Dormouse Surveys
Dormice in the UK are protected under the Wildlife and Countryside Act 1981 (as amended) and the Conservation of Habitats and Species Regulations 2017. It is an offence to intentionally kill, injure, disturb or take dormice, or to damage, destroy or obstruct access to their nests or resting places without a licence. Even features with potential dormouse habitat must be considered early in the planning process to avoid legal or planning delays.
Hazel Dormice & the Law
When is a Dormouse Survey Required?
Dormouse surveys are typically needed where proposed works could affect habitats suitable for dormice, including woodland edges, hedgerows, scrub, and dense vegetation. Surveys may be requested as part of a planning application even if dormice have not been previously recorded, because the presence of suitable habitat alone can trigger survey requirements. Early assessment helps establish whether surveys are needed and aligns survey timing with planning timescales.
A Phase II dormouse survey is undertaken by setting out nest tubes and/or boxes in woodland (particularly around hazel) and hedgerows. The tubes and boxes are checked multiple times between April and November to search for evidence of dormice, including droppings, summer nests, or the animals themselves. The ground can also be checked for gnawed hazel nuts, which can be carried out at any time of year, although late autumn is preferred.
Dormouse surveys are seasonally dependent, because detectability varies throughout the year. Presence/absence surveys are usually carried out between May and September, when dormice are most active and nests are most detectable. Conducting surveys during the correct period ensures robust results that planning authorities can confidently use to assess impacts and mitigation requirements, and helps avoid the need for additional survey work later.
Phase II dormouse survey
A typical dormouse survey may involve:
Targeted habitat assessment to identify suitability for dormice
Presence/absence survey visits following best practice guidance
Identification of evidence such as nests, feeding signs, or gnawed hazelnuts
Assessment of potential impacts from proposed development
Recommendations for mitigation, avoidance or licence support where needed
Surveys may be carried out as standalone work or as part of a broader ecological appraisal, depending on site context and project requirements.
A Dormouse Survey Includes:
If it is possible ecological mitigation for dormice should be avoided and the areas of hedgerow or woodland retained and protected during development. If this is not possible then a European Protected Species Licence would be required from Natural England and a detailed strategy of mitigation and compensation implemented.
Mitigation
Dormouse bridge
Animex has developed an arboreal wildlife bridge in association with the People's Trust for Endangered Species, which can help mitigate and connect fragmented dormouse habitat. The bridge can be installed in a custom design to ensure the most effective and pragmatic solution for each site. Watch the video presentation below to learn more about the effectiveness of the Animex wildlife bridge.
Our Dormouse Experience
Ecosupport has several experienced dormouse surveyors and a licensed dormouse worker with considerable expertise in survey, evaluation and mitigation for dormice. We have obtained a number of European Protected Species licences for our clients to deliver beneficial and pragmatic mitigation to meet planning conditions.
FAQ’s
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Dormouse surveys are usually required where proposed works could affect habitats suitable for dormice, such as woodland edges, hedgerows or scrub. Suitable habitat can trigger survey requirements even if dormice have not been previously recorded.
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Presence/absence surveys are typically undertaken between May and September, when dormice are active and nests are most detectable. Surveys outside this window may not provide definitive results.
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If dormice are confirmed, mitigation measures or a European Protected Species licence may be required. Our reports provide clear guidance to help with mitigation planning and any necessary licence applications.
Have more questions?