Habitat and space use of the garden dormouse (Eliomys quercinus) in urban and forest habitats in Germany

Abstract The garden dormouse (Eliomys quercinus) inhabits a wide range of habitats, from urban areas in warm temperate lowlands to cool mountain ranges. Despite its adaptability, it has largely disappeared from its former range. While most forest populations in Germany are declining, some populations in cities remain stable. To better understand the ecology of this endangered species, VHF telemetry studies were conducted. Between May and September in 2021, 2022, and 2023, 19 adult individuals (7 males, 12 females) were tracked between 15 to 79 days. The animals were assigned to one of three habitat types: ‘Urban’ (entirely human-modified areas, n = 7), ‘Forest’ (forest habitat with minimal human presence, n = 6), and ‘Mixed’ (a combination of forest and human-modified areas, n = 6). Garden dormice had the largest home ranges (MCP100) in ‘Forest’ habitats (4.06 ha) followed by ‘Mixed’ (1.2 ha) and ‘Urban’ habitats (0.56 ha). They preferred structures with high coverage and proximity to food resources, such as structurally rich plant communities (‘Urban’), rock crevices and ruderal shrub vegetation, including berry bushes (‘Forest’). Nest sites offered protection from predators and a stable microclimate, and were predominantly located in buildings (‘Mixed’, ‘Urban’) and rock crevices (‘Forest’). They were changed frequently. Garden dormice occupied smaller home ranges in areas where human-provided resources were concentrated in a small space. Although garden dormice habitats and the resources they use differ in appearance, they fulfill the same ecological needs: sufficient food, safe movement through the habitat and secure nest sites.