Dormouse Surveys and Mitigation

Durham Wildlife Services have extensive experience in surveying for dormice to assess presence and population status and to identify key breeding, foraging and commuting habitat. Our ecologists hold Natural England dormouse licesnses, and are experienced in the supervision of habitat removal and translocation works.

The dormouse is legally protected under UK and European law and developments affecting these animals or their habitats are likely to require a European protected species licence before site clearance.

Initial Assessment

Signs of dormouse activity can be overlooked; Durham Wildlife Services can carry out a dormouse assessment that tells you the likelihood of your proposed activity encountering a dormouse issue and how to resolve any issue arising as effectively as possible. If evidence of dormice is found hen further surveys are required.

Further Survey Work

Further dormouse surveys must be carried out by a licenced surveyor, these consist of two surveys:

Box and Tube Surveys

The survey involves the erection of boxes or tubes, dormice utilise the boxes and tubes for nesting and shelter. The boxes or tubes are then surveyed on a regular basis to record the presence of these animals.

Nut Search Surveys

Dormice leave distinctive feeding evidence on hazel nuts, nuts located beneath hazel trees are surveyed for evidence of feeding activity.

Licence Application and Mitigation

Before any work commences a development licence must be obtained at least one month in advance of the start date and mitigation measure should be put in place, these may involve the following:

• Trees suspected or known to be used by dormice as nesting sites should be clearly marked and not felled.
• Selected tree lopping, felling and vegetation clearing should only be done outside the dormouse breeding and hibernation seasons.
• Ensure habitat isolation doesn't occur
• Habitat enhancement and creation
• All work has to be supervised by a licensed ecologist.

As dormice receive such high protection it is important that any development occurring doesn't have a negative effect on the population. Development is a good opportunity to enhance the dormouse population through mitigation measures.

Survey Timings

Initial surveys can be carried out throughout the year. Boxes and tubes are put out in March or April and then surveyed on a regular basis between May and October. Nut searches are most effective between September and November when fallen nuts are at their freshest.