Red squirrels have a very limited distribution in the UK due to native habitat losses and fragmentation as well as the introduction of the grey squirrel from North America in the 1870s. The situation has further deteriorated due to Squirrel Pox Virus, which was first detected in the 1980s. The virus is usually fatal to red but not gray squirrels. If a red squirrel population is decreased by Squirrel Pox Virus, they cannot usually recover due to being out-competed by gray squirrels. As a result, red squirrels are now one of the most threatened native UK mammals. Find out more about red squirrel conservation here.
Fortunately, recent studies show that current red squirrel range is being maintained, and red squirrels remain widely distributed across northern England. Red squirrels have several strongholds in the north of England, including Cumbria, North Yorkshire and Northumberland, in places such as Kielder, Harwood, Slaley and Kyloe. Northumberland National Park is another stronghold. Red squirrels are known to be present in Cragside, Allenheads, Greenhead, Swarland, around Ponteland, Morpeth and Ashington and along the Northumberland coast north to Alnwick.
However, gray squirrels are increasingly being detected in places such as Haydon Bridge, Corbridge, Hexham and the North Tyne area. Due to difficulties in controlling their populations, grays are quickly able to colonise new areas, or re-colonise areas from which they have been previously removed. Grays often use river corridors (such as the Irthing and the Liddle in Cumbria, and the Tyne in Northumberland), which goes some way to explaining their consistent prevalence in these areas. Sadly, red squirrels are no longer found in the parks of Newcastle and Sunderland.
There is, however, some good news: Where there are concerted efforts to control numbers of gray squirrels, it is possible to maintain red squirrel populations, for example, red squirrels were the only species detected in several surveys in parts of Northumberland, including around Rothbury, Kielder Forest, Kidland Forest, Redesdale and Wallington.