Dormouse Surveys

EMEC Ecology's ecologists have carried out dormouse surveys throughout Great Britain including Nottinghamshire, Lincolnshire, Hampshire, Somerset and North Wales.

The dormouse was once a common sight across much of the UK. However, loss and fragmentation of suitable habitat from increasing development, poor habitat management and intensive hedgerow management have all contributed to a significant decline in populations. As such the dormouse is afforded both National and European protection under Council Directive 92/43/EEC on the Conservation of Natural Habitats and of Wild Fauna and Flora (Habitats Directive), transposed into UK law through the Conservation of Habitats and Species Regulations 2010 (as amended) and the Wildlife and Countryside Act 1981 (as amended). As such it is an offence to: deliberately disturb, capture, injure or kill them; damage or destroy their breeding or resting places; disturb or obstruct access to any place used by them for shelter; possess, or sell a wild dormouse.

Distribution and Habitat

The dormouse has a restricted UK population. They occur mainly in the southern counties especially: Devon, Somerset, Sussex and Kent, but are also patchily distributed across much of Wales, Cheshire, the Midlands and Yorkshire. Although dormice are usually associated with hazel woodlands they occur in a wide variety of habitats including rural gardens, species-rich hedgerows, conifer plantations, wet woodland, dense rhododendron, blackthorn scrub and reed beds. Therefore surveys should not be restricted to optimal habitat and instead should be undertaken in any woody habitat within their known range, which is likely to be affected by works.

Hazel dormice can be affected by various activities including: woodland and hedgerow management, the removal of hedgerows, woodland clearance, noise and lighting. In the majority of cases sensitive management can help prevent harm to dormice or their habitats, however, if this cannot be avoided a mitigation licence from the relevant Statutory Nature Conservation Organisation will be required. EMEC Ecology can carry out dormouse surveys, mitigation and licensing.

If you require a quotation for a dormouse survey please send an email to us at mail@emec-ecology.co.uk including any site plans that you have available (or details and photographs of the site if applicable) with details of the proposed works, along with your contact details. Should you wish to contact us at the office a project involving dormice, please call 0115 964 4828.

Dormouse Survey Methodology

Habitat Assessment

Prior to undertaking a dormouse survey a preliminary habitat assessment will be undertaken by an experienced ecologist and the local biological records centre will be consulted to determine if dormice are present in the vicinity.

Surveying for Dormouse Evidence

The following methods may then be utilised in order to survey for dormice:

  • Nut searches
  • Searching for wild nests
  • Nest-tube and nest-box surveys

Survey Timings

Dormouse surveys should be carried out during the active season, usually April to November. After this period the dormice enter hibernation. Nut hunts can be carried out at any time of the year however they are best undertaken between September and December as the distinctive gnaw-marks can deteriorate over time. This method is restricted to habitats with hazel, and should not be used as evidence of dormouse absence.

The above information is also available as a PDf document. Dormouse Survey - Information Sheet.

Dormouse Mitigation

Dependent upon the development proposals and the survey results, a variety of mitigation solutions may be proposed by EMEC Ecology. Some mitigation strategies must be undertaken under a European Protected Species (EPS) licence, which EMEC Ecology can apply for on behalf of the client.

Appropriate Timing of Works

Works are scheduled for when dormice are least likely to be disturbed. Typically the main window for vegetation clearance is during the winter months (November - March). However, removal of stumps and roots should be undertaken subsequent to above-ground clearance work, during the dormouse active period (May - September) to avoid damaging hibernation sites. Site works are usually supervised by an ecologist during the initial phases to ensure that no dormice are harmed in the unlikely event that they are present.

Creation and Enhancement of Habitat

The ideal solution to the presence of dormice within a development site is to maintain suitable habitat within the new development, However, this option is not always possible and therefore a number of measures can be undertaken to create new or enhance existing dormouse habitat including:

  • Creating wildlife corridors to link isolated habitats by planting native trees and shrubs
  • Planting new woodland with a diverse mix of native species
  • Undertaking sensitive woodland management to reduce shade and encourage understorey growth and increase fruiting
  • Restoring derelict coppice
  • Installing dormouse nest-boxes to replace lost nesting places