It appears that some red squirrels are starting to develop an immunity to a virus which threatens to wipe out the population. Britain's native red squirrels are now only found in on the Isle of Wight and Brownsea Island. They have been under threat from a killer virus which was introduced by the non native but much more common grey squirrels. Recently eight red squirrels have been found that had an immunity to the squirrelpox virus which threatens the species. The red squirrels that were found with the immunity had died from other causes but were clear of the squirrelpox disease raising hopes that red squirrels have now developed a natural immunity.