HAVE you seen the American mink inhabiting the banks of the River Avon in Bradford on Avon?

The little animal – described as an “invasive species” by the Canal & River Trust, the charity that looks after the UK’s waterways – is part of the same family that also includes weasels, otters and ferrets.

It has been spotted chasing out rats from the debris and brambles close to Bradford on Avon’s ancient town bridge.

One resident who has seen it, Matt Cooper, said: “I had heard from many sources that there was a resident mink that lived on the River Avon and yesterday I finally caught sight of it. Incredibly, it was rooting around the brambles near the town bridge and chasing rats out.”

The animal is not a native to this country. American mink first arrived in Britain in 1929, but only in commercial fur farms.

They were first reported to be breeding wild in the UK in 1956, as a result of escapees and deliberate releases. Today it is virtually impossible to estimate the number of mink living in Britain's waterways.

The CRT says: “Mink numbers have increased rapidly in the last 30-40 years, and they are now common and widespread. They are semi-aquatic and are frequently encountered on our canals and rivers.”

“Close up, the American mink resembles something between a small cat and a ferret. They have a dense coat of deep brown fur, which often leads to cases of mis-identification with the native otter.

“However, otters are shy animals unlikely to be seen during the day, quite unlike their confident American cousins who will wander the waterways at all hours.

“Mink are also smaller and slimmer than otters, which makes it easier for them to hunt burrow-dwelling prey such as water voles.”

They are thought to be one of the causes of the sharp decline in the water vole population in the UK since the 1960s and 1970s as mink numbers increased in the wild.

The Trust added: “Unless some areas are kept free or relatively free of mink, it’s thought that the water vole will become extinct in much of Britain within a few years.

“We support targeted control of American mink to protect our waterways, as well as for the conservation of water vole populations.

“Mink control will protect our considerable investment, in recent years, in habitat improvement for water voles across the network.”