The continuing success of its woodland rival, the introduced grey squirrel, is driving the native red from more and more of its remaining habitats in England, Wales, Scotland and Northern Ireland, the report says.
Apart from populations on the Isle of Wight and on Brownsea Island in Dorset, and a few individuals in Thetford Forest, Norfolk, the native red has virtually gone from England south of Lancashire.
Although there are still good numbers in Northumberland, Durham and Cumbria, these too are at risk. Northumberland was invaded by greys five years ago, and the report's assessment is that the estimated 30,000 red squirrels remaining could be lost from mainland England by 2010.
The red squirrel, Sciurus vulgaris, is no ecological match for its North American cousin the grey, Sciurus carolinensis. However, the report debunks the common belief that greys attack reds and drive them away. They simply eat them out of house and home. Greys also carry a virus called parapox to which they are resistant but which the reds find fatal.
Grey squirrels were first introduced to Woburn Abbey in Bedfordshire in 1867. They have increased to more than 2.5 million. Their colonisation continues at the rate of about six miles a year.Reuse content