WILDLIFE Grey squirrels are damaging the UK’s forests and could make the native red squirrels go extinct.
1 BOTH HAVE bushy tails and beady eyes, which makes them look rather cute. But while Britons love their native red squirrels, their grey American cousins are not so popular. The UK wants to reduce the grey squirrel population because they are replacing native red squirrels and damaging forests.
2 Grey squirrels are native to North America. They were first brought to the UK in the 19th century by Victorian landowners who kept them as pets. But they spread across the UK and are now the dominant species in most of Britain. While there are only around 140,000 red squirrels left in the UK, there are about 2.7 million grey squirrels there now. The Red Squirrel Survival Trust says that red squirrels could become extinct within the next ten years.
3 Grey squirrels can outcompete their British cousins when it comes to food. The two species do not directly fight over food, but the grey ones are better at getting the nuts, seeds and berries that they both eat – sometimes even in an unfair way: by eating red squirrels’ winter store.
4 Grey squirrels also carry diseases to red squirrels which weaken and kill them. A parasite that grey squirrels can transmit to red squirrels makes them less active so they forage less and don’t get enough food. That makes them smaller and less likely to breed. Even worse, the grey squirrels carry a virus, known as squirrel pox, to red squirrels. The grey squirrels are themselves immune to it, but it kills the reds.
5 Grey squirrels also damage trees, especially young ones, stripping off their bark and eating their seeds. Planting new forests has become almost impossible in many places. Because grey squirrels cause so much trouble for red squirrels and trees, people are looking for solutions.
6 One idea is to move red squirrels to protected islands and just let grey squirrels take over the British mainland. But red squirrels are so popular that not many people would support such a plan.
7 A more natural solution to the grey squirrel problem would be pine martens. They were almost hunted to extinction, but they are making a comeback. And where there are pine martens, grey squirrel numbers go down. Pine martens prey on grey squirrels more than they do on red ones. But pine martens avoid cities, where grey squirrels thrive. Because it is unlikely that pine martens will spread all over Britain, and because they are also dangerous for other wild animals and domestic animals like chickens, they won’t be the only solution.
8 Another idea is oral contraceptives. They can be put in feeders that only grey squirrels can get to. The contraceptives can be hidden in hazelnut spread. Putting them in hazelnut spread and not in nuts makes sure that no other animals find them buried somewhere and eat them. Research has shown that around 90% of squirrels in an area can be treated using this method. Seen as more humane than other methods, the UK government supports the plan, so it could soon be used.
9 However, there are still some ethical concerns because scientists do not know what physical and psychological effects an inability to breed will have on the grey squirrels. Nor do they know what effects it will have on predators that eat squirrels treated with contraceptives.
10 Although they are not well-loved, Jason Gilchrist, an ecologist at Edinburgh Napier University, points out that, “Greys did not come over here of their own accord and did not ask to be introduced. Neither do they have any control over the pox they carry”.
11 Hopefully, a mix of different humane solutions will reduce grey squirrel numbers in the UK so that red squirrels and forests there can recover.