Over 40 rare Hazel Dormice have been reintroduced into a Leicestershire woodland by People’s Trust for Endangered Species (PTES) and partners. 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 the 2025 reintroduction in the same woodland, this further release boosts numbers and genetic diversity, helping to restore a native species that has declined by over 70% nationally since 2000.
Last year, 21 Hazel Dormice were released by PTES and partners 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 a 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.
Ian White, Dormouse & Training Officer at People’s Trust for Endangered Species explains:
“Hazel dormice have declined by over 70% nationally since 2000 due to habitat loss, poor woodland and hedgerow management and climate change. These figures are extremely concerning, but over the past 30 years our reintroduction programme, alongside habitat restoration, sympathetic woodland management and monitoring, is giving this threatened species a real chance of recovery. And, on a local level, by releasing more dormice into Bradgate Park this week, we are one step closer to creating a larger, connected population that hopefully will one day span the whole National Forest, giving further cause for hope.”
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 released. There was evidence of breeding too, with 11 young recorded in August and 15 in September.
The reintroduction programme
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.
The reintroduction programme depends on a unique partnership between several organisations. All Dormice released are bred by members of the Common Dormouse Captive Breeders Group, with the majority of this year’s Dormice provided by key member Wildwood Trust following its most successful breeding season to date.
Before release, all Dormice undergo a thorough nose-to-tail health check by wildlife vets at Whipsnade Zoo in Bedfordshire, Paignton Zoo in Devon and Twycross Zoo in the East Midlands. This four-week quarantine period ensures all Dormice are fit for release and don’t carry any diseases that could pose a risk to local wildlife. Once given a clean bill of health, they’re carefully transported to their new woodland home for release.
The location of this year’s woodland was carefully selected with the help of the Leicestershire & Rutland Wildlife Trust, the Leicestershire & Rutland Mammal Group, the National Forest and Twycross Zoo.
A unique British mammal
Hazel Dormice are the only small British mammal with a furry tail, and with their golden-brown fur, large black eyes and long whiskers, are very endearing. They’re nocturnal animals that are active from late spring into summer and autumn, spending much of their time in tree and shrub canopies, and hibernate over winter in nests on the ground. Their long-term decline reflects the loss of many old woodlands over the last century, the lack of management of those that are left, and the removal and neglect of hedgerows no longer needed to enclose livestock.
Find out more about PTES’ dormouse conservation work.
Data on the NBN Atlas
You can view the data held on the NBN Atlas for Hazel Dormice here. With around 60,000 records of Muscardinus avellanarius, 43,000+ are from the National Dormouse Database and the remaining records from other data partners. Without this vital data the national picture would be much less clear.
