Dormice

The hazel dormouse (Muscardinus avellanarius) is a small rodent but is not a true mouse. It can be identified by its distinctive furry tail, golden coat and black eyes. The hazel dormouse inhabits woodland where it lives on nuts, berries, pollen and small insects, by foraging at night. Often, it can be found sleeping in its nest by day.

This characteristic of sleeping by day and its habit of hibernating through winter have given rise to its name, probably from the French dormir – to sleep.

The animal is relatively long-lived for a small mammal, having a life expectancy of 4-5 years. The female generally has only one litter of young per year. During its life it stays within a small area; it does not move far from where it was born.

The hazel dormouse is an important subject to monitor because it is considered to be an “umbrella species” in that, if the conditions are right for it, they will be right for many other woodland species, too.

Dormouse distribution 2013, source JNCC

In the UK, the hazel dormouse is only found in England and Wales but even here the range is shrinking. It has become extinct in half of its former range in the last 100 years and is now concentrated in the southern counties. The reason for this decline is believed to be habitat loss and a deterioration in woodland management.

Because the hazel dormouse is threatened by extinction, it is protected under the Wildlife and Countryside Act 1981 so it cannot be deliberately disturb unless under special licence.

The hazel dormouse is the only UK native dormouse and it is the subject of our work.

The other UK species, the edible dormouse (Glis glis) was introduced into the UK in 1902 and it is only found in the Chiltern Hills.