Don't let the soft coat fool you: Minks are formidable predators

Coming up a rise on the Fox River trail, I spotted it. Or, it spotted me.

A round little head with round little ears and a curious, if not cautious, stare.

I stopped. It stopped. I checked it out. It checked me out. Then, in a split second, it bounded silently into the vegetation and was gone.

This was one of several chance encounters I've had with wild American mink. Although mink are common and can be found in every county of Illinois, it's pretty cool to catch a glimpse of these illusive creatures. Their stealthy nocturnal habits, their impressive ecological niche, and their role in history are reasons enough to pay heed to mink in our area.

The American mink made its appearance on the mammalian scene in the Pleistocene epoch, some 1 million to 2 million years ago. Surviving the mass extinctions of the late Pleistocene, the American mink evolved in its niche as a fearless predator that would take on just about anything, including prey larger than itself. The mink is in the same family as weasels and skunks (the Mustelidae) and shares many traits with these relatives. Like weasels, mink have sharp carnivorous teeth (the better to bite prey with). They emit a strong musk (the better to repel an enemy with). They are long and sleek (the better to maneuver tunnels with). And their pelage, or fur, is legendary.

The mink's coat secured the mammal's role in history books and pocketbooks. Long utilized by indigenous peoples, mink fur became a valuable commodity as early as the 17th century when European newcomers - notably the French Voyageurs - established trade with American Indians. The Voyageurs traded blankets, clothing, utensils, guns and liquor for pelts.

Wild American mink have rich dark brown fur and a white chin. When prime in the winter time, mink fur is thick, durable, soft, and has a luxurious texture. The coat is one of many adaptations to a semiaquatic life. Guard hairs and underfur hairs provide waterproofing and insulation in cold water. The mink's guard hairs are "long and lustrous," as described by the United States Fur Commission. Lighter colored underfur hairs surround each guard hair. They are not as long as the guard hairs and their main function is to retain heat. Mink in the far north have thicker underfur than mink in our area.

Despite their sleek beauty, these 2-pound, 24 inch long creatures are aggressive and formidable predators. Primarily denizens of shorelines, mink will take on just about any creatures along lakes, ponds, and streams. According to the Illinois Department of Natural Resources, mink in Illinois consume a carnivorous diet of "frogs, mice, rats, fish, rabbits, crayfish, birds ... and muskrats."

Mink will travel inland and use their keen sense of smell in pursuit of rabbits and squirrels. Even though these prey are much larger than mink, they are easily taken down with a fatal bite to the neck. The mink will drag the prey back to the den for storage. Known for surplus killing, the mink may or may not eat all of its cache and some of it may spoil.

Mink are decidedly not good at sharing. A male will not tolerate the presence, let alone the sight, of another male, and male-to-male interactions can be vicious. Each male mink establishes a large territory, "as much as 2.5 miles of stream habitat or about 2,500 acres in wetland habitat," according to the United States Fur Commission's report on mink biology.

Mink are no slouches when it comes to patrolling their territory. Males vigilantly cruise around areas as large as five square miles.

Mink are superb athletes. With semi-webbed feet and waterproof fur, they are skilled swimmers. According to the Illinois Department of Natural Resources, mink can swim at depths of 50 feet. They are equally adept on land, where they travel by walking or bounding. Each bound is 10 - 24 inches in length - not bad for an 24-inch long animal with really short legs! Not only do they bound like Olympic long jumpers, but they do so at speeds of 7 - 8 miles per hour. To top off their list of physical feats, mink are good tree climbers and will take to the trees whenever the situation calls for it. Like squirrels, mink can jump from tree to tree, and they descend head first.

Mink are active at night throughout the year. In the extreme cold of winter, mink will seek shelter in dens along rivers and streams. They do not hibernate; they wait out the storms and then resume hunting for prey. The dens they occupy are usually foreclosures of muskrat or beaver dens - these mammals having become mink food.

Mink are solitary mammals and work entirely on their own. Only when rearing their litters of two to seven pups in May do mink interact as a family group.

As predators American mink are integral in the ecology of our riparian and wetland areas. They control rodent populations in and around wetlands and rivers. They are occasionally prey themselves for Great Horned Owls and coyotes.

The American mink is not so well appreciated, however, in other parts of the world. When the popularity of mink fur skyrocketed in the early 20th century, mink farming was established to meet the demand here and abroad. American mink were taken to Europe and Russia for hunting and fur farming.

Like many species outside their natural range, the American mink has become an ecological nightmare in Europe. Interbreeding of feral American mink with European mink has led to the decline of the latter. Feral American mink have also wreaked havoc on birds and small mammals in England and continental Europe. The drastic decline of the endangered Water Vole in Great Britain is directly linked to the American mink.

"They are now considered vermin in much of Europe," reports the online Science Daily, "and are hunted for the purpose of wildlife management."

Here on their home turf, the wild American mink population is stable but faces the usual challenge of habitat loss and degradation. The Illinois Department of Natural Resources emphasizes habitat protection and restoration as "the most important management practices for sustaining healthy populations." In most states, including Illinois, there is a legal trapping season for mink. Trapping regulations are in place to protect the populations from overharvest.

The Forest Preserve District of Kane County's comprehensive natural areas management program ensures quality habitat for mink and its wild neighbors.

As you're walking the forest preserve trails along the Fox River or its tributaries, keep a look out for these sleek creatures. You may be lucky enough to see one poking up its head through riverside vegetation, or diving without a splash into the water.

• Valerie Blaine is a naturalist with the Forest Preserve District of Kane County. You can reach her at blainevalerie@kaneforest.com.

<p class="factboxheadblack">Mink facts and lore</p> class="News">• The scientific name for the American mink, Neovison vision, is derived from the Latin word visor, which means "scout." If you do catch a glance of a wild mink, you may see it rise up on its hind legs to "scout" the area.</p> <p class="News">• Over 80 percent of minks in North America today are raised on farms for their fur.</p> <p class="News">• Mink oil comes from the fatty layer just under the skin. Industrial grade mink oil is commonly used for waterproofing and conditioning leather. A cosmetic grade of mink oil is also produced. This oil is highly touted for face and body. Proponents of cosmetic mink oil claim that "it enables the skin to re-moisturize itself by trapping moisture from the lower cell layers. The supreme softness, smoothness and moisture-retaining properties imparted to skin are believed to be due to the special ratio of glycerides contained in mink oil. Many users rave that it helps prevent fine lines and wrinkles, works wonder in hair products, and that it also works as a soothing treatment for sunburn."</p> <p class="News">• Typical of members of the weasel family, mink produce musk in anal scent glands. Although not as offensive as skunk musk, mink musk will assault your olfactory senses enough to make you run the other way. Among fellow mink, however, the musk is an important tool in marking territory. Mink can spray their musk much like skunk, and this chemical warfare keeps enemies (like you) at bay.</p> <p class="News">• What's the real reason that mink stink? Anthropologist James Mooney recorded this Cherokee story about the mink: "The Mink was such a great thief that at last the animals held a council about the matter. It was decided to burn him, so they caught the Mink, built a great fire, and threw him into it. As the blaze went up and they smelt the roasted flesh, they began to think he was punished enough and would probably do better in the future, so they took him out of the fire. But the Mink was already burned black and is black ever since, and whenever he is attacked or excited he smells again like roasted meat. The lesson did no good, however, and he is still as great a thief as ever."</p>