Mystery over grey squirrel in 'impossible location'
Conservationists have been alarmed by the appearance of a grey squirrel near Oban.
The animal has been seen on the Isle of Seil, one of Argyll's Slate Islands about 100 miles (161km) from the nearest other grey squirrels.
Greys are native to North America and classed as an invasive species in the UK because of the threat they pose to native red squirrels.
The Saving Scotland's Red Squirrels project said it was not known how the grey reached the area of Argyll.
Seil is connected to the mainland by a short crossing dubbed the Bridge of the Atlantic but grey squirrels have not been spotted previously.
Grey squirrels were first brought to the UK by the Victorians as an "ornamental species" in gardens of stately homes.
They can out-compete smaller reds for food and habitat, and some also carry a virus fatal to the native species.
Releasing greys in the UK was banned in 1930, but they have spread across England, Wales and large parts of Scotland.
Katie Berry, of Saving Scotland's Red Squirrels, said the Seil grey squirrel was in an area previously known to only have reds.
She said: "Seil is a very unusual location, in fact it's an almost impossible location for a grey squirrel to be in.
"We cannot say for sure how it got there. Potentially it may have got up via some sort of transport."
Ms Berry said it may have been carried to the area accidentally.
The nearest other greys are found just north of Helensburgh.
Saving Scotland's Red Squirrels has appealed for further sightings in Seil, around Oban and the surrounding areas.
Ms Berry added: "We very much hope it is a one-off."
The first grey squirrel was officially recorded in the Highlands 16 years ago.
It was believed to have got to the outskirts of Inverness on the back of a lorry carrying hay or straw bales.
