St Kilda Field Mouse

The St Kilda field mouse (Apodemus sylvaticus hirtensis) is a subspecies of wood mouse that is endemic to the Scottish archipelago of St Kilda, which is 40 miles west of Benbecula in the Outer Hebrides, and 100 miles (160 km) from mainland Scotland. Unique to the islands, the mouse is believed to have arrived on the boats of Viking settlers more than a millennium ago. It is not to be confused with the St Kilda house mouse, a species which is now extinct.

The last remaining human inhabitants of St Kilda abandoned the islands on 29 August 1930. Thereafter the mice that survived, even those occupying houses abandoned by the St Kildans, were field mice that had moved into the houses from the hills. The islands' house mice could not survive the harsh conditions for more than two years after the archipelago was abandoned by its human population. The islands currently have temporary human habitations. While field mice are widespread on Hirta, their concentration is more pronounced in the old village areas where holes provide access into buildings. Though rarely observed by casual visitors, the mouse is actually very common, and is present in every part of the habitat, from the harbour to the highpoint. The field mice can survive by eating snails, insects, moss and seeds, can feed on the carcasses of dead sheep and birds, and will also readily eat food brought in by visitors and intended for their own consumption.