Alpine forests are a suitable habitat for the Hazel Dormouse

The Hazel Dormouse (Muscardinus avellanarius) is commonly considered a typical lowland species, occasionally observed at higher elevations in mountain habitats. This study began with preliminary investigations in the Gran Paradiso National Park in the Western Alps, where nests of Hazel Dormice were observed at around 2000 m a.s.l. In 2019, a mark-recapture project started in two valleys (Valsavarenche and Val di Rhêmes), positioning six grids with 40 nest boxes from 1000 m to 2000 m a.s.l. to investigate the ecology and adaptations of dormouse populations along the altitudinal gradient. In these years, nest boxes were checked irregularly, and the number of marked animals was low. The number of individuals captured in the highest grids at 2000 m increased from 1 to 8 in Valsavarenche and from 11 to 15 in Val di Rhêmes. These results seem to confirm a continuous presence of the species at the upper edge of the forest vegetation. The data from Valsavarenche suggest some significant population fluctuations, but the effect of nest boxes on population densities cannot be excluded.