A SLINKING black form makes its way along the far bank of the River Devon near Alva, so I brought the creature into focus with my camera.

It was an American mink, and as I examined the animal through my camera lens, there was no denying that this animal was rather attractive with its cute weaselly face, little white chin and thick-furred body.

Of course, the flip-side is that mink are not native to our shores – they hail from North America – and are descended from fur farm escapees from several decades ago.

As such, mink are universally detested by river managers and conservationists because of the havoc they wreak upon native wildlife.

They will take waterfowl and their chicks and eggs, prey upon trout, and are more than capable of destroying vulnerable sand martin colonies.

They are also adept climbers, and on at least two occasions in the past, I have spotted a mink up in the branches of riverside alders, so there is every possibility they plunder the tree nests of birds, too

Mink are also the villains when it comes to the demise of our water vole populations, which have plummeted by more than 90 per cent in recent times.

The mink is a natural carnivore, and it is easy to demonise it, which is wrong, for the animal is no fiercer or more of a villain than any native fox, otter or stoat.

The mink is only doing what evolution has made it to be. It is not the mink's fault it is here; it is entirely ours, and just one example of many that illustrates our inherent capacity to interfere with nature to the detriment of the environment.

The problem now is that the pace of human-aided colonisation of non-natives, including plants such as Himalayan balsam has gathered real momentum over the last few decades – and experience tells us that even the slightest tinkering can have the most undesirable and long-lasting environmental impacts.