Unravelling the seasonal dietary dynamics of the endangered garden dormouse (Eliomys quercinus) in Flanders, Belgium

The garden dormouse (Eliomys quercinus) faces significant population declines across Europe, prompting urgent conservation measures. A critical aspect of these efforts is understanding the species' dietary composition and preferences within specific areas and how this changes throughout the year. We compared garden dormouse diets between two habitats in West Flanders, Belgium with faecal analysis from May to October, covering almost their entire active phase. Our findings revealed a diverse diet of both plant and animal matter, with notable variations between habitats and seasons. Blackberries and other fruits, leaves, and to a lesser extent flowers, were the predominant plant-based food sources in both study areas, with seasonal fluctuations indicating a dietary shift throughout the dormice's active period. Spring diets consisted primarily of young leaves and flowers, changing to increased fruit consumption in summer. Beetles emerged as a main animal food source throughout the entire active period. Snails were prominently eaten in the woody area, while millipedes prevailed in the diet in the dune environment, both more in spring than later in the active season. These insights highlight the importance of maintaining diverse fruit sources and preserving beetle, snail, and millipede populations for garden dormouse conservation. This study provides valuable insights into dormouse dietary preferences and thus contributes to targeted conservation strategies being essential for the survival of the dormouse.