Dormouse survey

Hazel Dormice and their habitats are fully protected under the Wildlife and Countryside Act 1981 (as amended) and the Conservation of Habitats and Species Regulations 2010. In summary it is against the law to:

  • Capture, kill, disturb or injure Dormice;
  • Damage/destroy habitat used by dormice for breeding/resting;
  • Obstruct access to habitat used for resting/shelter.

Hazel Dormouse are arboreal (i.e. tree-dwelling) mammals native to the UK. They have undergone considerable population declines in recent decades, in large part due to changes in woodland and hedgerow management and loss of woodland and hedgerow habitat. Whilst rare in much of the UK, their populations are relatively widespread across the South West, thanks in part due to the less intensive agriculture prevalent in the region and the resulting retention of the dense network of hedgerows and hedgebanks associated with the region. They are therefore a common consideration on greenfield development sites,

When a dormouse survey is required

Where developments have the potential to impact (either directly or indirectly) on hedgerows or woodland, it may be necessary to undertake presence / absence surveys for Dormouse to establish the need to mitigate for them. Presence / absence surveys commonly involve deployment of nest tubes in suitable habitat at a site, followed by monthly checks by a suitably licenced ecologist. A scoring system is used to determine absence of the species, whereby each month is allocated points indicating the likelihood of finding Dormouse within that month. According to standard survey guidelines (English Nature, 2006) total of 20 points must be achieved to confirm absence. This commonly equates to surveys running from e.g. May to September or June to November. Therefore the need for Dormouse surveys can have significant impacts on projected works programmes if not considered at an early stage.

As a supplementary measure, where fruiting Hazel is present on a site a nut search can be undertaken to look for signs of Dormouse foraging. This survey technique cannot be used to confirm absence, only presence, and is normally used in conjunction with more traditional survey methodologies (as above).

The European Protected Species Licence

Due to the legal protection received by Hazel Dormouse, where presence at a site is confirmed it may be necessary to obtain a European Protected Species Licence (EPSL) for any works which might impact on the species such as removal or degradation of suitable habitat. Natural England do not charge for issue of these licences, however they can take up to 30 working days to process applications. Furthermore seasonal constraints apply to licensable works as Dormouse hibernate during winter months. Burton Reid have experience in successfully applying for licences for works affecting Hazel Dormouse, and are able to provide staff with personal licences for handling Dormouse to undertake surveys and licensable works.

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