Genetics reveals that free-ranging chipmunks introduced to Italy have multiple origins

The Siberian chipmunk Eutamias sibiricus is native to north-eastern Asia, but alien populations, mostly composed by a low number of individuals, have been established in many western countries through the pet trade. Large native ranges, such as that of Siberian chipmunks, and number of introduction events may explain the establishment success of alien mammals. In Italy, the largest population of Siberian chipmunks occurs in an urban park of Veneto (NE Italy), whereas other 3 nuclei are currently composed by less than 10 individuals. In this work we aimed at assessing the origin of Siberian chipmunks introduced to Italy. We analyzed a region of the mtDNA gene cytochrome-b to infer the native geographic range of chipmunks introduced to Italy. Our genetic analysis (N = 8 samples) revealed a multiple origin of alien chipmunks in Italy, with individuals from Siberia (collected in Rome) and from Korea (collected both in Rome and northeastern Italy), with Korean chipmunks (i.e. those also present in central Europe) showing the highest invasive success. The ongoing taxonomic splitting of his species, if accepted by the scientific community, will require a revision of the European Regulation 1143/2014, which currently bans the trade of Siberian chipmunk only, with no explicit consequences on Korean and Chinese taxa.