There are no two ways about it, grey squirrels are bad for the British countryside
This article by , Honorary Visiting Research Fellow, was originally published on . Read the .
According to some animal rights groups the grey squirrel is a . They say it has been made a for regional red squirrel population extinctions and claim that loss of the reds is caused entirely . They suggest the and scientific research being .
The grey squirrel- victim of circumstance?If so, then this conspiracy must extend to and both listing the grey squirrel as an invader to be controlled, right?
Well, no – put this argument to the test and you’ll see that the facts actually do stack up against the grey squirrel. The reality is that, while the grey squirrel is an important part of , since being brought to Europe by the in 1876, the animal has had severe on British woodlands.
Acrobatic and entertaining they may be, but the charge sheet against the grey squirrel is based on hundreds of peer-reviewed research papers. There really is no for it.
Greys vs red in Europe
Red and grey meet on the battleground.: David Bailey- author providedToday there are grey squirrels in Britain, but less than . Grey squirrels native reds for food and space. They also dig up and that red squirrels have buried as a winter store. This behaviour reduces red squirrel skeletal growth rates and adult size, and greatly depresses too.
In addition, greys harbour infections – including , which can devastate red squirrel populations. They , and bring in new parasites, such as , which are picked up by red squirrels.
Occasionally a healthy red squirrel is found with squirrel pox antibodies – some researchers have suggested that this is evidence of them to the pox. Unfortunately, 63% of red squirrels dying from pox have also been found to have this and there is no evidence that these antibodies confer immunity. Even if they did, research has also shown that antibodies are and, irrespective of any resistance, red populations would be replaced by grey via competition anyway.
Woodland damage
Grey squirrels also making it impossible for foresters to grow high-grade hardwood. This means such material is imported instead, bringing with it the risk of .
Tree damage is most frequently seen on the branches and trunks of oak, beech and maple; by squirrels eager to consume the . Tree stems break or die following stripping, which in turn leads to changes in the of high canopy in amenity woodlands.
Even songbirds are affected by grey squirrels. A of negative association between woodland songbird fledging rates and presence of grey squirrels – though it must be noted that this was not observed annually and only seen on some of the sites studied. Earlier studies didn’t find evidence to indicate greys , but also didn’t exclude the possibility – even for bird species whose population is increasing overall.
Other animals may be affected by greys too: there has been some suggestion that squirrels compete with , though more research is needed to .
Controlling greys
The Wildlife Trust has recently 5,000 volunteers to monitor and control grey squirrel populations. However, a look beyond the headlines will reveal thousands of people are already legally greys across the country to control their numbers. cull 6,000 grey squirrels per year in the north of England, for example. Even in areas where reds are absent, locals control grey squirrels to protect woodlands or . This is not some dramatic new approach by the Wildlife Trust, but is simply reinforcing an established national movement.
The eradication of greys from the saw red squirrel numbers increase from 40 to 700 and there are other of grey control halting or reversing red squirrel decline. Research has also demonstrated that red squirrels do not prefer habitat and are just as happy in either.
Future control may involve giving the squirrels , but will almost certainly not rely solely on this because of logistical barriers. The pine marten may assist in some landscapes too: found a strong negative correlation between pine martens and greys in the woodlands studied. However, the use of trapping and shooting will inevitably continue as part of an .
And so the grey squirrel stands guilty as charged. Their presence has decimated the British countryside since they were introduced from North America, and if we do not continue to control the species, the future for red squirrels and woodland ecosystems will be bleak.
Publication date: 6 April 2017