From leaves to litter- Use of anthropogenic nesting materials in hibernation nests of the European hedgehog

Urbanisation and human population growth have significantly increased the presence of anthropogenic materials in natural environments, prompting growing interest in how wildlife may be adapting to these changes. One such behavioural response is the incorporation of human-made materials into animal nests, a phenomenon that has raised concerns due to its potential harmful effects, such as entanglement or ingestion. While this behaviour has been documented widely in birds, it remains underreported in other taxa, partly due to the difficulty of locating nests. In this study, we describe instances of anthropogenic materials (including plastic) being incorporated into the hibernation nests of European hedgehogs, Erinaceus europaeus, as part of a broader investigation into their nesting behaviour during hibernation. These findings suggest that hedgehogs may opportunistically use available anthropogenic materials in nest construction, potentially as a response to urban environments. Our findings help broaden the understanding of mammalian responses to urbanisation and emphasize the need to investigate whether the incorporation of these materials is likely to be harmful or adaptive to hedgehogs or for mammals generally.