Tuesday, February 1, 2011

Our Mink Invade Scotland

We tend to think of invasive species as a one way trip into the US.  It actually works both ways.

American Mink- Click to enlarge-Wikimedia
A story on the BBC tells of the efforts to eliminate North American mink from the waterways of Scotland.  They were brought to the UK in the 1950's to be farmed for their fur.  They either were released or escaped into the waterways.  There they did what mink do best -  eat voraciously and make babies.  There are "now tens of thousands throughout the UK."

There are two varieties of mink, the American mink (Neovison vison) and the European mink (Mustela lutreola).  The European mink always has a large white patch on its upper lip, a variable feature on the American mink.

The American mink is larger and more adaptable than the European mink according to Wikipedia, and is out-competing its cousin. In addition, the American mink will breed with female European mink before their own males are ready to breed.  There are no offspring from the mating, but the females won't breed again that season, contributing to population decline.
These "predators have had a devastating impact on local river wildlife, affecting birds such as moorhens, coots, widgeon and teal, fish and most markedly water voles, which have declined by more than 95% over the last 50 years.  Conservationists say they are left with a stark choice: either leave the mink alone and allow the UK's native wildlife to continue to decline, or begin the colossal effort to remove them, however difficult this may be."  BBC
Since mink live along water,  authorities have developed an innovative method of trapping and eliminating them.  They use a small raft with a clay plate inside a box on the raft to record foot prints of the curious mink.  Once they have identified footprints, they place a live trap in the box to capture and then eliminate the mink.  The video shows the methodology which is being used by 186 volunteers.

Another BBC story outlines some of their other invasive species.  These include not only our shared threats such as zebra mussels, but also introduced gray squirrels which threaten their native red squirrel populations, and a giant Asian hogweed that has become widespread across the UK and can cause skin burns and blisters if its sap comes into contact with skin.

Another study has shown the "delayed legacy of invasive species."  Most of the invasive species that we confront today were introduced around or before 1900.  Given this time to develop and spread, you can only imagine what the side effects of our current globalized markets and burgeoning imports will have in 2111.

No comments:

Post a Comment