The western European hedgehog Erinaceus europaeus L. 1758 on San Pietro Island (southern Sardinia, Italy) and an updated review of its presence on the Italian small islands

The current presence and local distribution of the western European hedgehog Erinaceus europaeus L. 1758, on San Pietro Island (Southern Sardinia, Italy) are here discussed for the period 2013-2021 with a short review of the species’ occurrence on the small Italian islands. The species was found in the central-eastern sector of the island, which is characterised by a high urban and infrastructural density and an agricultural mosaic, both suitable ecological conditions favouring its presence. Most of the direct data were obtained from roadkills. Despite the elusive behaviour of the species and the consequent possible underestimation, it can be assumed that the species shows a low density. In this respect, it might be interesting to investigate whether local limiting factors, either anthropogenic or natural might act on the hedgehog population. At a larger scale, the updated review of the small Italian islands shows the presence of the species on 13 islands, of which probably only Elba, Asinara and San Pietro (all >50 km2) support established populations. Further research is needed to study anthropogenic origin, history of introduction, genetics, density and medium-long-term viability of these small populations in each insular context.