What's happened?

Dormice are already extinct in some areas of the UK, having once been widespread throughout much of Britain. Our Dormice in Danger Appeal aims to help reverse this devastating decline at a local level.

Hazel dormice are now only present in Wales and southern parts of England. A long-term decline continues across their range. It is thought that their range has shrunk by around a half in the last hundred years. National monitoring shows the population has fallen by a third since the end of 20th century.


The decline is ongoing, since 1993 dormouse populations have declined by 72% despite high level of species protection and widespread conservation measures (Goodwin et al, 2017).


The hazel dormouse is a UK Biodiversity Action Plan Priority Species and European Protected Species listed under Annex IV of the European Habitats Directive (1992) and is protected under the UK Habitats Regulations.

Reasons for their decline

Dormice need well-managed woodlands connected by hedgerows so that they can spread. But changes in woodland management, farming practices, loss of hedgerows and the fragmentation of woodland have all taken a heavy toll on their living space.

Habitat loss and fragmentation 

  • The loss of woodland since the early 20th century and the removal of hedgerows as farming intensified after 1945, have reduced the extent of available habitat.
  • Remaining patches of habitat are increasingly isolated, restricting movement between populations and increasing the risk of extinction of individual populations.

Changes in woodland and hedgerow management

  • Dormice need traditionally managed woodland, they thrived when hazel trees were regularly cut back (coppiced) because this provided plenty of fruiting trees for food.
  • Woodlands which aren't coppiced become less structurally diverse, with fewer open spaces and less new understorey growth that provides food and nesting sites for dormice.
  • Despite the revival of coppicing in some areas, many woodlands have changed too drastically to support dormice.
  • We have lost two-thirds of our nation’s hedgerows and the lack of traditional management is making matters worse for the dormouse.
  • Hedgerows tend to be managed by flail cutting, which leaves less suitable and available habitat for the dormouse and results in populations becoming increasingly isolated.

Changing climate and unpredictable weather

  • Poor weather adversely affects foraging and breeding success, as well as winter survival rates.
  • Hazel dormice hibernate over winter, and are active April - October. If the weather is bad during this time they undergo periods of ‘torpor’ (dormouse fur is not weatherproof and they will avoid rain).
  • This sensitivity to weather conditions suggests climate change – with warmer, wetter seasons and more extreme weather events – is likely to affect dormouse populations. 


 With your support, we can save them before it is too late.