Solitary vs communal use of nest boxes by the Edible Dormouse (Glis glis)

The Edible Dormouse often forms group associations in den sites. We characterize, over a 13-year period, how often the dormice rest alone or communally in nest boxes. The majority (87%) of individuals are solitary, resting alone during the daytime in nest boxes. In communal associations, groups of two or three individuals were the most common. We assessed the role of ambient temperature, seed mast, density of nest boxes and the surrounding vegetation on occupancy patterns. Seed mast and nest box density had a significant effect on group associations. Groups were more common in non-masting years. The lower the density of nest boxes at the study sites, the more common were group associations. In addition, a higher proportion of beech trees surrounding the nest boxes was associated with more frequent group associations.