A breakthrough in the creation of an oral contraceptive for wildlife has been made by British researchers – in a significant step towards ethical grey squirrel management. Scientists at the Animal and Plant Health Agency (APHA) have achieved infertility in rats through free feeding of an oral immunocontraceptive, and say initial studies show the formula has also succeeded in attaining a reaction in grey squirrels. Funded by the UK Squirrel Accord (UKSA), the research will develop a vaccine-based contraceptive and species-specific feeder to reduce grey squirrel numbers for the protection of UK red squirrels, trees and woodland ecosystems. …Fertility control is used as a safe and non-lethal option to tackle wildlife problems. …This contraceptive affects an animal’s immune system to prevent it creating the sex hormones and causes infertility in both males and females. Developing a formula that can survive the body’s digestive processes and make it into the bloodstream is a real challenge.