A tale of two squirrels

Martin Walters discusses greys and reds.

Some years ago, I was invited to a dinner party at a country farmhouse, where the conversation was dominated by discussions of horses, dogs, harvests and other rural matters.

Introducing a wildlife theme, I mentioned the often-amusing tactics of grey squirrels as they competed for food with our garden birds. Whereupon our elderly hostess turned to me and, mentioning her disgust for these alien ‘tree-rats’, asked me “why don’t you just shoot them?”.

Somewhat taken aback, I hesitated, then searching for a suitably diplomatic response, replied in a stumbling fashion “I don’t have a gun”. This exchange demonstrates a widely held view that grey squirrels are at worst a pest, and at best a nuisance.

Not so the gentle, beautiful, and now sadly rare red squirrel, an animal revered by all, not least through the inspiration of Beatrix Potter’s creation, Squirrel Nutkin.

Red squirrels, though common across much of Europe, where they are often dark brown, are now restricted to particular localities in the UK. Red squirrels have lived here for 10,000 years, whereas their grey cousins are newcomers, having been introduced from their native North America by the Victorians in the 1800s.

They were first recorded as having established a wild population in 1876, since when they have never looked back. Ecologically more versatile than reds, grey squirrels are common in most woods and forests and are frequent visitors to gardens.

They can certainly be a nuisance when they dig holes to bury nuts in the soil of potted plants and lawns, and many gardeners dislike them. But the real sadness is that they are the main reason for the red squirrel’s decline, along with loss and fragmentation of our native deciduous woods.

As well as out-competing reds, greys brought with them a nasty virus, squirrel pox, to which they have evolved immunity, but which is often lethal to reds.

As we humans know to our cost, novel viruses can quickly cause major problems, until natural immunity or vaccines can reduce their impact.

Just as red squirrels are often brown or almost black in some regions of Europe, so grey squirrels are sometimes black, notably in certain areas around Cambridge.

These melanistic greys are thought by some to have arisen from hybrids between grey squirrels and fox squirrels, another North American species that is sometimes black. They were first spotted in Letchworth in 1912.

[Read more: The wildlife and plants of County Cork in Ireland]

The UK population of red squirrels is now estimated at fewer than 160,000, mostly in Scotland, with pockets in Wales, and in the Isle of Wight and on Brownsea Island in Poole Harbour.

I tried in vain to see them on the Isle of Wight a few years ago but was successful during a recent visit to Brownsea, where there are said to be about 200. Dainty, and mostly elusive, they are much fussier about their diet than greys, preferring seeds from trees, including pine, and from other plants, as well as shoots, bulbs, wild fruits, and sometimes insects.

The nearest site to Cambridge for red squirrels is on Mersea Island off the Essex coast where small numbers persist following introduction in 2012.

The good news is that another of our native rare mammals, a predator of squirrels, may ironically be helping the red squirrel to recover.

Pine martens are expanding their range and where they encounter grey squirrels are turning the balance back to favour reds by preying mainly upon greys that are easier to catch as they spend more time on the ground and are perhaps less agile in the trees.

Though mainly silent, both grey and red squirrels make a range of sounds, including bird-like calls. Reds are generally quieter, whereas grey squirrels are noisy at times, especially in the mating season.

Grey squirrels recently constructed a drey in one of the trees in our garden, but before they could breed there, a pair of woodpigeons built their nest on the top, whereupon the squirrels deserted to build again in a tree in a nearby garden.

After the pigeons had reared their brood, the squirrels returned to start repairing the original drey, but I knocked the remnants out before they had finished the job. As mentioned earlier, I don’t have a gun!

I am grateful to local photographer Simon Stirrup (simonstirrup.co.uk) for his lovely photographs.

• Martin Walters is a Cambridge-based nature writer and conservationist.