Red squirrels are making a comeback in Perthshire and Fife after a five-year absence from the areas.

Evidence of their presence has been hailed as a sign of success in the territorial battle between the native red squirrels and non-native grey squirrels, which carry squirrelpox.

For decades, the smaller red squirrel has been losing woodland habitats to the greys, prompting fears about the species' long-term survival.

A survey by conservation charity the National Trust for Scotland (NTS) has found red squirrels have been spotted by staff at Branklyn Garden in Perth and Falkland Palace in Fife.

The sightings come after work was carried out to control the grey squirrel populations around these areas.

At NTS property House of Dun, in Montrose, Angus, staff are also logging many more sightings of red squirrels on trail cameras but they also filmed a grey squirrel for the first time recently, which the NTS says is of major concern.

Angus is proving to be a critical location in protecting the Aberdeenshire stronghold of red squirrels, which is why the Montrose sighting has caused worry among conservationists.

A squirrel census found there were red squirrels at 29 NTS properties and grey squirrels at 32.

NTS nature adviser Lindsay Mackinlay said: "The recent census of our properties has shown that red squirrels are holding their own, and even thriving in many cases.

"We've had some real successes in our Aberdeenshire, Perthshire and Fife properties, where we have seen the near disappearance of grey squirrels from places like Crathes and Drum after years of seeing them expand in numbers, whilst we have seen reds return in other places."

NTS said the situation for red squirrels is still far from secure as their non-native cousins continue to move into new areas and the harmful squirrelpox virus spreads.

Mr Mackinlay added: "Greys have expanded their range in some regions, particularly around House of Dun, beside Montrose, and they continue to threaten reds in Dumfries and Galloway.

"The current situation is stark and simple, greys are still here and with squirrelpox virus moving northwards with them, there is a very real danger for our red squirrels in some of our most beautiful properties, like Killiecrankie, Crathes, Threave and House of Dun, to name but a few.

"All these properties sit on the so-called frontline of grey expansion."

Hope for the red squirrels could be offered in the north west Highlands.

Mr Mackinlay said: "We are looking at our properties in the north west to see if they would be suitable for red squirrel introductions, and would encourage other landowners to do the same.

"This could provide a long-term refuge for red squirrels should grey squirrels and the squirrelpox virus keep heading northwards."