Hazel Dormouse Surveys

Dormouse Surveys in Pembrokeshire and South West Wales 

BM Ecology provides professional hazel dormouse (Muscardinus avellanarius) surveys, assessments and mitigation advice to support planning applications and development projects throughout Pembrokeshire and South West Wales.

Hazel dormice are a legally protected species that inhabit a range of habitats, including woodland, hedgerows and dense scrub. Where suitable habitats may be affected by development, ecological surveys may be required to establish the presence or likely absence of dormice and inform appropriate mitigation measures.

When Are Dormouse Surveys Required? 

Dormouse surveys may be required where proposed developments could affect suitable habitat, particularly where woodland, hedgerows or scrub are to be removed or disturbed.

An initial Preliminary Ecological Appraisal (PEA) can identify habitats suitable for dormice and determine whether further surveys are necessary.

Where further assessment is required, BM Ecology can undertake targeted surveys to establish the presence or likely absence of dormice and inform the planning process.

Dormouse Survey Methods 

A range of survey techniques can be used to investigate the presence or likely absence of hazel dormice. The most appropriate method depends on the habitats present, the nature of the proposed development and the time of year.

Dormouse Nest Tube Surveys

Nest tubes are installed within suitable vegetation, including hedgerows, scrub and woodland. These are checked periodically during the dormouse active season for evidence of occupation, including characteristic nests and dormice.

Dormouse Footprint Tunnel Surveys

Footprint tunnels are a non-invasive survey method used to detect dormouse activity. Tunnels are installed within suitable habitats and contain tracking media that record the footprints of animals passing through them. The tracking materials are checked regularly to establish whether dormice are present.

Dormouse Nest and Nut Searches

Searches for characteristic dormouse nests and gnawed hazelnuts can provide additional evidence of dormouse presence. These techniques may be undertaken alongside other survey methods where appropriate.

When Can Dormouse Surveys Be Undertaken? 

Dormouse surveys are generally undertaken during the species' active season, between April and November, although the optimal survey period varies depending on the method used.

Footprint tunnel surveys are typically undertaken between May and October, while nest tube surveys may extend across the wider active season.

Surveys often require multiple visits over several months. Early consideration of dormice within the planning process is therefore important to avoid potential delays.

Dormouse Mitigation and Licensing 

Hazel dormice and their breeding sites and resting places are protected under UK legislation.

Where development could affect dormice or their habitats, appropriate avoidance, mitigation or compensation measures may be required.

BM Ecology can provide advice on suitable mitigation measures, including habitat retention, sensitive vegetation clearance, habitat enhancement and the provision of dormouse nesting opportunities.

Where necessary, works affecting dormice may require a European Protected Species licence from Natural Resources Wales.