For any development which may require planning permission from your local planning authority (LPA), the LPA need to fully consider the likely ecological impacts of the proposed works.

The hazel dormouse is fully protected under both national and European nature conservation legislation. In brief, these legislative instruments make it an offence to intentionally or recklessly kill, injure or capture any hazel dormouse. Places of shelter used by the species are protected from disturbance while in use, as well as damage, destruction or obstruction. They are nocturnal, largely arboreal, and active only from April to October, hibernating the remainder of the year which means observations are uncommon. Signs of dormouse such as nests or nibbled hazelnuts are easier to find. Dormice targeted surveys may be required if there is evidence that they are likely to be present on-site, or if there cannot be confidence that they are not utilising the site during an ecological appraisal of the site. Surveys for dormice using nest tubes take place between March and October and nut searches are best undertaken from September to November.

What can affect dormice?                                          

  • Removal of trees or hedgerows

  • Changes to woodland management

  • Climatic instability


enims suitably qualified ecologists undertake:


  • Habitat assessment to evaluate likely presence and to identify further surveys if required

  • Dormouse surveys using a range of methodologies as required

  • Regular nest box/tube checks over the optimal survey period

  • Additional checks for other signs such as nut searches over the optimal period

  • Applications for European Protected Species Mitigation licences

  • Translocation and mitigation for hazel dormouse


Nest Tubes

Using at least 50 nest tubes placed 15 to 20 meters apart, a licenced ecologist will leave the tubes out for the whole dormouse season and will check them at least every two months.

Nest Boxes

Nest boxes are sometimes used alongside nest tube surveys. They will increase the probability of finding dormice and be useful for monitoring the dormice population post development.

Hazelnuts for Dormouse Marks

This method is only used alongside another survey method and in areas dominated by fruiting hazel trees.


Translocation should only be used if there is no other option. A suitable receptor site should be identified before translocation and it should not already have a dormice population.

If you require support for your project please call the enims team on 0845 644 0196.