Other Mammals
Grey Squirrels
Grey squirrels (Sciurus carolinensis) are invasive pests, not native to the UK.
They were first introduced to the UK from North America in the 1870’s, as ornamental additions to high-class estates and country homes.
Introductions continued until the 1930’s, when the damage they can cause was finally acknowledged and it became illegal to release grey squirrels into the wild.
The dangers: why we control grey squirrels
Even though the grey squirrel is widely appreciated for its grace and ‘cuteness’ by much of the UK – the pest management industry knows that there are times when the lethal control of grey squirrels is necessary.
The grey squirrel is recognised as being in the top worst 100 invasive pest species in the world by the International Union for Conservation of Nature (IUCN).
Here in Britain and Europe, is classed as an Invasive Alien Species (IAS) which is any animal that is not native to the UK.
Because grey squirrels are an invasive pest species, it is against the law to re-release a grey squirrel if it’s been caught alive, per the Wildlife and Countryside Act 1981 and Invasive Alien Species (Enforcement and Permitting) Order 2019.
That means that any person who catches a grey squirrel alive is legally obliged to humanely dispatch it.
Squirrel damage in your home, business and to your health
Grey squirrels can cause damage when they enter roof spaces of houses and buildings. For example, they can:
Gnaw on woodwork and ceilings
Strip insulation from electrical wires
Tear up fibreglass insulation
Contaminate cold water tanks and attic space with urine and droppings.
People also report sleep issues due to the loud noises they make at night while they’re scuttling around your attic.
Squirrels are most active before sunrise, especially in winter. Their peak activity is activity is four-five hours before daybreak.
Grey squirrels often associate humans with food, meaning they sometime approach people. Some people fear being attacked, however it’s very rare for a squirrel to actually attack!
In gardens and allotments, they can take fruit, raid nests of small birds and dig holes in lawns to bury food.
Grey squirrels and UK forests
Grey squirrels cause damage to trees such as beech, oak and chestnut. They strip bark at the base of trees which causes them to weaken and eventually to die.
Grey squirrels also:
Raid birds’ nests to prey on eggs and fledglings (figures from the Game and Wildlife Conservation Trust suggest fledgling rates reduced by 15% due to predation by grey squirrels)
Damage orchards and gardens, destroying bulbs and corms, eating tree nuts and recently sown seeds
Wreak havoc on historic and ancient woodlands.
The native red squirrel vs invasive grey squirrels
The grey squirrel was deliberately introduced to England, Wales, Scotland and Northern Ireland from North America in the Victorian era. Since then, it’s colonised 90% of England and Wales and is becoming a problem in Scotland.
Grey squirrels are responsible for the decline in native red squirrel (Sciurus vulgaris) numbers.
The Wildlife Trusts estimates there are only around 140,000 native red squirrels left in the UK, compared to 2.5 million grey squirrels.
Foxes
Many people are concerned about foxes affected by mange. A scruffy looking fox is not necessarily an ill fox. When moulting in spring, foxes look quite rough, but this does not mean they are mangy. They are typically found in woodland and open country, but their presence in urban areas is increasing. Red foxes are opportunist feeders and eat insects, earthworms, fruit, berries, wild birds, small mammals and scraps left by humans.
Red foxes are primarily active at dusk and night. They are solitary, but they very occasionally group together in a pack.
Foxes forage alone in different parts of their territory, which may extend from 25 to 5,000 acres, depending on the habitat. They use faeces and urine to mark territories.
Reproduction
Vixens come into heat once a year for one-six days. They give birth to four-seven cubs in a den (also called an earth), after a gestation period of 51-53 days. The cubs are weaned at seven to nine weeks and become sexually mature after a year. The number of cubs and the time of year in which the vixen gives birth depends on food availability.
Feral Cats
Feral cat (or stray cat, alley cat) is a cat which has been separated from domestication through abandonment, loss, or running away, and becomes wild. The term may also refer to descendants of such cats, but not to wild cats, whose ancestors were never domesticated.
Feral cats may live alone but are usually found in large groups called feral colonies.
Feral cats are not killed, but instead trapped and normally spayed and rereleased to prevent the population increasing. This is normally carried out by or with assistance from the RSPCA.
Voles
Usually confused with Brown Rats, these small, blunt-nosed rodents can occasionally enter buildings, but normally live in outdoor burrows. Not regarded as a household pest, and in fact, some species such as the water vole are a protected species and cannot be harmed.