Forestry England is helping hazel dormice travel safely between woodlands by building rope bridges! The creative solution comes after the removal of diseased ash trees from a woodland in Flaxley, in the Forest of Dean, left the endearing mammals’ habitats disconnected. 

Dormouse bridge
A dormouse bridge (Forestry England)

In an effort to re-link them Forestry England has built two 20 metre long bridges 16 feet high over a forest road and supported between trees. Area ecologist at Forestry England, Kate Wollen said: “Dormice do not like to come to ground except for hibernation. They feel vulnerable to predators when on the ground and while these bridges do not replace the trees that had to be felled, they will enable dormice to feel safer as they cross from one part of the wood to another.” 

Hazel dormice need woodland or hedgerow trees and shrubs to live and feed during the warmer months and rarely come to the ground, preferring to travel around underneath treetops or shrub cover. 

Chalara ash dieback, caused by a fungus called Hymenoscyphus fraxineus, developed among a section of trees where dormice are monitored. The fungus blocks the tree’s water transport system, causing leaf loss, and lesions in the wood and on the bark. This causes the crown of the tree to die back. 

Trees become brittle over time with branches breaking away from the tree. If left untreated, trees can potentially collapse, presenting an immediate danger to the surrounding area. Whilst the hazel dormouse population has declined across the country, the Forest of Dean remains an important habitat for these tiny creatures. 

The bridges took less than two days to install and over the summer trail cameras will be fitted to monitor the dormice using them. 

Bridge
The dormouse bridge ready to be set up (Forestry England)

Community ranger Leoni Dawson added: “We could not have accomplished this project without the help of our volunteers. Together we have worked very hard in this woodland improving habitat for the wildlife and flora. We also have a volunteer who has been surveying for dormice here for over 20 years! 

“We hope the bridges will complement this work and that dormice will do well. We’ve never tried this before and it is exciting to see what will happen.”