Management of grey squirrels
Summary
Since their introduction into Britain between 1876 and the 1920’s, grey squirrels have spread rapidly, gradually displacing the native red squirrel in most of England and Wales, and in central and south-east Scotland.
Grey squirrels are extremely destructive in woodlands, stripping bark from the main stem and branches of trees.
Red and grey squirrel distribution from 1998 data 
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Research objectives
The overall aims of this research programme included:
- Investigating the impact of grey squirrels on woodlands and the reasons for bark stripping behaviour
- Identifying efficient control strategies, including new trapping methods, contraception and natural predation
- Promoting and supporting best practice management for the control of grey squirrels and their impacts.
Specific objectives included:
- Support evidence based policy development at national and regional levels
- Investigating the hypothesis that bark stripping behaviour by grey squirrels may be motivated by a calcium deficiency in their diet.
- Assessing impacts of the introduced grey squirrel on sustainable woodland management
- Investigate changes in numbers and behaviour of grey squirrels in response to pine martens
- Investigating novel and develop improved methods of population control, including reviewing the potential use of attractants
- Monitoring developments (worldwide) in the use of immuno-contraceptives for mammal population control, and consider their potential application to grey squirrel control (see reproductive inhibition in grey squirrels)
- Investigating alternative methods of damage limitation such as stand management, and the development of physical and chemical deterrents
- Providing practical advice to the forest industry and the general public and promote best practice by supporting training seminars and workshops on grey squirrel control for woodland owners and managers.
Funding and partners
This research is funded by the Forestry Commission Vertebrate management programme. This includes an annual summary of the research.
What's of interest
"Invasive species, threatening biodiversity in Europe"
IAS news video
Related pages
- UK Red Squirrel Group (UKRSG)
- Grey squirrels and Phytophthora ramorum
- Mammal damage to trees and woodland
- Red squirrels - species action plan research
Useful sites
- Squirrel Web
- U.K. Biodiversity Action Plan
- National Biodiversity Network Gateway
- Trapping pest mammals - traps and legislation
Further reading
Forestry Commission and other publications covering the management of grey squirrels. Some are available for downloading.