GUARDIANS of Poole Harbour's famous red squirrels have a contingency plan in place to protect them against the deadly virus carried by the greys.

Scientists have warned that England's population of reds could be wiped out within 10 years unless there is a cull of the introduced greys, which carry the parapox virus, but are immune to it.

While the smaller reds in the north of England are particularly at risk - declining up to 25 times faster in areas where the pox has been detected - Brownsea Island's cute Squirrel Nutkins are protected by the natural barrier of the sea.

However, this National Trust bastion of around 200 red squirrels, whose nature reserve is managed by Dorset Wildlife Trust, is taking no chances.

"We are concerned about it," said warden Abigail Gibbs. "We have got a plan that was drawn up to deal with any incidence of greys being brought over."

There will be a very warm welcome for any intruding grey that is spotted setting foot on the island. "Nobody moves until the squirrel is found and destroyed," she said. "They are around at Sandbanks. We do see quite a lot. It's potentially possible one could get on a boat and come over," she said.

She is keen to find a student to survey the island's squirrels and do some research into a health problem which is affecting them.

"They have this condition where they get what looks like a cauliflower ear and it affects their hands and feet," she said. "We think it's a mite infestation."

September and October is the best time to see the reds on the island, which is an increasingly important outpost as mainland populations are threatened.

The deadly disease kills red squirrels in two weeks and with no vaccine available the only effective option is to cull greys at entry points to England's 16 designated red squirrel refuges, said the team from Newcastle University and London's Queen Mary University.