The Eurasian Red Squirrel is a species of tree squirrel. It is a tree-dwelling omnivorous rodent, common throughout Eurasia.
The coat of the Red Squirrel varies in colour with time of year and location. There are several different coat colours, much like hair colour in some human populations. The underside of the Red Squirrel is always white-cream in colour. The Red Squirrel sheds its coat twice a year, switching from a thinner summer coat to a thicker, darker winter coat. A lighter, redder overall coat colour, along with the larger ear-tufts and much smaller size, distinguish the Eurasian Red Squirrel from the American Eastern Grey Squirrel. The Red Squirrel has a typical head-and-body length of 19 to 23 cm. It is thought that the long tail helps the squirrel to balance and steer when jumping from tree to tree and running along branches and may keep the animal warm during sleep. The Red Squirrel, like most tree squirrels, has sharp, curved claws to enable it to climb and descend broad tree trunks, thin branches and even house walls. Its strong hind legs enable it to leap gaps between trees. The Red Squirrel also has the ability to swim.
During mating, which normally occurs in late winter during February and March, males detect females by an odor that they produce and although there is no courtship, the male will chase the female for up to an hour prior to mating. Usually multiple males will chase a single female until the dominant male, usually the largest in the group, mates with the female. Males and females will mate multiple times with many partners. Gestation is about 38 days. A female will normally produce her first litter in her second year. Up to two litters a year are possible and up to six young may be born. They are born blind and deaf and these do not start to function until about three weeks. The young suckle from the mother until about eight weeks.
The lifespan of the Red Squirrel is, on average, 3 years, although individuals may reach 7 years of age, and 10 in captivity. The survival rate of young squirrels is quite low. Arboreal predators include small mammals including the pine marten, wild cats, and the stoat, which preys on nestlings; birds, including owls, hawks and buzzards, may also take the red squirrel. The red fox, cats and dogs can prey upon the Red Squirrel when it is on the ground. Many become road casualties and others are controlled by hunting.
The Red Squirrel is found in both coniferous forest and temperate broadleaf woodlands. The squirrel makes a drey (nest) out of twigs in a branch-fork, forming a domed structure about 25 to 30cm in diameter. This is lined with moss, leaves, grass and bark. Tree hollows and woodpecker holes are also used. The Red Squirrel is a solitary animal and is shy and reluctant to share food with others. However, outside the breeding season and particularly in winter, several Red Squirrels may share a drey to keep warm. Although males are not necessarily dominant to females, the dominant animals tend to be larger and older than subordinate animals, and dominant males tend to have larger home ranges than subordinate males or females.
The Red Squirrel mainly eats the seeds of trees, neatly stripping conifer cones to get at the seeds within. Fungi, birds’ eggs, berries and young shoots are also eaten. Often the bark of trees is removed to allow access to sap. Excess food is put into caches, either buried or in nooks or holes in trees, and eaten when food is scarce.
The active period for the Red Squirrel is in the morning and in the late afternoon and evening. It often rests in its nest in the middle of the day, avoiding the heat and the high visibility to birds of prey that are dangers during these hours. During the winter, this mid-day rest is often much briefer, or absent entirely, although harsh weather may cause the animal to stay in its nest for days at a time.
The Red Squirrel is protected in most of Europe, but in some areas it is abundant and is hunted for its fur. Although not thought to be under any threat worldwide, the numbers of Red Squirrel has drastically reduced. This population decrease is often ascribed to the introduction of the Eastern Grey Squirrel from America. The Eastern Grey Squirrel population appears to be able to out-compete the Red Squirrel for various reasons:
• The Eastern Grey Squirrel can easily digest acorns, while the Red Squirrel cannot.
• The Eastern Grey Squirrel carries a disease, the squirrel parapoxvirus that does not appear to affect their health, but will often kill the Red Squirrel. It was revealed in 2008 that the numbers of Red Squirrels have recently declined by 80% as a result of this disease.
• When the Red Squirrel is put under pressure, it will not breed as often.
It is worth noting that the eastern grey squirrel and the Red Squirrel are not directly antagonistic towards each other, and direct violent conflict between these species is not a factor in the decline in Red Squirrel populations.
The Red Squirrel used to be widely hunted for its pelt. In Finland squirrel pelts were used as currency in ancient times, before the introduction of coinage. The expression “squirrel pelt” is still widely understood in Finland to be a reference to money.