Habitat use and movement of Garden Dormice in the Harz Mountains, Germany

The Garden Dormouse (Eliomys quercinus) is an example of an endangered species with a distribution focus in Germany. Little is known about its habitat use and movements. Radio tracking is a common method used to analyze movement patterns to identify specific habitat requirements. During 11 weeks from May until September 2021, we tracked four individuals (2 females, 2 males) in the Harz Mountains National Park (~700 m a.s.l.). The study area was characterized by a predominance of rocks and spruce. Within one hour, males moved a distance of up to 173.95 m, females covered a maximum distance of 155.62 m. We analyzed whether a hiking trail cutting through the study area represented a potential barrier for the movement of these animals. Three individuals were tracked crossing the path up to 4 times a night. Raspberry bushes along the path were a potential incentive for crossing. A dense rocky cover and a well-developed shrub layer with raspberry bushes within spruce woodlands seem favorable to the presence of Garden Dormice. For the conservation of this species, it is necessary to protect similar habitats. To connect areas with populations of garden dormice, it may be important to encourage bushes with wild fruits among forest edges and pathways

Home ranges and activity of Garden Dormice in the Harz Mountains, Germany

For the conservation of endangered species, a good knowledge of their biology is essential. However, due to the secluded lifestyle and nocturnal activity of the Garden Dormouse (Eliomys quercinus), comprehensive research on these small mammals is difficult, resulting in a lack of data. Little is known about the habitat requirements of Garden Dormice in forest habitats. Radio tracking was used to analyze movement patterns to identify specific features of their habitat in the Harz Mountains National Park in Germany (~700 m a.s.l.). Four individuals (2 females, 2 males) were tracked during 11 weeks from May until September 2021. Home ranges were calculated using minimum convex polygon (MCP) and fixed kernel density estimation (KDE) methods. Home range sizes (100% MCP) of males were between 0.58 ha and 7.62 ha and of females between 3.63 ha and 6.39 ha. The size of the core areas (65% KDE) was 0.25 ha - 3.08 ha for males and 1.94 ha - 6.18 ha for females. Whereas the start of their daily activity did not correlate with sunset, the end of activity was associated with sunrise. The females never switched their nesting sites, but the males used 7 -10 nesting sites. Nesting sites were located between boulders and inside deadwood piles. Deadwood is an important habitat for insects which serve as food for Garden Dormice (and other small mammals). To this species in its natural habitat it is necessary to sustain deadwood in forests

Habitats change habits: How Garden Dormice cope with different environments in Germany

The Garden Dormouse is currently disappearing from parts of its range. While its population is declining in many parts of Germany including forest habitats in low mountain ranges, a stable occurrence is found in some cities. A radiotelemetry study was performed in the spruce forests of the Harz National Park (mountains) and the city of Wiesbaden to compare space and habitat use, and the structure and use of daytime nest sites (DNS) used for rest.In total, eight individuals (5 males, 3 females) were tracked between May and September 2021. They used smaller home ranges in the city (MCP100: 2.39 ± 1.34 ha; n = 4) than in the forest (MCP100: 4.56 ± 3.13 ha; n = 4). At night, the animals used structures offering protection from predators and providing food like wide hedges in the city and rock crevices and berry bushes in the forest.The animals were located in a DNS a total of 133 times, and one to ten different DNS per animal were identified. They were situated in structures providing a high degree of protection from predators and also had consistent temperatures (e.g. rock crevices , deadwood piles , hedges, vines on buildings, nest boxes, and buildings). While females rarely changed their DNS, males used several of them.Recommended conservation measures for Garden Dormice include raising public awareness and also the protection and promotion of facade greening, hedges and old buildings in urban areas. A dense rocky cover, as well as a well-developed shrub layer with raspberry bushes are valuable in spruce woodlands