Sciurus vulgaris

Red Squirrel

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Description: Long body and tail, long back legs, shorter front legs with very dextrous paws.  Coat predominantly reddish in colour with white underside though colour variable from bright ginger through to red and dark brown or near black; bushy tail often used for balance and signalling which bleaches white by late summer in some individuals.   Ear tufts are noticeable especially in winter coat; grey squirrels lack these tufts.  Squirrels moult twice a year and coat colour and thickness can vary considerably with the season.

Size: Head and body about 180-240mm, tail about 175mm.

Weight:   Juveniles: 100-150g; Adults up to 350g.

Lifespan: Individuals of up to six years old have been known in the wild; lifespan likely to be even longer in captivity.

Breeding: Breeding can begin in mid-winter and continue through the summer, depending on the weather and how much food is available.  Mating chases occur where several males follow a female who is ready to mate.  During chases squirrels make spectacular leaps through the tree canopy and spiral up and down tree trunks.  Females have one or two litters a year, usually of about two to three young. Juveniles are weaned at around ten weeks, but do not breed until they are one year old.

Habitat:  Historically, probably similar to the UK habitat of the grey squirrel Sciurus carolinensis today; woodlands, parks and gardens.  Red squirrels spend about three-quarters of their active time above ground level, in trees and shrubs.  They are at home in both conifer forests and broadleaved woodland.

Diet: The main foods are tree seeds, especially hazel nuts and seeds from conifer cones.  Red squirrels will also eat tree flowers and shoots, mushrooms and fungi from under tree bark.  They often suffer periods of food shortage, especially during July.

General Ecology: Red Squirrels are active during the daytime, though in summer may rest for an hour or two around mid-day.  Squirrel nests, or dreys, are constructed of twigs in a tree fork above a whorl of branches close to the stem of a conifer or, less visibly, in a hole in a tree.  They are lined with soft hair, moss and dried grass. Several squirrels may share the same drey, or use the same drey on different days.

Distribution and main sites: The red squirrel is native to the UK but since introduction of the grey squirrel its numbers have decreased.  In the UK it is now only found very locally on Anglesey, certain parts of north and mid Wales, the Formby area of Lancashire, Norfolk, Cumbria, Northumberland and parts of Scotland, all locations where grey squirrel populations are low.  Where the species occur together, greys tend to be dominant.

Local Survey history: The species has not been credibly recorded in Shropshire for many years, possibly not since the 1960s.

Conservation Status: Red squirrels are protected by law, and may not be intentionally trapped, killed or kept, or have their dreys disturbed except under licence from Natural England (NE), the Countryside Council for Wales (CCW) or Scottish Natural Heritage (SNH).  Red squirrels are considered vulnerable in Britain.  However, occasionally high densities in some Scottish forests can lead to economic damage to trees. In such cases, government agencies will assess whether to issue a licence to remove some of them.  Despite historically high numbers, the introduction of grey squirrels during the early 20th century greatly contributed to their decline through disease transfer and indirect competition (better foraging efficiencies).  The only certain way to sustain red squirrel populations is through the exclusion of grey squirrels.  This can be achieved through the creation of habitats favourable for only red squirrels, selective feeders or lethal exclusion.  To improve the success of reintroductions further research is required

Threats: Competition from grey squirrels, squirrel pox (carried harmlessly by greys but fatal to reds) and also a form of leprosy are all threats to the survival and expansion of the red squirrel nationally.  The official ICTV (International Committee on Taxonomy of Viruses) acronym for Squirrelpox virus is SPPV.  The exact classification of the virus is still under debate.

Action: Volunteer groups have sprung up all over the UK all with a common objective – red squirrel conservation.  However, in order for red squirrels to gain a foothold, constant effort is required hence the formation of the Red Squirrels United (RSU) project.  The Wildlife Trust is the project lead along with seven other partners: Lancashire Wildlife Trust, Northumberland Wildlife Trust, Red Squirrels Trust Wales (RSTW), Ulster Wildlife, Wildlife Trust of South and West Wales with Forest Research and Newcastle University being Research Partners.

Main recording methods: In areas where animals are scarce, camera traps can confirm their occurrence.  In areas such as Anglesey, where red squirrels are comparatively common, they can be seen visiting bird feeders in suburban gardens as well as feeding sites in well-visited tourist areas such as Newborough Warren.

Field signs

Tracks: Squirrel leave tiny tracks in mud or snow, which can be easily overlooked.  See photo, above.

Forefoot width 25mm, length 35mm.

Hind foot width 35mm, length 45mm.

Feeding signs: The red squirrel eats nuts, acorns, berries and the cones of conifer trees (see photo).  They split acorns and hazelnuts and leave rough often jagged edges.  Pine cones are stripped, leaving the top sections untouched.

Nests: The nests of red squirrel (and grey squirrel) are known as dreys.  They are spherical collections (approx. 30cm across, at least 6m above the ground) of twigs and leaves which are usually located in the fork of the branches, close to the trunk.  It is easier to observe these in winter, when there are fewer leaves on the trees.  It is not possible to distinguish between red and grey squirrel dreys.

Droppings:

Droppings vary in shape according to diet, but can be round, resembling those of a rabbit but smaller; or cylindrical, resembling those of a rat but bigger.  Red squirrel droppings are a little smaller than those of the grey.

Skull

Skull smaller & cranium more rounded than grey squirrel

S. carolinensis

Length of nasal bones typically less than 16mm

Skull unlikely to exceed 54mm long; more typically 45 – 49mm

Skull width 27.5 – 31.5mm

Dental formula of both squirrel species:

incisors 1/1; canines 0/0; premolars 2/1; molars 3/3 x 2 = 22

(the first figure represents the number of teeth of each kind on the upper jaw, the latter figure the number on the lower mandible.

Skull photos of a specimen in the World Museum, Liverpool

Photos credit Ric Morris

Did you know?  All mammals have a ridge on the outer aspect of their scapula (shoulder-blade) for attachment of the muscles of the upper front limb. The inner aspect of the scapula, which lies against the ribs, is flat.  However red (and grey) squirrels have an extra ridge on the inner aspect of the shoulder-blade, and they’re the only UK mammals to have this feature.  Perhaps this allows attachment of extra musculature to increase the squirrels’ climbing agility?

Shropshire Lore: It is possible that among the most recent anecdotal sightings were made in the oak woods just off the A488 in the Hope Valley between Minsterley and Bishops Castle, circa mid/late 1960s (personal conversation with Colin Preston of Shropshire Wildlife Trust, who received reports from an unknown witness in south west Wales, who had grown up in Shropshire and attended the old Hope Junior School (now a private house).

Species page compiled and written up by Ric Morris, January 2020.

© Shropshire Mammal Group 2020