Very different to the Common Dormouse has it is about twice the size and lacking any orange in the pealage. It can be easily be confused with the grey squirrel because of the bushy tail and greyish colour but the small hind feet distinguish it from the grey squirrel. Head and body about 150mm with the tail up to 150mm and weighing up to 185g
In Great Britain the Fat Dormouse is confined to a small area in the Chiltern Hills although its range has been increasing since its introduction from Hungary to Tring Park, Herefordshire in 1902 by Walter ( later Lord) Rothschild.
Fat Dormice live together in loose groups without any strong hierarchical ranking. Males become aggressive during the mating season and exhibit a variety of threatening postures. They have small home range of about 100m in diameter and are very agile climbers and spend most of their lives in the canopy of trees although they will readily enter lofts of houses. They can even climb glass. Entirely nocturnal spending the day asleep in a tree hole or nest built close to a trunk and may even use old birds nests. The diet varies according to the season and they will take all kinds of fruit, nuts, buds bark, insects carrion, fungi and sometimes eggs or nestlings.
The Fat Dormouse reaches sexual maturity after the first winter and breeding starts mid June and ends in August with a litter size of between 4 and six but sometimes up to 11. The young are blind at birth with the ears shut and by 30 days the young have left the nest
Tawny owls are probably the most important predators in Britain but they are also taken by stoats, weasels and cats. Poor mast years also have a significant mortality rates to young in winter.
Were once favoured food with the Romans who reared them in oak and beech groves and fattened them in for the table in special jars called Gliraria thus giving them the other name of the Edible Dormouse.
The Fat Dormouse can cause considerable damage to forestry plantations and also to lofts where they chew through cables, plaster and underfelt.
All Gliridae are protected under the 1979 Berne Convention on the Conservation of European Wildlife and Natural Habitats, to which the united Kingdom is a signatory. The fat Dormouse is included under 2 sections of the 1981 Wildlife and Countryside Act, precluding trapping without a licence and introduction into the wild.
Corbet, G.B. & Harris, S. (1991) The Handbook of British Mammals (3rd edn.). Blackwell, Oxford.
Morris, P.A. (1993) A Red Data Book for British Mammals. The Mammal Society, London.