It is true that grey squirrels are not native to this country (in the sense in which it is appropriate to talk of “native” on territory that was scraped clean by ice 10 000 years ago). They were introduced from American in the 19th century, at a time when it was fashionable to move animals between continents. Now there are between 2 and 3 million greys and between 150 and 200 thousand reds, which represents a substantial difference. So, on the face of it, it seems to be an open and shut case: the greys replaced the reds.
The reality, however, is not as straightforward as that. To properly unravel the accusation, we have to consider the actual history of red squirrels in Great Britain.
First and foremost, it is important to note that red squirrels are not a rare or endangered species, their conservation status is “least concern”. They are abundant in the rest of the world, wherever the habitat – extensive pine forests or an equivalent in wildlife corridors – is available to them. In Great Britain, however, habitat loss (deforestation, as a result of human activity) drove them to the point of extinction in the 18th century. The specifically British sub-species of the red squirrel, siurus vulgaris leucurus, is, unfortunately, extinct. This happened before grey squirrels were introduced! So the idea that once we had a lot of red squirrels, and then greys were brought in and fought them, and killed them, and drove them out, is undeniably false. And yet this is the image that somehow has lodged itself in popular imagination. Urban mythology at its confused best.
But back to the story of the reds, because it gets even more interesting. Red squirrels were then themselves reintroduced from continental Europe, so that red squirrels living in this country today are not, properly speaking, native to this country, but to Scandinavia. By a stroke of good fortune, the numbers of red squirrels recovered when hazel coppicing was a widespread economic practice, they managed to adapt to that as a new habitat. In fact, the recovery of the reds coincided with the introduction and spread of the greys in the 19th and early 20th century. At that time red squirrels did so well that they were considered the “pest” and persecuted and hunted in exactly the way the greys are today – hunting clubs were set in an attempt to kill off the reds. Curiously, they were accused of the same crimes that grey squirrels are accused of today, namely, damage to forestry and eating birds. The “iconic British mammal” of today’s newspaper articles was not always that. It was “vermin” and “pest” only a few decades ago.
When hazel coppicing as an economic practice stopped, red squirrels ran out of luck. Their numbers crashed again – a process that was sped up massively by disease outbreak. (Before you ask, nothing to do with “squirrel pox” caught from grey squirrels). Beyond that point in British history, the reds could not adapt to other habitats. The greys, by contrast, adapted, and continue to adapt.
So the present difference in the numbers of reds and greys is easily accounted for by habitat factors, by the fact that red squirrels need a very specific habitat – extensive pine forests (or at least hazel groves or mixed forests), whereas the greys can adapt to almost any environment: pine forests, deciduous forests, and even our parks and gardens.
There are projects in this country claiming to prove that, if only grey squirrels did not make life difficult for their red cousins, the reds would come back and thrive. Using public grants, these projects undertake extensive and cruel killing of grey squirrels and then put out press releases announcing that red squirrels are indeed coming back. However, if we look closer at what is actually happening there, we find that the red squirrels are artificially maintained – with captive breeding programmes, feeding stations, nest boxes, like a large zoo. It is hardly moral to kill off one species that fits the habitat well and artificially maintain another, that you prefer for sentimental reasons, even though it cannot survive in this habitat unaided.
However, in areas where the habitat is still right for red squirrels, they do coexist with the greys, they have even been known to share the dreys.
Another factor that is often mentioned in this connection the pox virus. It kill red squirrels (thought they are slowly developing immunity to it), whereas the more robust greys carry the virus without becoming ill themselves. This fact leads to the accusation that the greys are killing the reds with the pox virus. This accusation, however, does not take into account the actual process of disease transmission. In practice the vast majority of the reds do not get the pox from the greys, but from fellow reds. In most areas where a similar or the same disease first broke out at the beginning of the 20th century there were no grey squirrels at all. In fact, grey squirrels are only indirectly to blame for the pox, whereas the artificial maintenance of red squirrel colonies in England can be blamed directly: feeding stations cause a high concentration of animals in one place, which provides ideal conditions for the virus to spread. So next time a newspaper or social media news item tries to get your support for killing grey squirrels by showing you a picture of a red squirrel dying from the pox, remember that the poor creature is far more likely to have got the virus from a fellow red via a shared feeder, rather than from a grey squirrel. In reality, red squirrels die from a variety of causes, most of them to do with humans, such as traffic, and from a variety of diseases, of which the squirrel pox is only one.