Investigating the greater white-toothed shrew invasion in Great Britain

The greater white-toothed shrew (GWT: Crocidura russula ) was first reported in northern England in 2022. We detail the immediate investigation through national authorities, non-government bodies and individuals. Among 595 small mammals captured there were 16 GWT, and owl pellet analysis revealed 56 GWT skull from 11 sites. This confirmed a relatively widespread distribution of GWT in two locations and genetic analysis suggests these population were derived from one or more continental European introductions, but not from the nearby island of Ireland where this non-native species has been present since at least 2007. The overall government response concluded that the species is too widespread to have any reasonable chance of eradication, but there remain ongoing efforts to determine the extent of invasion and effect on native species.