Americans Are Invading the UK


A battle is raging in Britain between the natives and the Americans. In this case, the fighting concerns two species of squirrel: the red and the grey, and it doesn’t look favorable for the reds. The red squirrel
is Britain’s only native squirrel species but its future is increasingly uncertain, and the North American grey squirrel could be to blame.

In the last half of the 19th century, unwitting Victorians had returned home from their travels to America with the unique grey squirrels, and had released them in a park in Cheshire. Within 25 years, the American squirrels had colonized an area of approximately 300 miles in England and Scotland. Fast forward nearly 150 years later and the bushy tailed Americans’ propensity to expand their range and procreate has resulted in an estimated population of 2.5 million grey squirrels in Britain, compared to only 140,000 red squirrels.

One reason to account for the imbalance is that greys are more prolific breeders with two litters a year compared to the reds, who only have one litter per year. A decline in red squirrel populations is thought to be due to competition for food and the result of disease. Grey squirrels consume seven times more food and they can eat food before it is ripe enough for red squirrels. Most notably, grey squirrels are carriers of the squirrel pox virus, which does little to harm them since they have developed an immunity to the disease but exposure for red squirrels is deadly.

Compared to the beloved British squirrel that was popularized by the writings of Beatrix Potter, the larger and more aggressive American squirrel is sometimes considered an intruder. In Britain, there is much debate on if and how the populations should be controlled to protect the red squirrel’s existence.