Mink have a few characteristics in common with foxes. Both are pretty to look at and thus benefit from urban sentimentalism; both have taken advantage of opportunities offered by misguided human activists to expand their populations all over the UK; both are pests; both have a reputation for killing more than they need to eat; neither is kept in check by another natural predator.
The red fox is a UK native which has benefited from man having first wiped out the wolf and then banned his fellow men from forms of fox-control that they seemed to be enjoying too much.
The mink is an American import deliberately released from captivity first by activists and allegedly later by fur-farmers when their industry was outlawed.
Arguably the latter may turn out to have been the more disastrous of these two human interventions.
Mink have devastated the UK water vole population, which has declined from around 8 million in the 1960's to a figure possibly below 100,000 today.
Being semi-aquatic, mink are able to colonise Scottish islands which are breeding grounds for vulnerable seabirds including the puffin. On the mainland they are a threat to waterfowl and other ground-nesting birds, fish and domestic pets.
The Scottish Mink Initiative, launched in 2011, aims to remove breeding mink from the north of the country.
Why am I interested? Because this week I'm pretty sure I saw one of the little perishers beside a branch of the Culloch. Almost black, with just a sprinkling of lighter guard hairs, it was below me on the bank, trotting along until it entered a hole beside a pond.
By its movement, I thought at first it was a little cat; then I realised its legs were only half cat length and its head was so streamlined with its body that I could not tell where one began and the other ended. It was much too big for any of the smaller mustelidae such as stoats or weasels, more the size of a polecat or pine marten. The combination of the colour and the waterside habitat persuaded me it was probably one of the foreign invaders.
As the bean goose flies, this sighting is a goodly distance away from the breeding grounds of our local protected species, but since I gather mink will even take on gannets and swans there is no room for complacency here. So I've reported it to SMI and I await a response.