Red Squirrels vs. Grey Squirrels: The Story Behind Britain’s Woodland Rivalry

For many people, the squirrel in storybooks and the squirrel in the local park are two very different animals. The squirrel of old illustrations, including Beatrix Potter’s Squirrel Nutkin, is small, russet, and tufted-eared. The squirrel most people in Britain actually see today is larger and grey. The story of how one replaced the other across much of the country is one of the clearest examples of what a single introduced species can do to a native one.

Meet the Two Squirrels

The Eurasian red squirrel (Sciurus vulgaris) is native to Britain and much of Europe and northern Asia. It is smaller and lighter than its grey cousin, with a coat that ranges from bright ginger to dark brown, and in autumn and winter it grows the long ear tufts that make it so recognizable. Reds are especially at home in conifer forests, where they strip pine and spruce cones for their seeds.

The eastern grey squirrel (Sciurus carolinensis) is native to the deciduous forests of eastern North America. It is heavier, more robust, and has no ear tufts, although greys can show brownish tints on their backs and flanks in summer, which sometimes leads to confusion.

How the Greys Arrived

Grey squirrels did not cross the Atlantic by accident. In the late 19th and early 20th centuries, they were deliberately released on country estates across England as a fashionable novelty; one frequently cited early release took place at Henbury Park in Cheshire in 1876. Nobody at the time anticipated the consequences. Greys adapted quickly, spread across the countryside, and today number in the millions, while red squirrels have retreated to a much smaller range, with Scotland holding the majority of Britain’s remaining population, along with strongholds such as Anglesey, the Isle of Wight, Brownsea Island, and parts of northern England.

Why Reds Lose Out

Greys do not usually fight reds directly. Their advantage is quieter and more effective, and it comes down to two main factors.

Food competition. Grey squirrels can digest acorns while they are still green and high in tannins, which red squirrels cope with poorly. In mixed broadleaf woods, greys can therefore strip a food supply before the reds can use it, and greys also raid the reds’ buried stores.
Disease. Many grey squirrels carry squirrelpox virus without apparent harm. In red squirrels, the same virus is usually fatal, and where the two species overlap, outbreaks can wipe out local red populations remarkably quickly.

Habitat loss and fragmentation have made things harder still, because isolated pockets of reds have nowhere to retreat to when greys move in.

Forgetful Gardeners of the Forest

Whatever their color, squirrels play a real role in how forests grow. Both species cache food for leaner months, burying nuts and seeds one at a time in scattered spots, a strategy known as scatter-hoarding. They rely on memory and smell to find them again, but not every cache is recovered, and the forgotten ones can germinate. Over many years, squirrels effectively plant trees, particularly oaks, hazels, and beeches, often far from the parent tree.

An Unexpected Ally: The Pine Marten

One of the most hopeful developments in red squirrel conservation involves another native animal. Research in Ireland and Scotland has found that where pine martens, a native woodland predator, have recovered, grey squirrel numbers tend to fall while red squirrels hold on or return. One explanation is that reds evolved alongside pine martens and are lighter and more cautious, while heavier greys, which spend more time on the ground, are easier prey. It is not a simple fix, but it suggests that restoring whole woodland ecosystems may help the red squirrel more than any single measure.

How You Can Help

Report sightings of red squirrels, and of greys in red squirrel areas, to local conservation groups, which use this data to track the frontier between the two.
Clean garden feeders regularly in areas where both species live, because shared feeding points can spread squirrelpox.
Support woodland conservation and native tree planting, particularly conifer and mixed woods that suit reds.
Visit a stronghold. Places such as Brownsea Island or the Scottish Highlands offer a real chance of seeing reds in the wild.

For more on the forest’s year, see how forests change through the seasons, or meet the fox, the hedgehog, and the otter.

Our little red squirrel is one of the characters we paint most often, and you can find it in our watercolor prints in our Etsy shop, NaturalEMNB.