Animal and Plant Health Agency (APHA) researchers funded by the UK Squirrel Accord (UKSA) and supporters attained a world first for wildlife fertility control. Positive news for a programme aiming to find a non-lethal option for invasive grey squirrel management.
The multi-year research programme being delivered by APHA has resulted in a scientific breakthrough by achieving infertility in rats through free feeding of an oral immunocontraceptive – a world first. The research ultimately aims to 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. The formula has also succeeded in achieving a reaction in grey squirrels and research is ongoing to refine the formula to increase effectiveness.
Fertility control is increasingly used around the world as a safe and non-lethal option to tackle wildlife problems. The APHA team is redesigning injectable immunocontraceptive vaccine technology, already used to manage other mammals, into an oral formula that can be delivered via feeding hoppers only accessible by grey squirrels. 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 still make it into the bloodstream is a real challenge. A key part of the research is combining the contraceptive with components that provide protection before delivery through the lining of the gut. The research does this using natural capsules made from plant spores created by Sporomex Ltd – a technique already used in clinical studies to deliver vitamin D to human volunteers. These capsules protect the active contraceptive ingredient while also being kind to the environment.
APHA is also collaborating with experts from the Roslin Institute and MV Diagnostics to increase the scale and duration of the effect of the immunocontraceptive vaccine to make it suitable for use in the wild. The final product must remain stable and effective once put into the species-specific feeder. The feeders being developed include one with a weighing platform that electronically opens the door only if the animal is within a certain weight range. This makes it specific to adult grey squirrels, which are heavier than reds.
Research of this scale would not be possible without the generosity of contributions from UKSA signatories, grant-making organisations and private individuals and estates. The donors are motivated by their understanding of the benefits of a new management method for UK grey squirrels. As well as wider potential opportunities for problematic mammal species management.
Lord Kinnoull, Chair of the UK Squirrel Accord, said: “This is a major step forward for our research. We understand that many people want to see this product available tomorrow. However, we must ensure that what is created is effective and that takes time. This will be the world’s first oral free-feeding immunocontraceptive and its potential for mammal management is significant”.
Bex Pinkham, Mammal Subject Lead for the Animal and Plant Health Agency said: “I’m really encouraged by the progress we’ve made in our research so far as part of this important partnership project. These breakthroughs are a positive step forward towards a grey squirrel management tool that will mean so much for our UK woodlands.”
MV Diagnostics said: “We are excited to be involved in this groundbreaking research. Developing an immunocontraceptive that could be used in this way has major implications for the ethical control of problem mammals”.
Vanessa Fawcett, Red Squirrel Survival Trust Campaign Director, said: “Fundraising has begun for the next stage of this groundbreaking research project, to bring an effective and affordable grey squirrel oral fertility control system to market. Active dialogue is underway with current donors and new donors are being sought, to support the further refinement and development of the vital work being done at the Animal & Plant Health Agency. Our vision is for our native red squirrel populations to be secure and expanded beyond their current strongholds, and to see our woodlands flourishing, continuing to deliver multiple benefits for future generations.”
For further information or questions please email kay.haw@squirrelaccord.uk.
