The dormouse is protected by UK and European legislation making it illegal to.

intentionally kill, injure or take a Dormouse;

possess live or dead animals or any parts thereof;

intentionally or recklessly damage, destroy or obstruct access to any place used for shelter or protection by a Dormouse or to disturb a Dormouse whilst it is using such a place;

sell, offer for sale, possess or transport for the purpose of sale any live or dead animal or part thereof.

Dormouse (Muscardinus avellanarius)

The dormouse is found mainly in the south of England. They have golden brown fur on their backs and a pale cream coloured underside with large protruding black eyes. The dormouse can be easily distinguished from other UK rodents because of its completely fur covered tail. Its preferred habitat is ancient semi natural woodland with a wide variety of nut and fruit bearing trees and shrubs. Untrimmed unmanaged hedgerows are also good habitat for the dormouse and act as a connectivity feature between different foraging habitats. Dormice are strictly nocturnal and spend most of the day in spherical nests a few feet above the ground. The nests are made from shredded honeysuckle bark and grass. Dormice are arboreal, and will spend most of their time in the branches, rarely using the ground. Dormice are well known for their habit of sleeping most of the time. They construct a nest close to the ground in October and curl up in a ball and sleep through till April or May. If the weather is cold through the summer or if food is scarce the dormouse will save energy by going into a state of torpor. Dormice have been known to hibernate for as much as seven months of the year.


Dormice feed on a variety of food found high up in the trees. They will eat flowers and pollen during the spring, fruits and berries through the summer months and nuts (particularly hazel nuts) in the autumn. They will also occasionally take insects. All of this food must be found within a small area as they only travel within 70m of their nest.


Dormice populations have been in serious decline in recent years. The main reasons for this are habitat loss, inappropriate woodland management, and isolation of suitable habitats. Isolation of habitats has been caused by (among other things) the removal of hedgerows.

What can you do?

An Extended phase 1 habitat survey prior to the start of any works on site will broadly identify dormouse habitats. Further more detailed survey work may be required to identify numbers and the extent of the habitat.

When considering planning applications, the authorities are required by law to take account of protected species and the conservation of habitats. A detailed ecological survey is usually required before planning permission can be granted.


Case Studies

Phase 1 Habitat Survey in Winchester

November 2011
UES recently completed an Extended Phase 1 Habitat Survey of an old mill in Winchester. An Extended Phase 1 Habitat Survey involves mapping the habitats on the ... more...

Dormouse survey in Oxfordshire

September 2011
UES have recently completed a dormouse survey of a site in Oxfordshire. The proposed development involves the removal of a number of trees along a woodland edge... more...

Extended phase 1 habitat survey in Deeside

August 2011
UES have completed an extended phase 1 habitat survey of a site in Deeside, North Wales in order to inform the client of any potential impacts their development... more...

Extended phase 1 survey in Oxfordshire

June 2011
UES have completed an extended phase 1 habitat survey of a site in Oxfordshire in order to inform the client of any potential impacts their development would ha... more...

Great crested newt trapping scheme

November 2010
Project summary In 2008/09, UES were instructed to conduct a Great Crested Newt (GCN) mitigation scheme for Augean PLC at Slipe Clay pits in King’s Cliffe, n... more...

Breeam Habitat Survey in Birmingham

November 2010
UES were commissioned to provide an Extended Phase 1 Habitat Survey of o high rise office complex near Edgbaston in Birmingham. The Survey is to provide informa... more...