Twycross Zoo Reintroduces Hazel Dormice to Bradgate Park for a Second Year
9th Jun 2026
This week, in partnership with People's Trust for Endangered Species (PTES) and other collaborators, we reintroduced 40 hazel dormice into a Leicestershire woodland. This release is part of PTES' ongoing national reintroduction programme which, for over 30 years, has been restoring this declining native species to woodlands across Britain in a bid to save dormice from extinction.
Building on last year's successful reintroduction, we're proud to have cared for 20 of these dormice through their quarantine period, and are thrilled to see them now heading back into the same woodland to strengthen both numbers and genetic diversity.
Last year 21 tiny golden-coated mammals were released into the same woodland on the Bradgate Park Trust estate, creating Leicestershire's only known population. The estate boasts some of the best remaining ancient woodland in the county, and is both a Site of Special Scientific Interest and part of National Nature Reserve. Although the dormice released last year have bred and appear to be settling into their new home, more dormice have been released to increase numbers and boost genetic diversity, helping to restore a native species that has declined by over 70% nationally since 2000
Since their release in June 2025, local volunteers and rangers have been regularly monitoring the dormice using nest boxes at Bradgate Park. These boxes help keep tabs on the reintroduced population and reveal evidence of breeding. Encouragingly, the team has found a growing number of dormouse nests across the woodland, reflecting the growing population. 46 dormice were found in the October 2025 check - double the number of animals initially release, with 11 young recording in August and 15 in September.
James Dymond, Director, Bradgate Park Trust said: “We’re hugely encouraged by how well last year’s dormice have settled into their new home, and to know there is evidence of breeding is extremely gratifying for everyone involved in both the release and ongoing monitoring. We’re thrilled that more dormice will be joining our existing population this year, and look forward to another summer of nest box checks supported by our fantastic volunteers and, hopefully, finding more evidence of breeding as a
result.”
PTES’ annual dormouse reintroductions are part of Natural England’s Species Recovery Programme, and since the programme began in 1993, 1,163 dormice have been released into 27 different woodlands in 14 counties across Britain.
Before release, all dormice underwent a thorough nose-to-tail health check by our on-site wildlife vets here at Twycross Zoo, as well as vets from Whipsnade Zoo and Paignton Zoo. The four-week quarantine period ensures all dormice are fit for release and don't carry any disease that could pose a risk to local wildlife. Once given a clean bill of health, they were carefully transported to their new woodland home for release.
As with last year, on reintroduction day the dormice were placed into nest boxes which were put into a large mesh enclosure filled with natural food, foliage and water, mimicking the wider woodland. Volunteers monitor the dormice daily from this point, replenishing their food and water supplies, and during this time the dormice can adjust to the sights, sounds and smells of their new woodland home from the safety of their enclosures. Then, after ten days, our zoo's veterinary team will return for a final health check before the doors to their enclosure are opened and the dormice are free to explore the woodland, breed and eventually spread to neighbouring areas.
We're excited to be apart of this project alongside PTES, Leicestershire Rutland Wildlife Trust, the Leicestershire Rutland Mammal Group, the National Forest, as well as other partners.
In 2023, we pledged to reverse the decline of 15 species who were at risk of extinction. The hazel dormouse was one of them. As a species that was thought to be extinct in Leicestershire until last year, projects like this our vital to conserving our native species.
