mustelid
The American mink is a mustelid and belongs to the weasel family. Mustelids include 65 species (and 25 genera) of weasels, badgers, ferrets, fishers, martens, otters, minks, wolverines and more. The earliest mustelids appeared during the early Oligocene Epoch, roughly 35 million years ago.
Built much like its larger relative the otter, the mink has a long, sleek body about 2 feet long. It has short, stubby legs, a long neck, small ears and eyes and a long, thick tail. In fact, one third of the mink’s length is tail. It has brown to black fur with white on its chin and throat. Its fur is soft, thick and covered with oily guard hairs that make it waterproof.
This little mammal is an accomplished swimmer with slightly webbed feet to nab underwater prey.
Find Mink across Iowa from Mighty Rivers to Creeks and Marshes
Mink can be found in most of the United States and Canada, excluding Hawaii, Arizona and parts of several other western states. In Iowa, it makes its home near most any marsh or river, including even the tiniest meandering creeks. I have spotted them bouncing along the narrow creek that flows beneath our Urbandale driveway, and along the backwaters of Beaver Creek just northwest of Des Moines.
They love a marsh environment, and I’ve been visited by mink in the doorway of my duck blind. They have been spotted crossing from one island to another in the Mississippi River, and popping out of small culverts beneath suburban bike trails. Road-killed mink have even been spotted along the Des Moines freeway, near downtown.
A primarily nocturnal animal, they are most active at dawn and dusk to avoid human detection.
All for a Mink-Sized Meal
The mink is a carnivore, and preys upon mice, chipmunks, fish, snakes, frogs, crayfish and even muskrats and rabbits as large as itself. It kills prey by biting the neck, and sometimes stockpiles extra food in its den. It occasionally feeds upon carrion. Mink often use empty riverbank dens, abandoned by beaver or muskrat, or a hollow log. Its dens often have more than one entrance and are typically located close to water. It never uses the same den for long.
A mink spends a lot of time in or near water, hunting its next meal. It’s an excellent swimmer and can dive as deep as 16 feet and swim under water up to 35 yards. It’s a skilled tree climber and can jump from tree to tree, as well as descend trees head first.
Like the skunk, the mink sprays intruders with a foul-smelling liquid. However, unlike the skunk, the mink can’t aim its spray. When a mink is happy, it purrs like a cat. Males are very territorial, marking their home range with scent, and fighting other males that invade their space.
The Making of the Next Generation
Female mink reach sexual maturity at about one year, but males are not mature until around 18 months. Mating occurs January through April, with kits born April through June. The female uses delayed implantation, with fertilized eggs not implanting in the uterus or developing right away. Although embryo development takes just 30 to 32 days, gestation may span 39 to 78 days, becoming shorter during warm weather, with increased temperatures.
Females give birth to a litter of three to six young in a fur-lined nest. Babies are weaned when 5 to 6 weeks old, learn to hunt at about eight weeks and stay with their mother until fall. Their life-span is three to four years in the wild.