Grey squirrel management

Grey squirrel bark stripping a tree by Gillian Pullinger

Grey squirrels are managed to protect red squirrel populations and to prevent them damaging and killing broadleaf trees.

Grey squirrels are native to North America, but were intentionally introduced to a number of sites in England and Ireland between 1876 and 1929. After establishing viable populations, they started to spread and cause problems. In 1937, a law was passed prohibiting their importation and keeping in Great Britain. They are now classed as a UK invasive non-native species (invasive alien species in the EU) due to their negative impacts.

Mammal Society estimates put their population at around 2.7 million individuals, although there is no definitive figure. They are now widely spread in large areas of England, Wales, the Scottish Lowlands, Northern Ireland and Ireland, where they tend to live at higher densities than the native red squirrel. They have serious negative impacts on red squirrel numbers (causing local extinctions) through competition and disease transmission, and bark strip young trees causing major damage and tree fatalities.

Management methods

Land managers, conservationists and volunteers currently use approved trapping or shooting methods to humanely manage grey squirrel numbers. However, the UK Squirrel Accord is fundraising for research into a fertility control that would offer an effective and less labour intensive non-lethal management method. Management, of all types, of grey squirrels on any land requires the landowner’s permission.


British Red Squirrel, with support from the Animal and Plant Health Agency, has compiled a list of licensed traps legally available for grey squirrel management. Please note, lethal traps should not be used in areas of crossover between grey and red squirrels nor in red squirrel strongholds. However, live traps are also available. There are also some differences in legislation between the different UK countries and further guidance should be sought from the relevant licensing body.


The use of air rifles is another method for managing grey squirrel numbers. The British Association for Shooting and Conservation is currently working with Natural Resources Wales to manage grey squirrel numbers in red squirrel areas, including supporting the Mid-Wales Red Squirrel Project.

Lantra has developed a training course for shooting grey squirrels for red squirrel conservation. ‘This course offers suitable individuals the opportunity to provide the evidence to support they are competent to be permitted to enter private land in possession of an air rifle and to cull grey squirrels in order to conserve red squirrels.

Fertility control research

The UK Squirrel Accord is fundraising for research into an effective oral contraceptive and species-specific delivery mechanism for grey squirrels. Work is being carried out by the Animal and Plant Health Agency and we are in the third of the five-year project. Find out more on our fertility control research page or donate here to support the project.