Red Squirrels are under threat in Britain
Conservationists in Cumbria are to place 1,000 traps along the border with Scotland in an effort to stem the northward spread of grey squirrels.
The move is aimed at preserving numbers of native red squirrels, which have dwindled since greys were introduced into the UK in the 19th Century.
Sightings of reds have fallen in recent months in northern parts of Cumbria around Brampton, Carlisle and Longtown.
The Save Our Squirrels (SoS) project will monitor the situation.
Simon O'Hare, of Northumberland-based SoS, said: "The north of Cumbria is now a real problem, with sightings of red squirrels dropping off in a lot of areas.
"Anywhere approaching the Scottish border it is now a rare sight to see a red squirrel.
"The main problem is greys using river corridors and coming across from the Newcastle area."
The live capture traps will be monitored at least once a day and any red squirrels trapped will be released.
Greys carry a disease called squirrel pox, which is fatal for reds.
Last month three cases of the disease were found on the Queensberry Estate near Dumfries.