The red squirrel population is under threat from greys
Conservation chiefs have widened a "buffer zone" around a red squirrel reserve in northern England, in a bid to protect the species.
The site in Kielder Forest, Northumberland, includes the Cumbrian woods of Kershope and Spaedadam.
The extension cuts off the land gap between the forest and the Solway Firth, to slow down the migration of grey squirrels to the Scottish border.
These carry a pox virus, harmless to themselves, but fatal to red squirrels.
Buffer zones are a key part of efforts to protect reds from encroachment by their grey cousins, which were introduced into the UK from North America in the 19th Century.
Within them, Forestry Commission grants are available to support land managers in tackling the spread of the greys using humane traps and methods.
Brendan Callaghan, from the Forestry Commission, said: "We know that the Cumbrian greys have a much higher incidence of carrying the pox virus, which is deadly when passed on to the reds.
"Although there are greys on the Scottish side of the border, they don't carry the virus to anything like the same extent.
"That is why it makes sense to extend the Kielder buffer zone westwards to the sea to try and keep these grey populations apart which will also help efforts north of the border."