National Dormouse Conference 2023

The Peoples’ Trust for Endangered Species (PTES) collates and analyses any records sent in from many counties and sites which are part of the National Dormouse Monitoring Project (NDMP). The registered sites record any nests found in the boxes and the abundance, sex, weight and breeding condition of any dormice found in them, or the lack of them. The sites in the project are checked by people who hold a licence to do so, mainly volunteers. The licence is a requirement from Natural England, as dormice are classified as ‘Vulnerable’. 

I started a dormouse monitoring site about 15 years ago in Oysters Coppice and Gutch Common, with new boxes being added progressively. We check the 173 boxes once a month from April to November and the records are sent to PTES. We had none in Oysters Coppice but a few in Gutch Common wood this year.

On 11th November, I attended the 2023 Dormouse conference in Reading. Here are some of the notes I took.

Ian White, from PTES, gave an up-to-date report about the state of Britain’s dormice (you can read the full report here). They have declined by 70% in monitoring sites since 2000 and are on the verge of being reclassified as ‘endangered’. However, they are known to live along roads and railways, in dense scrub and in conifer forests, so there may be more than are known.

In the last century, there were dormice in all but two counties in England and Wales. In this century, they have become extinct in twenty counties. Some captive bred dormice have been reintroduced successfully in some of these. Reasons for the decline in dormice:

• Loss of habitat (e.g. managed woodlands and hedges; wildlife corridors between patches of woodland and hedges).
• Climate change. For instance in warm winters dormice will awake from hibernation when there is no food or they could get flooded out from incessant rain during hibernation in leaf litter, under trees, etc.
• Disturbance from people or dogs.
• Predation from badgers, stoats, etc.

I also found very interesting a presentation given by Leo Gubert on hibernation. Leo tried, unsuccessfully, to train dogs to sniff out dormant dormice for the purpose of surveying. Adults may hibernate between December and March, although juveniles born in August/September may not hibernate until late in the winter in order to gain weight before hibernation. Only about 30% survive hibernation. Dormice weave their hibernation nests from materials found within 4 Km of boxes and use materials found close by from leaf litter, honeysuckle bark, grass, fern and bracken. Some use tree holes or squirrels’ dreys.

How to survey for dormice? Survey methods frequently used:

• Tubes hung at checking height (more successful high up) in hazel bushes or other trees, scrub and hedges to check for nests or mice. Boxes fixed to trees with holes at back to look for nests or dormice.
• Footprint tunnels with ink pads on each side of white paper. Dormice footprints are unique and can be distinguished from woodmice.
• Radio collars…. This is expensive!

What can we do for dormice? Here is a list of some conservation efforts:

• Survey in unusual habitats like dense scrub, hedges, sea cliffs, conifer forests, roadsides and high-up in tree canopies (ladders needed).
• Improve connectivity between woodlands and hedges.
• Extend woodlands by planting more trees and connecting them by planting hedges with native plants full of berries, nuts, flowers (all of which are food sources for dormice).
• Reduce disturbance by people and dogs.

Most of these facts come from the Dormouse conference but some opinions are mine (Debbie Carter 2023). Ed.: Our society has two dormouse survey licence holders and are willing to assist any local prospective surveyors in starting out a new surveying or monitoring project.

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