Returning dormice to Leicestershire
This week, we’ve reintroduced over 20 rare hazel dormice into a secret woodland location in Leicestershire, creating the county’s only known population of the tiny mammals. This is a landmark conservation effort which will bring rare hazel dormice back to an area where they once existed.
This summer’s release builds on the success of last year’s dormouse reintroduction at NT Calke Abbey. In 2023, 38 dormice were released there – the first time they’ve been brought back to the National Forest. Despite that release being within the forest’s Derbyshire border, this second release is a vital step forward for dormouse recovery nationally and regionally, which will one day form part of a wider population spanning the whole forest.
Taking action before it’s too late
Dormice are considered extinct from 20 English counties and classified as ‘Vulnerable’ on the IUCN Red List for Britain’s Mammals. Conservation projects like this are crucial in helping to reverse their decline – their numbers have dropped by 70% since the year 2000.
Despite once being a common part of Britain’s woodlands and hedgerows, hazel dormice have experienced a catastrophic decline due to habitat loss and degradation, and poor management of woodlands and hedgerows, compounded by a changing climate. PTES’ reintroductions, along with habitat management, landscape-scale projects and monitoring, are paramount to their long-term survival in the UK.
Since the programme began in 1993, we’ve released 1,142 dormice into 26 different woodlands in 13 counties – including six English counties where they had previously been lost. This is a phenomenal achievement and a great step towards restoring hazel dormice to their former range, but it’s only possible with the correct woodland management in place, and of course with the help of our partners and volunteers.
Preparing for release day
Our annual dormouse reintroductions are part of Natural England’s Species Recovery Programme. The wider partnership involves crucial work by the Common Dormouse Captive Breeders Group whose members, including Wildwood Trust, raise captive-bred dormice ready for release.
The dormice are taken to Paignton Zoo, London Zoo, and this year Twycross Zoo, where they have undergone an eight-week quarantine. During this period, the dormice are given a full nose-to-tail health check by wildlife vets 1. This ensures that only healthy dormice are released and that there’s no risk of them transferring diseases or non-native parasites. Once they’re given a clean bill of health, they’re carefully taken to their new woodland home to be released.
On the day of the release, PTES, partners and volunteers gently place the dormice, in their nest boxes, into larger mesh cages filled with foliage, buds, berries, nuts and water where they acclimatise to their new surroundings.
A new woodland home on the Bradgate Park estate
This years’ dormice have been released into a wildlife-friendly and sensitively managed woodland on the Bradgate Park Trust estate, which was carefully selected with the help of the Leicestershire & Rutland Wildlife Trust, the Leicestershire & Rutland Mammal Group, the National Forest and Twycross Zoo. Together we have made sure the woodland is not just ready for dormice now, but will stay that way for years to come, creating the perfect home for dormice and a whole host of woodland species.
Bradgate Park estate is home to some of the best ancient woodland remaining in Leicestershire, which is why it was chosen as the dormice’s new home. The reintroduction of dormice here shows the clear benefit of past woodland management work on the estate, which will be continued for the benefit of not just the new dormice but other rare species too. The dormice will be monitored to ensure that Leicestershire’s only known population thrives and one day expands beyond Bradgate Park.
Local volunteers from Bradgate Park Trust and the Leicestershire & Rutland Mammal Group are instrumental in helping the dormice settle into their new home.
Dedicated volunteers carry out daily checks, making sure the dormice have plenty of food and water. After 10 days, the expert team of wildlife vets from ZSL gives each dormouse a final health check. Then comes the exciting part — the cage doors are opened, giving the dormice the freedom to explore their new woodland home. Over time, they’ll begin to breed and spread into nearby woods and hedgerows, and the mesh cages will be carefully removed.
The dormice will be closely monitored to track how well they’re settling in and to help make sure Leicestershire’s only known population not only survives but thrives. We hope the new population will grow and eventually spread beyond Bradgate Park into the wider landscape.
Footnote 1 including Zoological Society London’s Disease Risk Analysis and Health Surveillance (DRAHS) team.
Image credits Matt Parkins, Robb Doyle, ZSL.