Squirreled away in the South
There’s a regional divide when it comes to the prevalence of squirrels
YOU’RE far more likely to find squirrels in the South of Britain than you are in the North - and it’s putting the health of woodland in the area at major risk. Data from Forest Research suggests squirrels are most common in the South West of England, and least common in Scotland.
The figures are based on the prevalence of bark stripping damage made to trees by squirrels when they gnaw at the stem to get to the sap.
Bark stripping can kill the trees outright, or damage them enough to allow infections in.
In the South West, 32% of the areas surveyed by Forest Research had evidence of squirrel damage, compared to just 0.3% of those in Scotland.
The figure stood at 11% of the areas surveyed in Wales, and 16% of those across England as a whole.
Within England, squirrels appear to be least common in the North West, with bark stripping observed in just 2% of areas surveyed by Forest Research.
The report notes that squirrel prevalence is particularly low in a strip running from the Mersey to the Wash, which they say could be related to low levels of woodland in the Liverpool and Manchester conurbation, Pennines and the Wash.
The report does not distinguish between red and grey squirrels, but experts say bark stripping is much more common among grey squirrels.
Red squirrels are native to the British Isles, while grey squirrels are an introduced species and were actively encouraged to establish in Britain between 1876 and 1929.
From that point in time grey squirrels have spread through parts of Britain, gradually displacing the native red squirrel in most of England and Wales, and in central and south-east Scotland.
Grey squirrels carry a squirrelpox virus that kills red squirrels, and outcompete them for territory and food - but they also pose a major threat to trees.
A new report by some of the largest forestry organisations in England and Wales estimates grey squirrels will cost the sector at least £1.1 billion over the next 40 years – in damaged timber, lost carbon revenue, and tree replacements.
Woodland owners have named the grey squirrel as the number one threat to their broadleaf woods, and land managers report a trend to avoid planting broadleaved tree species that are most vulnerable, including oak, beech and sycamore - which could impact woodland biodiversity in the future.
Royal Forestry Society Chief Executive, Simon Lloyd says: “Woodland creation is at the top of the forestry policy agenda, but many of those new trees will not survive to deliver the carbon capture or biodiversity objectives if grey squirrels cannot be controlled.
“If woodland owners are deterred from planting species such as oak within woodland mixes we may be looking at a loss of home-grown high-quality hardwood timber, further increasing a dependency on imports.”