Hazel dormice: advice for making planning decisions
How to assess a planning application when there are hazel (common) dormice on or near a proposed development site.
Applies to England
This is Natural England’s ‘standing advice’ for hazel (common) dormice. It is a material planning consideration for local planning authorities (LPAs). You should take this advice into account when making planning decisions. It forms part of a collection of standing advice for protected species.
Following this advice:
- avoids the need for you to consult on the impacts of planning applications on hazel dormice in most cases
- can help you make decisions on development proposals
You may need a qualified ecologist to advise you on the planning application and supporting evidence. You can find one using either the:
- Chartered Institute of Ecology and Environment Management (CIEEM) directory
- Environmental Data Services directory
Qualified ecologists will follow the Dormouse Conservation Handbook published by CIEEM. This document may not be accessible to assistive technology.
How hazel dormice are protected
Hazel dormice are designated and protected as European protected species (EPS). EPS are protected under the Conservation of Habitats and Species Regulations 2017.
It is an offence to:
- deliberately kill, injure, disturb or capture them
- damage or destroy their breeding sites and resting places
- possess, control, transport (alive or dead)
It is also an offence under the Wildlife and Countryside Act 1981 to intentionally or recklessly:
- disturb hazel dormice while they occupy a structure or place used for shelter or protection
- obstruct access to a place of shelter or protection
Hazel dormice are listed as rare and most threatened species under Section 41 of the Natural Environment and Rural Communities Act (2006). You must have regard for the conservation of Section 41 species as part of your planning decision. Find out more about your biodiversity duty.
The developer must comply with the legal protection of hazel dormice.
You should consider if the developer has taken appropriate measures to avoid, mitigate and, as a last resort, compensate for any negative effects on hazel dormice.
The developer may need a wildlife licence to carry out their proposal.
When to ask for a survey
You should ask for a survey if:
- distribution and historical records suggest dormice may be present - you can search the National Biodiversity Network Atlas by species and location
- the development will affect an area of woodland, hedgerow or scrub suitable for dormice
Absence of a record does not mean there are no hazel dormice. It could mean there is no survey data available for that location.
Surveys need to show whether hazel dormice are present in the area or nearby, and how they use the site.
Survey work can include:
- visual searches for nests and opened hazelnuts - for smaller projects, such as creating gaps in hedgerows or removing a small amount of bramble scrub
- using nest tubes and boxes - for more damaging projects or licence applications
If hazel dormice are found on part of the site, you can assume they’re present in suitable habitats on the whole site.
Unless the proposal will have a low impact on hazel dormice, the survey should also include an assessment of the site’s importance. Factors to consider include:
- the presence of other dormouse populations in the area
- whether dormice are widespread or limited to a few sites
- location of the population relative to dormouse range
- habitat composition
- predicted densities
The survey should be from the current or previous active season. Surveys up to 3 years old are acceptable if the habitats have not significantly changed.
You must check if the ecologist is qualified and experienced to carry out surveys for hazel dormice. CIEEM publishes:
- competencies required for species surveys
- advice on the valid age of data
These documents may not be accessible to assistive technology.
The ecologist should also follow the Biodiversity code of practice for planning and development (BS 42020:2013) available on the British Standards Institute website.
Assess the effect of development on hazel dormice
Developers should submit qualitative and quantitative information with their planning application on how their development avoids or mitigates harm to hazel dormice.
Activities can harm hazel dormice if developers:
- handle them
- disturb them, for example from noise and using light or woodland and hedgerow management
- remove habitat, such as clearing woodland for a new road causing habitat fragmentation and isolating dormice populations
- remove foraging habitat
- remove or change habitats in a way that affects the dormouse population and increase the risk from predators
- remove hedges or other linear habitat that links populations
Post-development effects could include increased:
- disturbance from people, for example from a new housing development
- risk from predators like domestic cats introduced by new homeowners
Avoidance, mitigation and compensation measures
Look for examples of avoidance, mitigation or compensation plans in the development proposal.
To avoid possible effects on hazel dormice, developers could redesign the proposal to:
- leave dormice habitat in place
- alter the timing of works
- change the methods of working
Where this is not possible, mitigation and compensation measures could include:
- creating new habitat by planting new areas or using dormouse boxes
- creating links to other habitats, for example bridges with a gap less than 100 metres
- improving existing habitat, for example thinning, coppicing and new planting
Mitigation measures could also include coaxing the dormice to a location nearby by clearing sections of habitat. The remaining habitat must be linked to a larger hazel dormouse habitat.
If there is no reasonable alternative habitat close by, the proposal could include capturing hazel dormice and moving them to a different location, known as translocation. The new habitat must be capable of supporting the dormice. The proposal should include evidence that translocation would benefit dormice conservation.
If translocating hazel dormice, the proposal will need a suitable receptor site. The new site should:
- keep dormice within their home range
- not have a dormice population already
- be ready before translocation takes place
For more information on mitigation plans and compensation measures, read the planners guide for protected species and development.
Planning and licence conditions
If the proposal is likely to affect hazel dormice, the developer must apply for a hazel dormice mitigation licence.
Before you can grant planning permission, you must:
- make sure any mitigation or compensation conditions you impose do not conflict with the requirements of a mitigation licence
- be confident that Natural England will issue a licence
You do not need to consult Natural England on the wording or discharge of any conditions you impose on a planning proposal. Natural England is unable to provide advice on this.
Enhance biodiversity
To meet your biodiversity duty, you should suggest ways for the developer to:
- create new or enhanced habitats on the development site
- achieve a net gain in biodiversity through good design, such as green roofs, street trees or sustainable drainage
Site management and monitoring
You should consider the need for site monitoring and management. These measures are likely to be needed by protected species licences.
A site management and monitoring plan should include:
- managing vegetation
- checking the availability of nesting habitats
This can also include additional survey work to check that mitigation measures are working as intended, followed by remedial work if needed.