Hazel dormice reintroduced to Bedfordshire woodland to boost species resilience

Conservationists are trying to bolster the genetic variation and resilience of threatened hazel dormice as they release 10 of the tiny mammals in Bedfordshire.

The rare species have been reintroduced into woodland managed by Forestry England and supported by the Greensand Trust as part of efforts to help the endangered species come back from the brink of extinction.

The new dormice are being released to boost the genetic diversity of Bedfordshire’s only existing population, which has grown after the first species reintroduction in the area in 2001.

The native species, immortalised as the sleepy guest at the Mad Hatter’s Tea Party in Alice in Wonderland, have suffered declines of 70% since 2000 and have disappeared from 20 English counties.

The People’s Trust for Endangered Species (PTES) has been working with the Common Dormouse Captive Breeders Group, ZSL and other partners, to breed the tiny creatures in captivity before releasing them into woodland across the country.

The 10 new dormice were bred in Kent, Dorset, East Sussex and Manchester in the last year before spending eight weeks in quarantine in London.

Cages for dormice reintroduction in a Bedfordshire wood
The nest boxes and cages are prepared for the reintroduction in Bedfordshire (Rebecca Speare-Cole/PA)

After being given a clean bill of health, they were transported to the Bedfordshire site earlier this week.

Here, they were left to acclimatise to their new surroundings from the safety of their nest boxes, which are placed inside larger mesh cages attached to a tree and filled with foliage, buds, berries, nuts and water.

Three females and three males were carefully paired up together in cages to ensure genetic diversity if they breed.

Local volunteers from the Bedfordshire Mammal Group – some who have monitored the population since the 2001 release – will help the dormice settle into their new home by carrying out daily checks.

After 10 days, vets will give them a final health check before the cage doors are opened so they can explore the wider woodland, mingle with the existing population, breed and disperse into new areas.

The dormice were transported from London in nest boxes ahead of their release. (Rebecca Speare-Cole/PA)
The dormice were transported from London in nest boxes ahead of their release (Rebecca Speare-Cole/PA)

The volunteers will then continue long-term monitoring to ensure the population thrives.

The move to strengthen the genetic diversity comes as the UK climate becomes increasingly volatile, experiencing the wettest winter on record.

Ian White, dormouse and training officer at PTES, said more flooding puts hibernating dormice at risk of drowning, while warmer winters can prompt them to wake up too early and wetter summers can disrupt their breeding.

Asked about the wet weather in recent months, he said the full impact on their conservation efforts will not become clear until early next year, but added: “The general trend is downwards I have to say.

A male dormouse set to be released into a Bedfordshire woodland. (Rebecca Speare-Cole/PA)
A male dormouse set to be released into a Bedfordshire woodland (Rebecca Speare-Cole/PA)

“From a climate point of view, there’s not a lot we can do. But what we can do is make the habitat as good as we can to make it as resilient as we can.

“You hate to think about how bad it would be if we weren’t fighting against the declines because it would be worse.”

Neal Armour-Chelu, district ecologist from Forestry England who helps to manage Bedfordshire woodland, said the species are a “good indicator species” for biodiversity and a “bellwether for forest habitat management”.

“It is great to know that the single Bedfordshire dormouse population is thriving, thanks to the continued work of the PTES and two decades of monitoring carried by the Bedfordshire Mammal Group,” he said.

“Dormice love coppice and we are looking to continue this special type of woodland management for the benefit of the woodland’s special wildlife.”

Mr Armour-Chelu said agri-environment incentives can also support neighbouring landowners with dormice conservation efforts so populations do not remain isolated.

“You begin to get a more connected landscape so these animals can move through,” he said. “It’s about resilience and the ability to adapt to the environment that’s shifting and changing potentially for the worst going forward. So it’s giving them the genetic tools to adapt.”

“We’d be a lot poorer for not having dormice,” he said. “They’re a classic woodland animal. It would be heartbreaking.”

In June, another 10 dormice will be released into a woodland in Lancashire owned by Natural England, also to build on a previous reintroduction which took place in 2021.