The red squirrel is Britain’s only native squirrel; they were once the only squirrel species in Britain and were widely distributed.
The red squirrel is much smaller than the grey squirrel, with a body up to 25 cm long, and a tail of up to 20 cm, weighing around 300 grams.
Despite its name, the red squirrel’s coat varies in colour from a fine russet or chestnut colour in summer to dark brown or even greyish in winter, although there is a great deal of variation in individual coat colours.
Bleaching can occur of the ear tufts and tail. A distinctive feature of red squirrels is a white belly and pointed ear tufts; in winter, the ear tufts are especially prominent.
In Wales, ‘pocket’ populations of red squirrels can be found in Anglesey, mid Wales and, Clocaenog Forest in north eastern Wales.
Red squirrels are shy, solitary and secretive creatures, with peaks of foraging activity in the early morning and late afternoon.
They spend about 80% of their time high in the canopy, and are therefore rarely seen.
Red squirrels build nests, called dreys, built high in the branches from sticks and moss. They produce up to two litters of three to four kittens a year, usually in March and July.
Red squirrels feed high in the canopy on nuts, kernels from pine cones, fungi, berries and fruit, flowers, buds and even insects.
Unlike grey squirrels, red squirrels cannot easily digest seeds with high tannin content, such as acorns, which limits the available food sources. Favoured coniferous species are Scots pine, Japanese Larch, Lodgepole Pine.
Once common, red squirrels have declined rapidly since the 1950s. Numbers in the UK have fallen from around 3.5 million, to a current estimated population of around 120,000, of which 75% or more are in Scotland; strongholds exist in areas which have not yet been colonised by grey squirrels.
In Wales, ‘pocket’ populations of red squirrels can be found in Anglesey, mid Wales and north eastern Wales, in the Clocaenog Forest.
The largest factor affecting the survival of the native red squirrel is the presence of the grey squirrel. This larger species competes for resources with the native red squirrel and carries the Squirrelpox virus (parapox), which is deadly to the red squirrel but to which the grey is immune.
In Britain, the grey squirrel is an invasive non-native species.
The International Union for the Conservation of Nature (IUCN) includes grey squirrels in a list of 100 most invasive species in the world
Grey squirrels were first introduced in 1876 at various locations throughout Britain; they were regarded by the Victorians as an ornamental species.
The grey is much larger then the red squirrel and has a more robust build, with a body of around 30cm in length and a tail of 25cm.
The grey squirrel weighs in at between 540 and 660 grams, although some individuals of up to 840 grams have been identified in mid Wales.
The grey’s fur is mainly grey with mid-brown along the upper back and chestnut over the flanks, limbs and feet. Their underside is white.
The tail hairs are grey, banded with brown and black and a characteristic white fringe, creating a ‘halo’ effect which can be a useful distinguishing characteristic.
They have pale ears with no ear tufts.
Grey squirrels share food sources with reds. However, unlike red squirrels; greys can feed on seeds with high tannin content, such as acorns.
As a result, more food sources are available to grey squirrels and they tend to put on 20% in body weight over the autumn, compared with 10% for reds. This gives grey squirrels an advantage in hard winters.
Estimates vary, but there is thought to be over 3 million grey squirrels in Britain.
Grey squirrels prefer oak, beech, sweet-chestnut and horse-chestnut habitats.
Grey squirrels can also make use of coniferous habitats (mainly Scots pine and Norway spruce) especially if there is good broadleaved habitat within 1 mile.