Red squirrel

Lore & Background

The red squirrel is found in coniferous and temperate broadleaf woodlands, with densest populations in large coniferous forests. It occupies boreal woods in northern Europe and Siberia, preferring Scots pine, Norway spruce, and Siberian pine. In western and southern Europe, it inhabits broad-leaved woods. The species is diurnal, active from sunrise, and spends 60% to 80% of its active period foraging. It does not hibernate but may remain in its nest during severe winter weather. Movement on the ground involves leaps and alert postures; in trees, it is rapid and agile, leaping up to four meters between trees.

Reader's Guide

The red squirrel is a widespread Eurasian rodent with over 40 described subspecies, though only 23 are currently recognized. Its taxonomic history includes several subspecies elevated to species status, such as the Calabrian black squirrel (S. v. meridionalis) in 2017 and the Japanese squirrel (Sciurus lis), which was historically classified as a subspecies. The species shows remarkable coat color polymorphism, ranging from red to black, with melanism common in continental and boreal populations. In Great Britain, Ireland, and Italy, red squirrel populations have declined due to the introduction of the eastern grey squirrel from North America, though conservation efforts in Scotland have stabilized the population. The red squirrel's long tail aids balance and steering during arboreal movement and may provide warmth during sleep.

Did You Know?

• The red squirrel sheds its coat twice a year, switching from a thinner summer coat to a thicker, darker winter coat with larger ear-tufts.
• There are 23 recognized subspecies of the red squirrel, though over 40 have been described.
• The Japanese squirrel (Sciurus lis) was historically classified as a subspecies of the red squirrel but is now considered a distinct species.
• Red squirrels do not hibernate but may stay in their nest for several days during severe winter weather.

A Name with Ancient Roots

The English word for this creature carries a remarkably long linguistic pedigree. First recorded in 1327, it passed through Anglo-Norman 'esquirel' and Old French 'escureil' before settling into its modern form, all descending from the Latin 'sciurus.' That Latin term was itself borrowed from the Ancient Greek 'skiouros,' a compound of 'skia' meaning shade and 'oura' meaning tail—a fitting description for an animal so defined by its bushy appendage. The genus Sciurus preserves the same root. Before the French borrowing took hold, Old English speakers used 'acweorna,' a word of Common Germanic origin that lingered into Middle English as 'aquerne' before being displaced entirely. Germanic cousins of that older term survive across the continent today: German 'Eichhörnchen,' Norwegian 'ikorn' or 'ekorn,' Dutch 'eekhoorn,' Swedish 'ekorre,' and Danish 'egern.' A gathering of these animals is poetically termed a 'dray' or a 'scurry.'

Built for the Canopy

Members of the squirrel family span an astonishing physical range, from the African pygmy squirrel measuring a mere 10 to 14 centimeters and weighing as little as 12 grams, to the Bhutan giant flying squirrel stretching to 1.27 meters, and marmot species topping 8 kilograms. Most share a slender frame, large forward-facing eyes, and a long, bushy tail. The hind limbs are generally longer than the forelimbs, and each foot carries four or five toes with soft pads and sturdy, versatile claws designed for gripping. Perhaps the most remarkable adaptation is the tree squirrel's ability to descend a trunk headfirst, accomplished by rotating the ankles a full 180 degrees so the hind feet grip bark in the opposite direction. The tail is a multitool: it shields against rain and cold, dissipates heat by increasing blood flow, acts as a counterbalance during leaps, functions as a parachute in mid-air, and serves as a visual signaling device. When the animal sits upright with its tail draped over the back, the silhouette can mask its shape from predators approaching from behind.

Rhythms of Life and Survival

Squirrels inhabit nearly every terrestrial environment on the planet, from dense tropical rainforests to semiarid deserts, shunning only polar extremes and the most arid wastes. They are predominantly herbivorous, relying on seeds and nuts, though many opportunistically add insects or small vertebrates to their diet. Breeding occurs once or twice per year, with a gestation of three to six weeks yielding altricial young—born naked, toothless, and blind. In most species the mother alone raises the litter, weaning the kits at six to ten weeks; sexual maturity typically arrives by the end of the first year. Ground-dwelling species gravitate toward social colonies, while their tree-dwelling counterparts tend to be solitary. Activity patterns vary by group: ground and tree squirrels are usually active during daylight or twilight, whereas flying squirrels are nocturnal, except lactating mothers and their kits, who shift to daytime activity through the summer. During extreme heat, squirrels have been observed 'splooting,' pressing their bellies flat against cool surfaces to shed body temperature.

Fragility, Caching, and Cleverness

Wild squirrel life is marked by vulnerability. A large proportion of juveniles die within their first year, and adult lifespans in the wild generally span five to ten years, though captivity can stretch survival to twenty. One particularly cruel hazard is a nest tumbling from its tree; if the mother senses her young's body temperature has fallen, she may abandon them. Professional wildlife rehabilitators can rescue and foster such premature infants until they are robust enough for release, yet the sheer density of squirrel populations and the intensive, continuous care these babies demand means few rehabilitators are willing to take them on, and many are euthanized instead. To buffer against food scarcity, squirrels employ species-specific caching strategies. In temperate zones, nuts are buried beneath leaf litter, tucked into hollow trees, or buried underground. In subtropical and humid regions, where traditional caching invites mold, decomposition, or premature germination, some species hang nuts and mushrooms on branches to keep them dry. Two flying squirrel species go further, carving grooves into nuts to wedge them between intersecting twigs in a technique that closely resembles a carpenter's mortise-and-tenon joint.