A BUFFER zone vital to the survival of the red squirrel has been extended to slow down the migration of greys towards the Scottish border.

The zone has been extended west from Kielder Forest - the largest red squirrel reserve in the country - to cut off the land gap in Cumbria between the forest and the Solway Firth.

Buffer zones are a key part of efforts to protect reds from encroachment by the greys, introduced into the UK from North America in the 19th century. They provide a focus for grey squirrel control around 17 specially designated red squirrel reserves. Now for the first time Forestry Commission grants will be available in the extended area covering 50 square miles to support land managers in tackling the spread of the greys using humane traps and methods.

Brendan Callaghan from the Forestry Commission said: “Joined up thinking and action is the key to safeguarding the future of reds in northern England and the Scottish borders. "We know that the Cumbrian greys have a much higher incidence of carrying the pox virus, which is deadly when passed onto 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.” Between 60 and 80 per cent of grey squirrels in Cumbria typically show antibodies for the squirrel pox virus when blood tested.

This means they have been exposed to the virus and may be carriers. T he virus was not present in greys in Scotland until very recently. The first death of a red squirrel in Scotland due to the virus was in May 2007 near Dumfries.

The Kielder Forest reserve is home to around 60 per cent of England’s remaining red squirrels. The Forestry Commission has altered its design plans for the woodland – the largest in England – which will see only small-seed broadleaf trees planted in addition to conifers.

Reds enjoy a greater competitive advantage in this kind of habitat over the greys.