Feeding on the edge: the diet of the hazel dormouse Muscardinus avellanarius (Linnaeus 1758) on the northern periphery of its distributional range

Although the hazel dormouse Muscardinus avellanarius is considered both a highly specialized and a threatened mammal species in Europe, it is relatively common and widespread in Lithuania, situated on the northern periphery of its distributional range. We studied dormouse diet over the entire activity season using microscopic analysis of feces to gain a better understanding of its ecology. Our results confirm that the hazel dormouse is indeed a selective feeder, always showing a preference for the reproductive parts of plants. However, the plant species used by dormice in Lithuania are different from those used in other parts of the dormouse range (e.g., England). In Lithuania, the main dormouse food sources are the inflorescence of willow, oak, and spruce in spring; the berries of honeysuckle, raspberry, and glossy buckthorn in summer; and the berries of glossy buckthorn, oak acorns, and hazelnuts in autumn. Only in early summer, the proportion of food of animal origin is high. The berries of glossy buckthorn are very important to dormouse for feeding and accumulation of fat reserves in autumn. The adaptability of dormice to feed on local plants, as well as the sufficient diversity of food plants in their habitats, allows these animals to be relatively common and widespread on the northern periphery of their range.