How Humans Have Made a Mess of Mink

It's possible you've heard of a mink, and it's also possible that the thing that pops into your head when you hear that word is Marilyn Monroe in a fur coat. But of course a natural fur coat is made of animal skins; in the parlance of our times, a "mink" is a coat — an astronomically expensive one — made of the pelts of a type of weasel called a mink, which is raised in captivity for the purpose of providing rich people with cozy outerwear.

But what makes mink fur such a desirable material for glamorous bolero jackets — and why we've been trapping and wearing mink since at least the 11th century — is also what helps a mink survive in the wild. Two species of mink exist on planet Earth today — one other, the sea mink (Neovision macrodon), is now extinct due to a couple of centuries of persecution by fur trappers. Both surviving species have thick, soft, water-repellant fur (as did the extinct mink).

Both the American mink (Neovison vison) and the critically endangered European mink (Mustela lutreola) are semi-aquatic, sticking close to waterways — streams, rivers, wetlands, lakes, etc. — where they can find all the foods they like to eat best: frogs, birds, clams, eggs, aquatic insects and small mammals like rabbits and mice. They love slinking around rocky riverbanks in the early morning and evening and, during the heat of the day, repairing to their luxurious multi-chambered burrows lined with grass, fur and feathers. They're extremely tricky to trap because they're smart and suspicious, but we humans are, if nothing else, great at devising ingenious ways of killing stuff, so we've managed to put mink in a precarious existential position.

The American mink is doing pretty well in the wild: They can be found in parts of every state in the U.S. except Arizona, and aren't uncommon throughout their natural range. In fact, they are also not uncommon in other places in the world, including the traditional range of the European mink, which is native to Europe and Eurasia.

How the American Mink Immigrated to Europe

American mink were brought to Europe in the early 20th century in order to satisfy the European passion for fur garments. By the 1950s, at least 400 registered mink fur farms existed in the U.K. alone — all stocked with American mink, the species of choice for the fur industry, since they are larger-bodied than the European species and their coats are a bit longer and denser.

But it's predictably difficult to hold a weasel captive, and the American mink that had spent a few generations on European farms escaped and became naturalized citizens of Europe. And it turns out they were very aggressive towards the locals — feral farm-raised mink and their offspring began killing European mink and their kits.

"It is important to consider that feral American mink is not the same as native American mink in North America," says Dr. Iñigo Zuberogoitia, a researcher in the Department of Environmental Studies at Estudios Medioambientales Icarus in Logroño, Spain. "Feral American mink is like a 'new' species created by humans after decades of breeding in captivity — they do not behave in the same way as wild American mink in their native range."

An example of altered behavior in feral American mink in Europe has to do with territory — wild males of both species are normally very territorial and don't put up with other males sharing their area. Feral American mink, on the other hand, don't seem to mind sharing space with each other.

"In this way, in rivers where it once was possible to find one European mink male and between 3 and 4 females, you can now find as many as 30 American mink," says Zuberogoitia. "The predation pressure in the area is extremely strong."

As a result of this ecological debacle, the European mink is one of the most endangered animals in Europe — the population has plummeted by over 50 percent in the past decade, and although competition from the American mink certainly isn't helping matters, European mink are also hunted by humans and have long been the victims of human-driven habitat loss. Activists and researchers are working against the clock to save the species.

Meanwhile, mink farms flourish worldwide. Mink accounts for 85 percent of the global fur trade, and fur is still a popular material in haute couture (in 2016, two thirds of major fall fashion week shows worldwide included fur). The mink fur industry in the United States grosses around $300 million a year (there are farms in 23 states), but a few European countries outstrip America's farmed fur production. Meanwhile, the mink fur business is booming in China, a country with a lot of newly wealthy citizens in the market for luxury items, coupled with very few animal welfare regulations.