The Grey Squirrel

Habitat

The drey (nest) may be in a hole in a tree or set against the trunk and branches. Alternatively they can make themselves quite at home in an attic or roof space.

Reproduction

Pregnancy (gestation) lasts 44 days, and their young are called kittens. They usually have two litters a year, each with three to seven kittens.

Young

Kittens are born with closed eyes, no teeth and no hair. After about seven weeks they look like small versions of their parents and are ready to leave the drey.

Coats

Squirrels moult their coat twice a year – once after Winter and then in the late Summer before the weather gets colder again.

Why control grey squirrels?

The grey squirrel was introduced to England, Wales, Scotland and Northern Ireland from North America in the Victorian era. It has since colonised 90% of England and Wales and has established a bridgehead in Scotland. In Britain, the grey squirrel has no natural predator. It is omnivorous, breeds strongly and is an aggressive settler- equally at home in urban parks and the countryside.

The grey squirrel, here in Britain and Europe, is classed as an Invasive Alien Species (IAS) and as such is recognised as being in the top worst 100 such species in the world. An IAS is any animal that is not native to the UK.

We can all appreciate the joy that squirrels bring the UK fauna enthusiasts. Red squirrels are not only protected but are much sought out because catching sight of them is so rare. Unless you’re around Scotland, Northern Ireland or the Isle of Wight, there’s a good chance you’ve never seen a red squirrel.

Squirrel distribution maps 1945-2000-2010 (image: Red Squirrel Survival Trust)

Even though the grey squirrel is still appreciated for its grace and ‘cuteness’ by much of the UK – the pest control industry knows that there are times when lethal control is necessary if the grey squirrel is causing a detrimental effect to human health or flora.

Grey squirrels not only damage our trees, gardens and houses, but they are also the principle threat to the survival of the native red squirrel in Britain.

Grey squirrels and our forests

Grey squirrels cause irreparable damage to trees such as beech, oak and chestnut. They strip bark at the base of trees which causes them to weaken or die.

Grey squirrels also raid birds’ nests to prey on eggs and fledglings, damage orchards and gardens as well as historic and ancient woodlands.

The European Squirrel Initiative (ESI) point out that around 12% of England is covered by trees and this is set to rise. Government grants assist with broadleaf planting, however as long as the grey squirrel is present we will never see trees in the future like we see them today. Newly planted trees will be damaged, and their growth will be impeded by grey squirrels. Woodlands become more important as we have more leisure time and bigger forested areas are more accessible. Woods and forests provide for carbon sequestration and help fight global warming. Timber also has an economic value and commercial forestry plays an important part in our rural economy.

Grey squirrels are not the only pest damaging our forest, in recent years we have seen a number of airborne diseases, possibly caused by climate change, devastating our native species. Ash Dieback and Acute Oak Decline for example. But grey squirrels affect all broadleaved trees and they are something that we can do something about. 

We plant around 40 million broadleaf trees a year and grey squirrels are the main pest where this new planting is being done. Impact is estimated to be between £15-£25 million per year in loss of timber, plus the loss in tax payers grant aid. Since the Great Storm in 1987, losses have been put at around £600 million.

ESI are concerned unless something is done, there will be no oak, beech, or sweet chestnut mature trees for the next generation.

Squirrels in and around your home

Grey squirrels can cause damage when they enter roof spaces of houses and buildings. For example, they can:

• Chew on woodwork and ceilings
• Strip insulation from electrical wires
• Tear up fibreglass insulation 
• Contaminate cold water tanks with urine and droppings.

Clients also report sleep pattern issues due to noise and even fear of being attacked (although being attacked by a squirrel is very rare). 

In gardens and allotments, they can take fruit, raid nests of small birds and dig holes in lawns to bury food.

[Did you know?]

• The male squirrel is called a buck and the female a doe.
• Squirrels can be right or left-handed!
• Squirrels were deliberately introduced from the USA and Canada to approximately 30 sites in England, Scotland and Wales from 1876 to 1930. 
• Squirrels can hang upside down like bats and are pretty good swimmers.

How to keep Squirrels away

Firstly, habitat management such as cutting back trees or branches that are overhanging a building, or trimming dense ivy can also help prevent squirrels gaining access to a roof in the first place.

Proofing entry points to roofs should be considered next. For example, block gaps and entrance holes with tightly wedged mesh or metal plates, where possible.

For tree protection, close fitting metal sleeves can protect them from the strong rodent incisors. This should be at least 0.75m deep, and the bottom edge should be at least 1.5m from the ground.

The metal should be a smooth surface to assist in preventing the squirrel from gaining a toehold.

How to get rid of squirrels

It’s important with squirrels (as with all pest species) that the pest controller assesses whether lethal control is necessary. While some see them as vermin others may see them as a welcome natural occurrence, and pest controllers could see themselves in the middle of this conflict.

In the first instance, proofing mechanisms outlined above should be adopted, but if unsuccessful calling a professional should be your next action. The professional will have the following control mechanisms in their armoury.

Spring traps

The law states that only approved spring traps must be used and that they are set in natural or artificial tunnels to reduce the risk of killing non-target species.

Live capture traps

The intrusive and inquisitive nature of squirrels means that they can be caught in baited cage traps, albeit some can be trickier to catch than others.

IMPORTANT: Grey squirrels cannot be re-released once caught alive. This is a requirement under the Wildlife and Countryside Act 1981.

Drey poking

Drey poking can be useful, especially on cold winter days. A team effort is needed to work grey poking poles and to cover a tree. With this method, professionals can clear a lot of dreys in a single day. When all the dreys are removed in Winter, it becomes easy to spot new drey nests made in the Summer.

Shooting

Free shooting of grey squirrels can be a useful method of control, especially in early spring when young shoots are showing in trees.

IMPORTANT: Users of air rifles and firearms must have the appropriate skills, experience and training to safely carry out control using these devices.