Restoration and research: dormice in a Devon woodland

At Fingle Woods in Devon, we’re monitoring the elusive dormouse to learn how our work to improve the wood’s condition can positively impact this much-loved animal and other wildlife. Find out more about our work there and what we’ve discovered about dormouse activity so far.

Bringing Fingle Woods back to life

The elusive dormouse, often found in its sleepy state, is one of the creatures thriving at Fingle Woods. It’s a stunning ancient woodland on the steep Teign Valley in the fringes of northern Dartmoor. Together with the National Trust, we took ownership of the site in 2015 and began the Bringing Fingle Woods Back to Life project.

In the last century, Fingle was planted with conifer crops. At the time it was an innovative response to the need for timber after the First World War. But the legacy was a woodland left with dense, tall, non-native trees that block out light, leaving the wood in poor ecological condition and reducing biodiversity. This is a common issue, occurring in almost 40% of the UK’s irreplaceable ancient woodland.

It was clear that work needed to start straight away to help this precious place on the road to recovery. To nurse Fingle back to health, we began one of our largest ever woodland restoration projects. Our restoration work here includes:

• gradually thinning the conifer plantations each year.
• creating woodland glades to provide the perfect habitat for insects and butterflies.
• freeing native ancient trees that were hemmed in and suffocated by taller conifers to give them a new lease of life.
• enabling dormant seeds that couldn’t grow in the dark conditions to come to life, helping native trees and plants to naturally regenerate.

Why are dormice important to the restoration?

Right from the start we began monitoring dormice. This special species is classed as vulnerable to extinction, and in the last 18 years, Britain’s dormice population has fallen by 51% (PTES State of Dormice Report 2021).

As a European protected species, we have to survey for dormice before any doing any forestry work. We wanted to find out where they were to make sure our management activity didn’t harm them, but also to understand their habits and habitat requirements.

How are dormice monitored?

We placed nest boxes in key areas at Fingle for licence handlers and volunteers to monitor. 

We have also worked with Masters and PhD students from Exeter University, supporting research to understand how dormice respond to restoration work. Using radio collars and thermal imaging cameras, we’ve been able to track dormouse activity that can’t be observed by nest box monitoring alone.

What have we learned about Fingle’s dormice?

The restored areas are providing the preferred habitat for dormice. The tiny mammals like the variety in tree species, height and age and the vegetation along woodland edges. Different habitats provide a rich larder of berries, flowers, fruits, insects and nuts on which they can feast. We’ve also observed:

• Radio tracking showed dormice spent a lot of time feeding in conifers and piles of brash as well as the broadleaved area. They are likely looking for invertebrates to eat and will return to feeding in the more bountiful larder of the broadleaf area as the restoration progresses.
• Nesting appeared to take place in the broadleaved area where longer strips of fibrous nest material were more available.
• Nests were not found in the conifer area but were common in the transition area between the conifer and broadleaves.
• During very hot summers dormice don’t build nests in nest boxes but use them as they are. This may explain why we didn’t see as many nests that year and indicates a change in behaviour rather then fewer dormice in the area.
• Dormice can quickly adapt alongside woodland management practice. Thermal imaging cameras used in the evening after careful felling took place found dormice in piles of brash created that day. Here they were protected, warm and feeding on an abundance of aphids.

A positive start

Dormice are thriving in Fingle Woods. Our dormice monitor recently discovered a nest in an area of thick scrub that is now developing as part of the restoration process.

We're also surveying and researching many other species of plants and animals as we develop our understanding of the impact of restoration. Though we’re just six years into a long-term restoration project, it’s clear that bringing woods back into good condition can quickly have a positive effect on our wildlife. Other species beginning to flourish include birds like chiffchaff, blackcap, willow warbler and tree pipit. We’re also seeing more butterflies over a wider area, including the pearl bordered fritillary.

Back in 2015, two organisations jointly managing an area of woodland was a unique situation. Without this collaborative approach, the achievements so far would not have been possible. Support from our members, our volunteers, appeal donations and funding from the National Lottery Heritage Fund have also been key. Thank you to everyone involved.

What’s next?

Restoration is a slow and sensitive process so work will continue at Fingle Woods for many more years. We’re still learning too, with a project now underway to monitor dormice footprints. Part-funded by People’s Trust for Endangered Species, this will indicate how individual dormice move around the wood in areas where restoration and regeneration is taking place.

The recent State of UK Woods and Trees report shows us that species are in decline, ancient woods are fragmented and just 7% of Britain’s native woods are in good condition. There is so much more to do to restore our ancient woods and habitats for wildlife here at Fingle, throughout Devon and across the UK.

But projects like this are making a difference. They show what can be achieved in a relatively short space of time. They help us to share our findings and expertise with others. And they give us hope for the future.