The edible dormouse is mainly nocturnal, spending the daylight hours sheltering in a tree hollow, in a nest constructed from plant material, in a rock crevice, or inside an artificial nestbox or human dwelling (2) (3) (4) (6) (7). It will also take over abandoned bird nests and squirrel dreys (3) (7). An agile climber, the edible dormouse is capable of moving down tree trunks head first and can cling from branches by its hind feet. This species spends most of its life in the trees, rarely coming to the ground (3).
The diet of the edible dormouse consists mainly of plant matter, particularly nuts and seeds such as acorns, hazelnuts and beech mast. The edible dormouse also eats berries and other soft fruits, as well as buds, leaves, bark and fungi. Insects are taken occasionally, and this species is also known to eat bird eggs and nestlings (2) (3) (4).
The edible dormouse communicates through a range of squeaks, chirps, whistles and squeals, and it also uses scent to mark its territory (3) (4) (5). Individuals can be quarrelsome and males have been reported to fight aggressively during the breeding season, although small groups of this species have been known to hibernate together (3) (4).
The edible dormouse has a long hibernation period that begins between September and November and lasts until May or June (3) (4) (6) (8). Unlike some small mammals, this species does not store food for the hibernation period, instead surviving on large fat reserves accumulated in late summer and autumn (3) (7). The edible dormouse usually hibernates in a burrow or cavity underground, often under the roots of trees (3) (6) and sometimes as much as a metre below the surface (4). It can also sometimes be found in cellars and attics (3) (6).
The mating season of the edible dormouse occurs soon after individuals have emerged from hibernation, between about June and August (3) (4). Males usually mate with more than one female (3) (5). The female edible dormouse gives birth to a single litter of young (2) (3) (4) (5) (8) after a gestation period of around 20 to 31 days (3). Litter size ranges from about two to ten (4), but nests may contain more young than this as females sometimes share the same nest and nurse each other’s offspring (3) (8).
The young dormice are born relatively late in the year, from around July to September (3) (4) (8), when food is most available (3). The young, which are helpless, naked and blind at birth, open their eyes at about 21 to 23 days old and leave the nest at 30 days old (2) (3). As the young edible dormice are born late in the year, they must grow rapidly to be able to survive the winter (3).
The edible dormouse can sometimes breed in the year following its birth, but some females may not give birth until their third year. This species is unusually long-lived for a small rodent, having a life expectancy of about nine years (3) (8). Some of the key tree species on which the edible dormouse relies for food, including beech and oak, only produce large seed crops every few years, with seed production in the intervening years being low or even failing entirely (3). The edible dormouse’s long lifespan and relatively large litter size compensate for the fact that this species does not usually breed in years of low food availability (3) (8) (9). In non-reproductive years, the edible dormouse has been found to sometimes return to a dormant state underground, being active for only a few weeks of the year (9).