Among invasive squirrels in Europe, the Siberian chipmunk Eutamias sibiricus, native to North-East Asia, shows the highest number of free-ranging populations in European countries, due to the intense pet trade it underwent between the 1960s and the 1980s. We describe 628-bp cytochrome b sequences from the Netherlands (N = 3), Belgium (N = 4) and Switzerland (N = 1), and through phylogenetic analysis show that they belong to the Korean subspecies. This confirms previous findings that the Korean subspecies (Eutamias sibiricus barberi) has been the most commonly introduced to Europe. Another subspecies (the Northern subspecies, Eutamias sibiricus sibiricus) has only been reported previously in an Italian free-living population. If the splitting of the Korean taxon as a proper species (Eutamias barberi) will be confirmed by analysis of nuclear markers, a revision of the European Regulation 1143/2014 should be conducted to explicitly ban the trade of newly identified taxa.

Support to MM for this research (grant LCF/BQ/DR20/11790020) was provided by ‘La Caixa’ Foundation (ID 100010434).