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The hazel or common dormouse is protected under UK and European law.

Hazel dormouse (Muscardinus avellanarius) is a member of the order Rodentia (rodents), the largest order in the mammalian kingdom. 

You’re likely to need dormouse surveys if distribution and historical records suggest dormice may be present and/or the development will affect an area of woodland, hedgerow or scrub suitable for dormice habitat. Development-related activities that can negatively affect hazel dormice include:

  • Disturbance, e.g. noise and light, to woodland and hedgerows
  • Habitat removal, clearing woodland and removing hedgerows
  • Habitat fragmentation and isolation

In most cases it is possible to avoid harming hazel dormice or damaging or blocking access to their habitats. If your project can’t avoid this we can apply for a mitigation licence on your behalf.

What does a survey entail?

A hazel dormouse survey involves the temporary installation of special nest tubes and/or nest boxes, which can be combined with searches for dormouse nests and chewed hazelnuts. A dormouse-licenced ecologist should undertake the survey, which we can provide.

You can limit surveys to searches for nests and opened nuts if the work only involves losing a small amount of habitat (e.g. gaps in hedgerows) or removing a small amount of bramble scrub.

When is the right time to carry out a dormouse survey?

Exact timings vary, depending on the survey type, where you live and what the weather is like at the time. We recommend checking with us first to avoid any unnecessary delays to your project. The following timings provide a general guide.

Green = optimal | Yellow = suboptimal | White = unsuitable

How can Ecology Resources help?

This page is just an introduction. We offer free advice regarding all dormouse survey matters, including how your project may be affected by their presence, or how you can tweak you project design to ensure a biodiversity net gain is achieved. To discuss further, feel free to ring us during office hours or email us at anytime.

A few examples of dormouse projects we have successfully delivered for our clients

Presence / absence survey,
Presence / absence surveys,
Milton Keynes
Dormouse breeding monitoring surveys, Sussex
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