Grey squirrels must be controlled because they damage UK woodlands, endanger native red squirrels, harm wildlife, and cause significant property problems.

The Threat to Red Squirrels

Grey squirrels were introduced to the UK in the late 19th century and have pushed native red squirrels out of most of England and Wales. They out‑compete red squirrels for food and habitat, and they carry squirrelpox virus, which is usually fatal to red squirrels while leaving greys unharmed. In areas where grey squirrel numbers have been reduced, red squirrel populations have stabilised or begun to recover. With red squirrels now endangered and their numbers extremely low, controlling grey squirrels is essential for their long‑term survival.

Damage to Woodlands

Grey squirrels strip bark from trees such as beech, oak, sycamore, and chestnut. This weakens or kills trees, reduces timber quality, and discourages landowners from planting broadleaf woodlands. Bark stripping also disrupts woodland ecosystems by affecting fungi, insects, and other species that depend on healthy trees. Surveys across England show widespread damage, and the economic cost to woodlands in England and Wales is estimated in the tens of millions of pounds each year.

Impacts on Wildlife

Grey squirrels do more than harm trees—they also affect other wildlife. They raid nests, taking eggs and young birds, and their presence has been linked to declines in songbird numbers. They may also disturb dormice and other small mammals. Their ability to eat unripe nuts gives them a competitive advantage over native species, further reducing biodiversity.

Property and Safety Problems

Grey squirrels frequently enter lofts and buildings, where they chew wood, insulation, and electrical cables. Damaged wiring can create a serious fire risk. They may contaminate water tanks, cause structural damage, and create noise disturbances. Because they are classified as an invasive pest species, it is illegal to release a trapped grey squirrel, making proper management essential.

Why Ongoing Control Is Necessary

Grey squirrels thrive in the UK due to abundant food, limited predators, and rapid reproduction. Even when numbers are reduced in one area, they quickly recolonise it. With millions of grey squirrels across Great Britain, unmanaged populations continue to grow and intensify their impact on woodlands, wildlife, and property.

Long‑Term Strategy

The UK’s approach to grey squirrel management includes reducing populations to protect red squirrels and woodlands, supporting landowners with training and resources, and researching new methods such as fertility control. In some regions, the recovery of pine martens—a natural predator—has also helped reduce grey squirrel numbers.

Summary

Grey squirrels need to be controlled because they:

  • Endanger native red squirrels through competition and disease.

  • Damage and kill trees, harming woodland health and biodiversity.

  • Reduce populations of birds and other wildlife.

  • Cause costly and dangerous property damage.

  • Are a non‑native invasive species with few natural predators.