Supporting Hazel Dormice

A tiny golden guardian of our ancient woodlands - Hazel Dormice may be small, but they play a vital role in our landscape.

Weighing no more than a few coins, these adorable little mammals are rarely seen – and for good reason. Dormice spend most of their day sleeping, tucked away in cosy nests of grass and leaves. But once night falls, they spring into action, climbing high into the treetops searching for food like hazelnuts, berries and insects.

Once widespread and common across the UK, the dormouse has suffered a major decline over the past century and is now at risk of extinction. The main cause? The fragmentation of its woodland habitat, loss of ancient hedgerows and changes in woodland management. Dormice are reluctant to cross open ground, so when their habitat becomes too small or fragmented, vital habitat corridors are cut off and local populations can quickly vanish.

As a woodland edge species, dormice depend on well-managed deciduous woodlands and thick, overgrown hedgerows that provide a variety of continuous flowers, fruits, and nuts throughout their active months. In winter, they require mature trees with cavities to nest and hibernate in. They’re also an important indicator species, often signalling the presence of a healthy, biodiverse woodland.

Image credit: Somerset Wildlife Trust

Hazel dormice are a protected species and a key focus of the Connecting Constable & Gainsborough Country project. There are only a few remaining strongholds in the project area, typically within nature reserves with managed woodland and active coppice management – including Arger Fen, Groton Wood and Bradfield Woods. Historic records also show populations in Essex, including recent sightings at Essex Wildlife Trust reserves, suggesting some may still remain here.

The project aims to restore and reconnect key dormouse habitats, strengthening corridors between woodland SSSIs. Managing hedgerows will also be crucial: cutting only every three years or coppicing every 15 years and avoiding cutting in autumn, especially during mild winters when dormice could be hibernating above ground. In the future, there may be a chance for translocation projects to encourage populations to spread wider.

By creating a more connected and resilient landscape, we can help give the hazel dormouse, along with other target species that require similar habitat and connectivity, a fighting chance for the future.