Hazel dormice reintroduced into Derbyshire woodland

Nearly 40 of the furry rodents are being slowly released into scrub where they will feed on fruit, nuts and insects.
Nearly 40 of the furry rodents are being slowly released into scrub where they will feed on fruit, nuts and insects. Nearly 40 of the furry rodents are being slowly released into scrub where they will feed on fruit, nuts and insects.

A group of 38 hazel dormice are being reintroduced into a Derbyshire woodland as conservationists hope to turn around the decline of the species.

The population in Britain has fallen by around half since 2000 and they are now classed as vulnerable on the Red List for Britain’s mammals.

Volunteers from the People’s Trust for Endangered Species (PTES), along with ZSL Paignton Zoo and other partners, are slowly releasing the tiny creatures into woodland owned by the National Trust.

They have just spent eight weeks in quarantine and have now been paired up to spend a further 10 days in a wooden bird house-like box inside a cage attached to a tree while they acclimatise to their environment.

Ian White, dormouse and training officer at PTES, said: “They’ll be put in the cages, the cages are then sealed up and the dormice are left there for about 10 days just to become used to the sight and sound of their new home.

Twiglet and grape in bag
Twiglet and grape in bag Twiglet, like the other hazel dormice, has been fed a diet of fruit, corn and bird mix while in quarantine (James Beck/National Trust/PA) (National Trust/James Beck)

“And then after 10 days, a small opening will be made in the cages and then the dormice are free to come and go.

“Dormice are relatively sedentary, they don’t move very far, so an area equivalent to about half a football pitch will take one dormouse.”

He said they have been fed on a diet of corn, fruit and bird feed while in quarantine but in the wild they will eat honeysuckle and bramble flowers, hazelnuts, and invertebrates living on oak trees.

Mr White added: “Two things dormice need, a fairly diverse range of food species, so old woodlands where you have got a range of trees, a range of different plants that they can feed on is important.

“And also because they are fully arboreal when they’re active they need connectivity, the kind of tree and shrub level to enable them to get around, which is why you need ongoing management.”

The rodents are active mostly at night and hibernate for five months over the winter, having built their nests from strips of bark.

Because of this, they only produce one litter of four offspring each year and they grow to between 6-7cm when fully grown.

NT volunteers
NT volunteers Volunteers wore PPE to protect the dormice as they put them in their cages (James Beck/National Trust/PA) (National Trust/James Beck)

The current dormouse reintroduction is the 26th done by PTES since the 1990s and about half have been successful, Mr White said. Success depends on how well the woodland is managed, before and after the reintroduction.

Jon Lewney, countryside manager at the National Trust, said his organisation has been managing their woodland, on the Calke Abbey estate south of Derby, for around 10 years in preparation for the dormice.

He said: “What we’ve been looking for is a closed canopy and a shrub layer. So over the years, there has been quite a lot of deer in this woodland and they graze the woodland right down to the ground.

“They get moved on by the public walking through and we have stalkers go through and control the deer as well.

“We’ve got 30 volunteers here today helping out and it’s a really easy sell for volunteers, because they’re so cute and cuddly. And actually it’s easy too for people to engage with them as a species.

“So from our point of view, we’ve been able to get a lot of people involved. Getting people talking about woodland and woodland management, we can actually start to describe why the work we’re doing is important for the National Trust and why it’s specifically important to Calke and the national forests.”