The grey squirrel has become rural enemy number one in recent years for good reason. Its relentless bark-stripping and nest raiding have put it firmly on the list of a “shoot-on-sight” species. Foresters, farmers and country folk have all evidenced its danger to tree cultivation and to resident songbird species. On shooting estates, predation of game-bird nests makes it intolerable. In some areas, local culls have been authorised (particularly to protect breeding sanctuaries for red squirrels) and the call for a national pogrom comes as no surprise.
So what about this estimated £10 million worth of damage to forestry annually? Grey squirrels attack the primary shoots of newly sprouted trees on plantations, which are rich in protein. Even when they don’t kill the sapling, it will grow misshapen and become a commercially worthless timber. The most serios crime, however, is indiscriminate ‘barking’ of trees. This involves stripping significant sections of bark from mature trees, usually over ten years old. Not to eat the bark itself but to extract nutrients and water from the exposed softer cambial wood beneath. Barking is usually done in late spring or early summer and where ring-barking (removing the bark from right around the trunk) occurs, the wood above the ring will die. The leaves are unable to photosynthesise as they have no water, so no food travels back down the trunk to sustain its life. Open wounds on a deciduous tree from bark removal can heal, but many are attacked by fungi, weakening the timber and leaving it susceptible to storm damage.
Never under-estimate the grey squirrels penchant for fresh songbird, game-bird and pigeon eggs or young chicks. Squirrels are omnivorous and are highly adept, curious, athletic climbers and jumpers. They will reach any food they set their sights on, we’ve all seen the ‘Mission Impossible’ type documentaries. The nickname ‘tree-rat’ is used often and, in my opinion, justified. Like the brown rat, they have little fear when feeding. On the ground they will boldly evict a bird as large as a pheasant and they will strip a pheasant or partridge nest of eggs within ten minutes. Greys will even tackle the nests of aggressive birds like the jay, hence they are mortal enemies. They are also a visible nuisance around bird tables, cleverly raiding feeders and seed left out for songbirds, bullying the birds away.
The grey rarely physically attacks the red squirrel, though this has been documented. Although both greys and reds have a bi-annual breeding cycle, similar sized litters and compete for the same food and territory … it was inevitable that the larger, more aggressive grey squirrel would push the red squirrel close to extinction in this country. One of the main reasons, however, has been because the grey squirrel is a vector for the squirrel parapox virus (SQPV, see separate chapter) to which it is largely immune but which is lethal to the more fragile red squirrel.
In many urban areas and parks, the grey squirrel is adored by the public. Perhaps understandably as it is a wild creature freely available for viewing by the public and in many cases, the only wild animal many children will get to see. Yet parkland and public spaces house few, if any, of the grey squirrels natural predators so they thrive unchecked. They lose their timidity and are so approachable that many can be hand-fed (so not wild in my eyes!). It will be interesting to see how Her Majesty’s Government and Local Authorities approach a request to cull these parkland animals and … if they do … how they tackle the job under the gaze of a distressed and protesting public? Of course, if they don’t get culled too, these enclaves will be the breeding ground for the re-emergence of the grey squirrel in rural areas.
Copyright Ian Barnett, Wildscribbler, Dec 2015