The life strategy of the hazel dormouse is to hibernate at ground level over winter and to spend the spring, summer and autumn months active in the tree and shrub canopy. On waking from hibernation around April, dormice take advantage of early buds, flowers and small insects to feed and regain weight lost during hibernation, in preparation for breeding. Mating can take place as early as May and after a gestation period of about three weeks, the first litters can be born in late May or early June.
In Britain early litters are relatively unusual and mating usually occurs in either June or July, with the majority of litters born in either July or August. Litter size is approximately four and they are born blind, pink and naked. Young dormice remain in the nest where they are cared for by their mother for approximately four weeks after which they become independent. The young animals
can be separated into distinct stages of development which are pinks, grey eyes closed and grey eyes open (these are the unweaned young stages) after which they are recorded as juvenile (post-weaned young of year) and adult (an animal that has surveyed its first hibernation).
grey eyes closed
grey eyes open