Dormouse Surveys

Hazel dormice are the only native species of dormouse in the UK, and it is estimated that their numbers have declined by half since 2000. As such, they are awarded legal protection both nationally and internationally, through the Conservation (Natural Habitats &c.) Regulations 1994 implement EC Directive 92/43/EEC, known as The Habitats Directive. It’s an offence to deliberately disturb, kill, or capture a hazel dormouse, as well as damage or destroy its resting place or breeding site. If a development site is identified as having potential habitat suitable for dormice, further surveys will be required. This will inform the next steps for the development, to ensure the developer operates within the correct legal boundaries, and the overall conservation status of dormice in the locale remains intact, if not enhanced.

To detect dormice on a development site, nest tubes or boxes are placed within dormouse-suitable habitat and checked monthly to determine the presence/likely absence of the mammals. A licensed ecologist will be looking for signs such as nests, food caches or dormice themselves. Nut searches can be undertaken in the autumn and winter to look for hazelnuts that have been eaten by dormice, which chew into the nuts by forming a neat and smooth hole unique to this species. Nut searches however can only be used as an indication of presence and are not commonly used as evidence of likely absence unless deemed suitable by an experienced ecologist. When dormouse presence or likely absence is confirmed on the site, a suitable approach to the development can be recommended. This might include applying for a European Protected Species License (EPSL) from Natural England. Once granted, the license is a legal document that must be adhered to, and works can continue within the manner laid out by the license. This might include, but is not limited to:

• Site clearance at certain times of the year, or in certain amounts to encourage dormice to disburse from the site naturally

• Mitigation for dormice including enhancing nearby woodland, or installing nest boxes with post-development monitoring

• Certain works on site to be overseen by a suitably licensed ecologist (e.g. removal of tree stumps)