Home / Environment / Bumper Crop Triggers Surge in UK's Invasive Grey Squirrel Population
Bumper Crop Triggers Surge in UK's Invasive Grey Squirrel Population
15 Nov, 2025
Summary
- 2025 expected to be "mast" year for trees, providing abundant food for grey squirrels
- Grey squirrel populations to increase, causing more damage to trees through bark stripping
- Endangered native red squirrels to face greater threat from the invasive greys
According to a recent report, the UK is bracing for a surge in its invasive grey squirrel population in 2025. Experts predict that this year will be a "mast" year, meaning certain tree species like oaks, beeches, hazels, and chestnuts will produce an abundant crop of nuts and seeds. This abundant food supply is expected to support larger grey squirrel populations through the winter and provide more resources for breeding, leading to a significant increase in their numbers.
As the grey squirrel population grows, so too will the damage they cause to trees, particularly through bark stripping. This activity primarily occurs between April and October, when the larger and more aggressive grey squirrels are most active. The Royal Forestry Society estimates this damage could cost at least £1.1 billion over the next 40 years in England and Wales alone.
