The Common Dormouse
(Muscardinus avellanarius)

The common dormouse must be considered as one of our most attractive small mammals, which, despite its name, it is far from being common. They are easy to tell from other small mammals, as they are a bright golden colour with a thick furry tail and big black eyes. With a body length of about 7cm and a tail of similar length, dormice are quite small. During the summer an adult would weigh around 17-20 grams, doubling this prior to hibernation in late Autumn. Dormice are mainly found in deciduous woodlands and old thick hedgerows, although there have been reports of them on the edges of conifer plantations. The Dormouse year starts in late April early May when they emerge from hibernation. They usually take to a nest box or natural tree hollow where they build a woven nest from honey-suckle bark or similar. The weather at this time can still be quite variable. So during bad weather or when food is in short supply they go into a form of semi-hibernation termed torpor which helps save valuable energy. Dormice are nocturnal and because they have a varied diet that is depend- ent upon various flowers, pollen, fruits, nuts and insects, they spend a lot of their time looking for food high up in the trees. They rarely go far from their nests and most keep within 50 metres of it although males tend to roam more than females. Actual distances travel-led each night can vary according to the time of year and availability of food. Dormice breed from mid June onwards, usually producing one litter of 4 - 5 young. The young are born pink, blind and helpless. By 18 days their eyes are open and they have grey-brown fur. They will remain with their mother for 6 - 8 weeks. Before the onset of winter both the adults and especially the young have to fatten up, ready for hibernation. Hibernation usually begins some time in October. Currently the Ranger Service only has one known site with dormice present. Here we provide over 80 nest boxes for the dormice to use. One of my jobs is to monitor them once a month from arch-November. This is carried out under a special licence from English Nature. Over the last three years my records show a small but steady increase in numbers.


Phil Horwood (WDC Ranger Service)