Hazel dormouse

Muscardinus avellanarius

  1. Wildlife
  2. Mammals
  3. Hazel dormouse


The hazel dormouse is an agile climber and mainly nocturnal so is rarely seen. They live in deciduous woodland, hedgerows and dense scrub and spend most of the spring and summer up in the branches rarely coming down to the ground. They eat buds, hazelnuts, berries and insects.

They build summer nests of grasses, stripped honeysuckle bark and fresh hazel leaves in which the female will give birth to up to seven young. They hibernate during the winter months, either on the ground - under logs, leaves, in grass tussocks and at the base of trees - or just beneath the ground where the temperature is more constant. 


How to identify

The dormouse has gingery-brown fur, large black eyes and a fluffy tail; it is much smaller than a Squirrel.

Where to find it

Southern England and Wales.


When to find it

  • April
  • May
  • June
  • July
  • August
  • September
  • October

How can people help

The hazel dormouse is suffering from the loss and lack of management of its preferred habitats (woodland, hedgerows and dense scrub). It is also thought displacement by the introduced edible dormouse (Glis glis) is a problem in the Chilterns. Local Wildlife Trusts are helping by monitoring dormice populations, providing nestboxes and actively managing their preferred habitats appropriately. Coppicing, ride widening, thinning and glade creation in woodland creates the successional stage of woody vegetation preferred by dormice.

Species information

Common name
Hazel dormouse
Latin name
Muscardinus avellanarius
Length: 8cm plus a tail of 6cm Weight: 15-40g Average lifespan: 4 years
Conservation status
Classified as a Priority Species in the UK Biodiversity Action Plan.